Note: Descriptions are shown in the official language in which they were submitted.
CA 02604405 2007-11-01
Patent Title
Digital UHF/VHF Antenna
Inventors
Brad Lee Eckwielen and David LeRoy Hagen
100011 This application claims the priority benefit of Non-Provisional
Application US "Digital
UHF VHF Antenna" US Application Number 11/731,081 filed on 31 March 2007. The
technology
described herein is further described in the Non-Provisional Application
"Modular Digital UHF VHF
Antenna" US Application Number 11/731,132 filed on 31 March 2007.
BACKGROUND OF THE INVENTION
Field of Invention
[0002] This invention relates to antennas suitable for digital signals to
increase the gain for
receiving and/or transmitting signals in the Ultra High Frequency (UHF) and/or
Very High Frequency
(VHF) ranges.
Description of the Related Art
100031 Marginal Performance: Digital Television (DTV) including High
Definition Television
(HDTV) is displacing analog TV because of its much higher image resolution.
However, DTV requires a
minimum signal level to be useable. DTV signals below this threshold level
typically result in no picture
at all. E.g., while the US Federal Communications Commission (US FCC) requires
a minimum 15.2 dBa
Signal/Noise ratio, signals often cut out below about 17 dBa Signal to Noise
(S/N) ratio compared to a
strong signal having a S/N ratio of about 33 dBa. Multipath signals can cause
serious reception problems,
especially in urban areas. Signals with borderline Signal/Noise ratios result
in pixilation and other
unacceptable distortions. Relevant art UHF antennas are typically configured
for at higher frequencies than
the USA's digital TV channel allocations. Antennas designed UHF half wave
dipole resonance have low
VHF performance. The US FCC expects that many consumers will need to obtain
new antennas for free
to air DTV reception.
[0004] Corrosion: Typical antenna installations allow moisture to enter coax
connectors and coax
lines. This causes outside and even inside connector corrosion resulting in
major signal attenuation over
time. Many antennas use steel rivets or screws to hold aluminum elements, or
to connect copper cables to
steel connectors. Galvanic action corrodes contacts, increasing electrical
impedance and degrading signal
reception and/or transmission over time.
[0005] Wear: VHF and UHF antennas are commonly folded for shipment. Wind
flexing ofriveted
or screwed elements causes joint movement and wear, loosens connections, and
increases signal loss with
time. Flimsy plastic or light metal element mounts frequently break, bend, or
work loose in storms. Miss-
alignment and/or loose or lost connections seriously degrade antenna gain.
[0006] Impedance mismatch: Most VHF prior relevant art utilizes 300 ohm
antenna feed points.
These antennas require impedance converters ("baluns") from 300 ohm antenna
feed points to 75 ohm (or
52 ohm) cable with corresponding extra connection points. With VHF/UHF
antennas, such baluns typically
causes 1.5 dB to 6 dB insertion losses with UHF signals, attenuating a major
portion of the typical 4 dB
to 8 dB UHF antenna gain.
[0007] Cable loss: Even using quality RG-6 75 Ohm coax cable, high UHF signals
are often
attenuated within the connecting cable by 50% to 75% or more of the signal
gain obtained by high gain
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CA 02604405 2007-11-01
antenna. E.g., the FCC (2005) expects signal attenuation of about 4 dB for a
15 m (50 ft) downlink for 470-
800 MHz (Channels 14-69) signal in RG-6 coax cable compared to an 8 dB gain
using a good Yagi UHF
antenna.
[0008] Increased Transmission: Digital TV transmission is often increased to
1,000 kW or more
to accommodate higher losses and minimum S/N reception requirements. Relevant
art antenna amplifiers
(or "preamps") configured for 50 kW transmission often saturate and distort
("splatter") when receiving
such stronger DTV TV transmissions. This can cause digital signal dropout,
especially near high power TV
transmitters.
100091 Generic performance: Increasing propagation distances and signal
degrading environments
are commonly categorized as "Urban, "Suburban", "Far Suburban", "Mid Fringe"
and "Deep Fringe"
reception regions. Generic broadband antenna systems are typically
unnecessarily expensive if used near
to transmitters in Urban and even Suburban areas. Yet they may be marginal in
Mid Fringe areas and are
often unusable in Deep Fringe areas.
[0010] Complex: Numerous antenna systems are complex and difficult to install
with confusing
instructions. E.g., one prior art high gain VHF/UHF antenna shown in FIG. 23
(see US Patent 3,531,805).
As further depicted in that prior art, VHF antenna supports often use highly
complex VHF elements with
numerous mounting components and phasing lines. These have numerous contacts
and mounts that are
prone to corrosion, wear and failure. Long elements are often folded for
shipping and users frequently do
not unfold elements. FIG. 24 shows the corresponding short 168 mm (6.63")
prior art "Peterson" folded
VHF/UHF driven dipole element. Such relevant art UHF designs are no longer
optimized for UHF DTV
signals.
[0011] Low VHF/UHF reception: The US Federal Communications Commission (Dec.
2005
Report 05-199) plans on antennas with 6 dB gain for the VHF High Band with a
Front/Back ratio of 12 dB
for distant DTV signals in "Fringe" areas. This FCC (2005) report plans on 10
dB gain for the UHF band
with a Front/Back ratio of 14 dB. The conventional art uses large VHF antennas
to achieve such VHF
performance, especially for fringe regions. Most UHF antennas marketed for the
Digital TV exhibit very
low VHF gain. UHF enhancing screens of relevant art high gain UHF antennas
show low VHF reception.
Similarly a good UHF Yagi antenna while providing modest UHF gain, provides
very little VHF reception.
Many antennas advertised for VHF/UHF reception are described by third party
evaluators as exhibiting
marginal performance in the UHF range and very poor performance in the VHF
range.
[0012] Low Signal/Noise Ratios: Analog TV or NTSC transmission, results in
progressively
degraded and increasingly fuzzier reception with increasing distance,
intervening vegetation, and/or
multipath signal transmission. While degraded, analog audio can often still be
understood. However,
amplifying signals with low antenna gain and/or long lossy lines degrades
signal/noise ratios. This can
cause instability or total dropout with both video and audio reception of DTV
signals.
[0013] Physical Unattractiveness: Most high performance broadband VHF/UHF
antennas have
large obtrusive Log periodic structures or numerous bowtie elements with large
screens. Small unobtrusive
antennas give poor performance, especially in the VHF High Band range.
[0014] Wind loading: Relevant art antennas typically use box channel or
cylindrical VHF
elements resulting in substantial wind loading and wear.
Objects and Advantages
[0015] Some of the major objects and advantages of the invention are as
follows:
[0016] Configure broadband antennas for Digital TV UHF and/or VHF High Band
ranges.
[0017] Configure antennas for the Digital FM ranges.
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100181 Configure antennas for "mid fringe" regions up to 72 km to 80 km (45 to
50 miles) from
transmitters.
100191 Provide compact unobtrusive antennas.
100201 Reduce wind induced antenna flexure and wear.
100211 Transmit the received or transmission signal without major signal loss.
[0022] Transmit received signals without major degradation in signal to noise
ratio.
[0023] Configure electrical connections to minimize or eliminate contact
corrosion losses.
[0024] Configure electrical connections to minimize contact flexure wear and
signal loss.
100251 Provide efficient transfer of RF signals between the driven dipole and
feed line.
[0026] Provide efficient transfer of RF signals between the feed line and a
signal connector.
[0027] Reduce impact of solar, wind and lightning environmental conditions.
100281 Provide a light weight simply constructed but highly durable antenna.
100291 Provide very easy installation with simple instructions.
[0030] Eliminate most assembly and related errors.
Summary of the Invention
10031] A Digital UHF/VHF (DUV) antenna and configuration method are provided
for the Radio
Frequency (RF) range, especiallythe Ultra High Frequency (UHF) and Very High
Frequency (VHF) ranges.
Preferred embodiments are configured for the digital TV UHF DTV (Channels 14 -
51), the VHF High
Band (Channels 7-13), and/or the Digital FM range. One unexpected development
was obtaining
substantial VHF High Band performance while retaining strong UHF DTV
performance in some
lightweight embodiments. E.g., by configuring a wideband driven DUV element or
DUV antenna
optionally boosted by multiple passive UHF enhancers, VHF enhancers and/or
reflective RF boosters. The
driven DUV antenna (or dipole) and RF enhancer(s) are supported by an antenna
support which may
comprise one or more of a DUV housing, a longitudinal boom, a boom-mast mount,
an antenna mast, a
mast-structure mount, a director boom, an off axis booster boom, a booster
mount, intra antenna boom, a
support spar and an offset. Such configurations form efficient lightweight DUV
antennas - without the very
large VHF log-periodic elements or numerous bowtie dipoles, screens and
corresponding complex
corrosion prone connections commonly used.
100321 The driven DUV antenna preferably comprises wideband DUV elements
configured to
resonate in one and more preferably in both a prescribed UHF range and a
prescribed VHF range. E.g.,
within 30 MHz to 300 MHz in the VHF and 300 MHz to 3000 MHz in the UHF and
preferably within the
VHF High Band range of 170 MHz to 220 MHz, and UHF range of 470 MHz to 800
MHz. It may be
configured to resonate near or in the FM band. (e.g., 88 MHz to 108 MHz). DUV
antennas are more
preferably configured for three halves wave resonance in the DTV UHF range and
for half wave resonance
near or in the VHF range. E.g., a wideband DTV DUV antenna is more preferably
configured for half wave
dipole resonance near or in the VHF High band from 170 MHz to 220 MHz while
obtaining three halves
resonance from about 510 MHz to 660 MHz within the DTV UHF band.
[0033] DUV antennas may further be configured for specialized ranges. For
example, in one
configuration a U-DUV dipole may be configured for half wave resonance near
the top or above the VHF
High band giving three halves resonance in the UHF band. E.g., halfwave
resonance above about 220 MHz
giving three halves resonance above about 660 MHz. In one configuration, the U-
DUV-230 UHF dipole
is preferably configured for half wave resonance near about 230 MHz giving
three halves resonance about
690 MHz near the upper end of the UHF DTV band (near 686 to 692 MHz for DTV
Channel 51).
Similarly, a medium M-DUV-213 dipole embodiment may be configured near the
upper end of the VHF
High Band for half wave resonance about 210-216 MHz (DTV Channel 13) and three
halves UHF
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resonance about 630 to 648 MHz (near Channels 41-43). DUV dipoles may
similarly be configured for
broadband coverage of the 700 to 800 MHz range.
[0034] In further configurations, the driven DUV antenna or DUV dipole is
preferably configured
for five eighths resonance in the VHF band while providing three halves
resonance in the UHF band. E.g.,
a V-DUV-170 dipole may be configured for half wave resonance about 170 MHz
near the bottom of the
VHF High Band range (near DTV Channel 7). This beneficially provides five
eighths resonance at about
213 MHz in the upper end of the VHF High Band as well as three halves UHF
resonance about 510 MHz.
In another configuration, a V-DUV- 157 dipole is preferably configured for
five eighths resonance near the
middle of the VHF High Band at about 196 MHz, and three halves resonance near
the bottom of the UHF
band about 470 MHz (with nominal half wave resonance about 157 MHz).
[0035] Similarly an F-DUV antenna may be configured for half wave resonance in
or near the FM
range (e.g., the VHF range of 88 MHz to 108 MHz.) Further examples of such DUV
antenna configura-
tions are shown in Table 1. Multiple specialized DUV dipoles or DUV antennas
are preferably used to
further improve reception in the UHF and VHF bands respectively in some
embodiments. Generalizing,
the driven antenna is preferably configured for a first odd to even rational
number wave resonance in the
prescribed UHF range, and for a second odd to even rational number wave
resonance in the prescribed VHF
range. These odd to even rational numbers preferably consist of an odd integer
divided by an even integer.
E.g., a rational number selected from one quarter, three eighths, one half,
five eighths, three quarters, seven
eighths, five quarters and three halves.
[0036] A Radio Frequency (RF) amplifier is preferably added to and close
coupled with one or
more RF contacts ofthe driven DUV element and/or DUV dipole to improve the
amplitude and/or preserve
the signal/noise ratio ofthe transmitted signal. The RF contacts ofthe DUV
elements, the RF amplifier and
the signal connector are preferably electrically bonded together with suitable
lengths of high quality RF
signal line. A RF fiber optic link between the RF amplifier and the signal
connector is more preferably used
to communicate the RF signal with minimal signal degradation and to preserve
the amplified DUV
antenna's high signal/noise ratio.
[0037] One or more RF enhancement elements supported by the antenna support
are preferably
added in some antenna configurations. These may comprise one or more of a UHF
enhancement element
comprising one of a UHF director element and a UHF reflector element, a VHF
enhancement element
comprising one of a VHF director element, and a VHF reflector element, and an
RF booster comprising
multiple reflective elements configured off of the longitudinal axis to
reflect signals to/from the driven
dipole. The director and/or reflector elements are preferably passive
("parasitic") elements mounted on the
longitudinal boom. The reflective elements of the RF booster are preferably
mounted on one or more
booster booms supported by the longitudinal boom. These RF enhancements are
preferably provided
without RF VHF connections to the DUV dipole or RF amplifier.
[0038] Shorter UHF RF booster reflective elements are preferably configured
above and below
a longitudinal boom with a gap between the innermost reflective lower elements
to enhance VHF reflection
by a VHF reflector behind the DUV dipole. Longer VHF RF booster reflective
elements preferably include
a UHF reflector behind the DUV dipole to enhance the UHF performance. These
.RF booster configurations
provide substantially improved VHF high band signal gain while retaining good
UHF signal gain in a
compact configuration.
[0039] UHF and/or VHF enhancement elements are preferably streamlined to
reduce wind
loading. DUV antennas are usually sufficiently compact to be shipped
preassembled or with modest
assembly. They preferably use bonded RF connections leaving just a few RF
signal connections. More
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preferably inner RF connections on a DUV element or multiple DUV elements
forming one or more DUV
dipoles are RF communicatively connected to an RF signal line using bonded
connections with only one
signal connector at the end of the signal line. Multiple UHF and/or VHF DUV
dipole antennas may be
provided and/or stacked to further improve signal gain.
100401 In some embodiments, a protective housing is preferably configured
around the RF
amplifier and the DUV dipole's RF contacts. The signal connectors are usually
provided with environmen-
tal seals. The inner DUV dipole mounts, amplifier, and associated signal line
contacts are preferably
hermetically covered by epoxy or potting to protect against corrosive
components such as water, improve
strength, and increase reliability. In some configurations, the housing
surface and composition are
configured to reduce solar heat gain, RF reflection, and/or multipath signals.
A lightning rod may be added
to reduce lightning strike hazzards.
100411 DUV antennas are preferably mounted with a biconvex mount provides
three degrees of
freedom. Besides pointing the antenna azimuthally to obtain the best
reception/transmission mix, the DUV
antenna is preferably rotated about the antenna support's longitudinal
pointing axis to orient the antenna
within 75% and 125% of the local signal's maximum polarization or desired
polarization. The DUV
antenna is preferably configured vertically to position the driven antenna
within one or more moire fringe
RF signal maximums.
100421 Such DUV antenna configurations eliminate almost all problems with
multiple RF
connections, connection wear, corrosion, and the associated signal losses.
They provide consumers with
a very simple signal connection. The DUV antennas are compact and relatively
unobtrusive while giving
very good performance from Metro to Fringe DTV regions. DUV antennas are
configured for simplicity
in assembly, eliminating most potential user assembly errors.
Brief Description of the Drawings
[0043] Having thus summarized the general nature of the invention and some of
its features and
advantages, certain preferred embodiments and modifications thereof will
become apparent to those skilled
in the art from the detailed description herein having reference to the
figures that follow, each having
features and advantages in accordance with one embodiment of the invention,
namely:
List of Drawings
FIG. I Perspective view of a Digital UHF/VHF (DUV) antenna.
FIG. 2 Exploded view of a DUV dipole and amplifier.
FIG. 3 Perspective view of a perforated DUV Fan Element
FIG. 4 Closeup of RF conductive elements on perforated DUV Fan.
FIG. 5 Single DUV Element Support of folded elongated elements.
FIG. 6 Dual DUV support of folded elongated elements.
FIG. 7 A U Mount DUV dipole around a support boom in schematic elevation.
FIG. 8 A Top Mount DUV dipole above a support boom in schematic elevation.
FIG. 9 A DUV Aster dipole in schematic elevation.
FIG. 10 A DUV Accordion dipole in schematic elevation.
FIG. 11 A dual DUV Loop dipole in schematic elevation.
FIG. 12 A VHF & UHF enhanced DUV antenna in schematic perspective.
FIG. 13 A UV-DUV Antenna with M-DUV and V-DUV dipoles in schematic
perspective.
FIG. 14 Two axis rotatable Antenna Mount with lightning rod in perspective.
FIG. 15 A Triple UVU-DUV Antenna in schematic perspective.
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FIG. 16 A curved RF Booster with four streamlined elements.
FIG. 17 A 5-DUV Antenna in schematic perspective.
FIG. 18 "Fringe" DUV-Antenna in rear perspective.
FIG. 19 Tapered folded Reflector element in perspective.
FIG. 20 Tapered folded Booster Reflector element in perspective.
FIG. 21 Tapered Conical Streamlined Reflector element.
FIG. 22A Amplifier housing.
FIG. 22B Amplifier housing wall detail.
FIG. 23 A Prior Art high gain VHF & UHF antenna.
FIG. 24 A Prior Art folded dipole element.
100441 Tables, Components and Parameters
[0045] Table 1 DUV Element configurations
100461 dB Signal strengths in dB listed herein are referenced to dBd (to an
equivalent dipole
receiver, not dBi referenced to an isotropic receiver. For dBi, add 2.15 dB to
convert dBd to dBi.)
[0047] LD Electrical tip to tip length of DUV dipole.
[0048] LE Electrical tip to contact length of DUV element.
[0049] LC Contact to contact length between DUV elements
[0050] LV Electrical tip to tip length of VHF reflector.
[0051] HE Maximum electrical height of DUV element
[0052] RHL Ratio of Height of Element HE to Length of Element LE
[0053] References: Federal Communications Commission "Study Of Digital
Television Field
Strength Standards And Testing Procedures" ET Docket No. 05-182, December 9,
2005, Report: FCC 05-
199.
Detailed Description
[0054] DUV Antenna: With reference to FIG. 1, in one embodiment of the
invention, a DUV
antenna 2 comprises a driven DUV element 21 configured to be driven by a
Digital UHF VHF (DUV)
signal. E.g., the DUV element is preferably configured to be driven by a
digital television (DTV) signal,
radio signal, or internet signal, having a frequency within one of the UHF
range of about 300 MHz to 3
GHz, and/or within the VHF range of about 30 MHz to 300 MHz. The DUV antenna 2
preferably
comprises two DUV elements 21 collectively forming a DUV dipole 20. The DUV
dipole is preferably
configured for the Digital TV and/or digital FM range from about 55 MHz to 801
MHz. Inner RF contacts
of DUV elements 21 are RF communicatively connected to a RF feed or signal
line 260. DUV antenna 2
comprises an antenna support supporting driven DUV antenna 20, and an RF
signal line or cable 260 RF
communicatively connected to the DUV element 21 or DUV dipole 20. The antenna
support preferably
comprises a longitudinal boom 102 connected to mast 150 by boom-mast mount
152.
[0055] VHF Reflector: Further referring to FIG. 1, the VHF reception of the
DUV antenna 2 is
preferably enhanced or boosted by providing a passive VHF reflector 82
configured generally parallel to
the DUV element 21 or DUV dipole 20. It is usually mounted on and generally
perpendicular to a
longitudinal boom 102. Longitudinal boom 102 is usually mounted with a boom-
mast mount 152 to a mast
150. E.g., a U-Bolt type mount. For ease of description, consider a reference
system positioned with a
forward pointing axis or X axis is positioned along the axis bisecting and
perpendicular to the major DUV
dipole plane, usually parallel to and above the longitudinal boom 102,
pointing to the antenna "Front' ,
("director" end), and away from the "Back", ("reflector end"). The YZ plane is
nominally aligned with the
major DUV dipole plane, with the Y axis along the DUV dipole's major axis, and
the Z axis along the
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DUV dipole's minor axis. (The DUV dipole may be symmetric about the Y and X
axes.) Such VHF
reflectors 82 generally improve the VHF gain by about 2-3 dB. A second
reflector may add another 0.5 dB.
VHF reflector 82 further improves the UHF FrontlBack ratio, beneficially
reducing UHF multipath
reception. The VHF reflector 82 is preferably streamlined along the X axis to
reduce wind loading.
[0056] The electrical length LV of the VHF reflector 82 is preferably resonant
in the VHF range
with the length depending on the antenna reception range desired. E.g., LV is
generally from about 660 mm
(26 in) to about 915 mm (36 in) electrical resonant length for 9.5 mm (0.375
in) diameter elements. The
VHF reflector is more preferably configured for the middle to lower end of the
VHF High Band where it
is generally more difficult to receive desired channels. E.g., in one
configuration, the length LV of the VHF
reflector 82 is about 732 mm (28.8 in) for a frequency of about 195 MHz (US
digital channe110) near the
middle ofthe VHF High Band. In another configuration the VHF reflector 82
length LV is preferably about
806 mm (31.7") long for 9.5 mm (0.375 in) diameter elements. This beneficially
enhances reception near
177 MHz (US channel 7) near the bottom of the VHF high band. In a further
configuration, the length LV
may be configured longer with about 864 mm (34 in) for resonance of about 149
MHz to improve VHF
high and low band reception.
[0057] VHF reflector position: Further referring to FIG. 1, the VHF reflector
82 is positioned
towards the "Back" along the negative X axis behind the DUV dipole. E.g.,
reflector 82 is preferably
positioned behind the DUV dipole about 30% to 55% of the electrical length LV
of the VHF reflector
element 82 in some configurations. It is preferably located at about 40% of LV
along the negative X axis.
This beneficially improves reception around the upper end of the US VHF High
Band. E.g., In
configurations with a reflector length LV of about 864 mm (34 in), the VHF
reflector 82 may be located
about 298 mm (11.75 in) to 406 mm (16 in) behind the DUV dipole 20 in the
negative X direction. It is
preferably located between about 324 mm (12.75 in) and 381 mm (15.0 in), and
more preferably at about
349 mm (13.75 in) from the DUV dipole 20.
[0058] RF UHF/VHF Booster: With further reference to FIG. 1, in some
embodiments, the UHF
and VHF reception of the DUV antenna is preferably enhanced by positioning one
and usually two
UHF/VHF enhancers or RF boosters 110 near the DUV elements 21 and displaced
above and/or below the
XY plane. These RF boosters 110 comprise one and preferably a plurality of
booster reflector elements 62
configured about parallel to the Y axis or the DUV element 21 axis. The
booster reflector elements 62 are
preferably mounted on one or more UHF/VHF enhancer supports or booster booms
122. The booster
booms 122 may be bonded to or mounted on the longitudinal boom 102. Booster
booms 122 are preferably
mounted on a UHF booster mount 120 on the longitudinal boom 102.
[0059] Removing central booster reflector elements: To enhance VHF signals,
the RF boosters
110 are preferably configured with a space above and below the X axis,
sufficient to permit VHF signals
to propagate to and be reflected off of the VHF reflector element 82. E.g., in
some configurations, the
reflector element nearest the longitudinal axis of a conventional UHF corner
reflector is removed from both
the upper and lower booms. Removing these elements reduced the UHF gain and
UHF Front/Back ratio
by about 2 dB. However, displacing the closest reflector elements 62 from the
longitudinal X axis by more
than the reflector to reflector distance provides a very substantial and
unexpected improvement of the VHF
signal in comparison to conventional UHF "corner reflectors". E.g., this
unexpectedly increases the VHF
gain by 2-3 dB in the lower VHF High Band near channel 7, and by about 3-4 dB
in the upper VHF High
Band near Channel 12.
[0060] For example, in one configuration shown in FIG. 1, the reflector
elements of a
conventional "corner reflector" closest to the longitudinal axis were removed
to form an RF booster 110.
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Two UHF reflector elements 62 on each RF booster 110 were used above and below
the longitudinal boom.
E.g., in one configuration, the inner reflector elements were spaced at about
135 mm (5.3") from the
longitudinal boom, and the outer reflectors at about 224 mm (8.8") from the
longitudinal boom, and about
102 mm (4 in) and 13 mm (0.5 in) along the negative X axis from the DUV
dipole.
100611 RF Booster Configurations: Referring to FIG. 1, each booster boom 122
maybe configured
at an angle from about 30 deg to 80 deg to the longitudinal boom or X axis. It
is preferably from 50 to 70
deg, and more preferably about 60 deg. In this configuration, the booster
elements are positioned about
symmetrically above and below the DUV dipole or the XY plane near the top of
the longitudinal boom 102.
In this configuration, RF boosters 110 are pivoted on booster mount 120 about
29 mm (11/8 in) above and
below the XY plane about 119 mm (4 11/16 in) behind the DUV dipole. In some
configurations, the
booster boom angle with the longitudinal boom may be reduced to increase UHF
gain while reducing the
VHF gain, and vice versa. Mount 120 may be asymmetric to position boosters
symmetrically about the XY
plane in line with DUV dipole and reflector elements mounted on top of boom
120. Mount 120 is
preferably symmetric to reduce costs.
[0062] Curved Booster Mounts: Referring to FIG. 16, in one embodiment, a
curved UHF/VHF
RF booster 122 is preferably formed by mounting multiple reflector elements 85
on a curved boom 116
positioned around the DUV dipole 20 in some embodiments. Reflector elements 85
are preferably
streamlined in the horizontal plane, and more preferably tapered a wide depth
at the center to a low depth
at the outer tip. They may be bonded to the curved boom 116, or mounted onto
the boom with a fastener,
optionally located through a mounting hole 71. One or two curved booms 116 are
preferably formed into
parabolic curves and configured like a forward pointing Winston or compound
parabolic collectorto reflect
the RF signal to/from the DUV dipole 20. E.g., a first curved boom 116
configured about like a parabola
with a first focus Fl is mounted with its axis Al about at an angle RI to the
longitudinal boom 102. A
second curved boom 116 with a second focus F2 is mounted with its axis A2
about at an angle R2 to the
longitudinal boom 102.
[0063] The first curved boom 116 nominally touches the second focus F2, and
the second boom
116 touching the first focus F 1. These are configured so that the DUV dipole
20 is positioned about on the
plane about midway between the two foci F 1 and F2. The angles Rl and R2 are
preferably in the range of
deg to 75 deg, more preferably in the range of 10 deg to 50 deg and more
preferably still within about 20
to 30 deg. Referring to FIG. 1, in some configurations, this curved boom
configuration may be
approximated by mounting one ortwo UHF reflector elements nearest the axis on
the inner sides of straight
booster booms 122 nearest the DUV dipole 20, while mounting reflective
elements 62 further away from
the longitudinal support on the outer sides of the booster booms 122 away from
the DUV dipole 20.
[0064] UHF Enhancer: Further referring to FIG. 1, the UHF reception of the DUV
dipole 20 is
preferably boosted by mounting a plurality of passive RF conductive RF or UHF
director elements 50 on
the longitudinal boom 102 about parallel to the Y axis and displaced from the
DUV dipole 20 towards the
"Front" along the positive X axis. The director elements 50 are preferably
streamlined to give a low profile
in the YZ plane relative to wind in the X direction to reduce horizontal wind
loading. The director elements
50 are preferably bonded to the longitudinal boom 102. E.g., by welding,
brazing or soldering, such as with
a fiber laser, or by adhesive bonding. This beneficially improves durability
and reduces cost. The director
elements 50 may also be crimped on, or mounted using a fastener such as a
rivet, screw or bolt. In some
configurations, the RF director elements 50 arepreferably about 190 mm (7.5")
long, and spaced about 100
mm (4") apart, starting about 50 mm (2") from the DUV element 21. E.g., for 13
mm (0.5 in) wide
stampings, or 9.5 mm (0.38 in) diameter cylindrical elements.
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[0065] DUV Element: With reference to FIG. 3, a DUV antenna may comprise one
driven DUV
element 21 configured to be driven by a digital electromagnetic signal in at
least one of the UHF and the
VHF range. The driven DUV element 21 is typically driven by impinging radio
frequency (RF)
electromagnetic wave. The DUV element 21 may also be driven by an
electromagnetic signal from a
conductively, capacitatively, inductively, or optically coupled feed or signal
line 260. DUV element 21 is
preferably configured to be driven in the DTV or DFM range of about 55 MHz to
801 MHz. More
preferably, the DUV element is configured to be driven by a digital television
signal in one of the VHF
High band range (e.g., 170 MHz to 220 MHz), and the UHF range (e.g., 470 MHz
to 698 MHz).
100661 With reference to FIG. 3, each DUV element 21 is preferably configured
within a height
HE to length LE ratio RHL of DUV element 21 of between about 0.01 and 10. DUV
elements 21 are
preferably configured with their height to length ratio RHL between about 0.1
and 1.0, and more preferably
between 0.2 and 0.6. e.g., in one configuration, DUV element 21 was preferably
configured with a flat
width of 168 mm (6.63 in) folded to a height of about 101 mm (4 in) and with a
length of about 251 mm
(9.9 in), giving a ratio RHL of Height/Length of about 0.40. The ratio of
folded elevation area to unfolded
elevation area is preferably between 0.2 and 0,75, and more preferably about
0.6.
[0067] DUV Dipole Antenna: With reference to FIG. 2, in one embodiment, the
DUV dipole 20
may comprise two driven DUV elements 21 configured in the YZ plane about
perpendicular to the
longitudinal boom 102 and X-axis. The RF signal line 260 with DUV element 21
or DUV dipole 20
(comprising two DUV elements) collectively form a driven DUV antenna 12. DUV
elements 21 are
usually similar and mirrored about the XZ plane. They are generally similar
and mirrored about the XY
plane. However, in some configurations they may be different and/or asymmetric
about the X and/or Y
axes. In FIG. 2, the DUV elements are nominally shown oriented to the left (L)
and right (R) of the X axis
pointing to the antenna's "Front." The RF contacts 44 of the DUV element 21 or
dipole 20 are RF
communicatively connected to the RF signal line 260. In some embodiments,
driven DUV antenna 12
preferably comprises an RF DUV amplifier 202 with signal contacts connected to
signal line 260, RF
contacts 236 connected to element RF contacts 44, preferably using element
leads 290.
[0068] The DUV dipole is preferably configured for half wave resonance in the
VHF High Band
(e.g., 174 MHz to 216 MHz) while being configured for three halves resonance
in the middle portion of
the DTV UHF band (e.g., 522 MHz to 648 MHz). More preferably, the DUV dipole
20 is configured for
one half wave resonance near the middle to upper end of the VHF high band
(e.g., about 192 MHz - 216
MHz) and correspondingly configured for thee halves wave resonance in the
respective DTV UHF band
(e.g., 576 MHz to 648 MHz). This beneficially retains the very important high
UHF gain while increasing
VHF High band gain. With wide DUV elements, the element electrical lengths LE
may be configured
assuming a dipole end effect for the DUV dipole of about 0.7 similar to wide
bowtie antennas. Compared
to prior art antenna elements configured for the upper end of the UHF band
(such as shown in FIG. 24),
such driven DUV antennas or dipoles beneficially provide major antenna VHF
High Band gain while
retaining very good DTV UHF band gain.
[0069] DUV Configuration: Referring to FIG. 3, the driven DUV element 21
comprises a radio
frequency (RF) conductive component 40 that is part of andlor supported by a
structural component 30.
The DUV element 21 is preferably designed to survive design peak wind
conditions and gravity. Each DUV
element 21 comprises a structural element 30 extending outward from a DUV
dipole element support 38
near an inner end 99 near the DUV antenna longitudinal axis X, to an outer end
98 away from the DUV
antenna axis X. The structural element 30 is preferably positioned generally
in the YZ plane about
perpendicular to the DUV antenna axis X. Referring to FIG. 2, the DUV antenna
preferably comprises a
9
CA 02604405 2007-11-01
plurality of DUV elements configured as one or more DUV dipoles 20 with an
overall electrical resonant
length LD. e.g., as DUV elements 21 positioned left and right of the antenna
axis X.
[0070] RF Conductive Elements: Referring to FIG. 2, each DUV element 21
comprises an RF
conductive element 40 extending from near the inner end 99 to about the outer
end 98 of the DUV element
21. The RF conductive element 40 comprises a conductive RF contact 44,
preferably configured near the
inner end 99 ofthe DUV element. With reference to FIG. 3, FIG. 4 and FIG. 5,
in some configurations, the
DUV elements have perforations or holes. E.g., to reduce wind loading. In such
configurations, the RF
conductive element preferably comprises at least two RF elongated conductive
elements 42 extending from
near the inner end of the DUV element 99 to near the outer end 98 of the DUV
element.
[0071] Element Length: In some configurations, the electrical length LE of DUV
elements 21
(together with half the contact to contact distance LC) is preferably
configured for half wave dipole
resonance about in the VHF High Band and for three halves resonance in the UHF
DTV range. (e.g., about
470 MHz to 698 MHz). LE is measured from about the DUV element RF contact 44
near the inner end 99
to near the outer conductive tip 98. To resonate at or near a prescribed
frequency, thin driven dipoles 20
are typically configured using dipole end effect of about 91% to accommodate
the dipole end effect. (i.e.,
the factor to multiply the theoretical dipole to obtain actual resonance).
Referring to FIG. 2 and FIG. 3,
DUV fan elements with length LE typically require lower dipole end effect
factors. E.g., using dipole end
effect of about 70% of the theoretical dipole element for the desired resonant
wavelength.
100721 In some embodiments, a broadband DTV UHF/VHF DUV dipole is configured
with
element lengths LE from about 218 mm to 302 mm (8.6 in to about 11.9 in). The
DUV dipole is preferably
configured with DUV element lengths LE of about 249 mm to 254 mm (9.75 to 10
in) with about a 32 mm
(1.25") center contact to contact distance. This gives an overall physical tip
to tip DUV dipole length LD
of about 527 to 540 mm (20.75 to 21.25 in). E.g., such a DUV dipole with 249
mm (9.75") long elements
(and an LC of 32 mm) gave a 3 dB higher performance in the VHF high band than
an equivalent dipole
with the same length elements made of 13 mm (0.5") diameter conductive rod
(e.g., copper). This DUV
dipole gave 1.5 to 2.2 dB higher gain than the rod dipole across the DTV UHF
range.
[0073] A shorter U-DUV dipole is preferably used in some configurations. E.g.,
with UHF three
halves resonance about from 660 MHz to 860 MHz, with VHF half wave resonance
above about 220 MHz.
U-DUV elements may have lengths LE from about 172 mm to 218 mm (6.8 in to 8.6
in) long. Such lengths
enhance higher UHF reception with some reduction in VHF reception. Other
configurations may use V-
DUV dipoles preferably using longer DUV elements lengths. E.g., using V-DUV
elements with an
electrical lengths LE of about 267 mm to 330 mm (10.5 in to 13 in) long. This
beneficially enhances VHF
reception while still having good UHF reception. In further configurations, an
X-DUV extended dipole is
used with a longer electrical length. E.g., the X-DUV element electrical
lengths LE may be about 330 mm
to 508 mm (13 in to 20 in) from outer end to contact, and preferably about 356
mm (14 in). This larger X-
DUV dipole beneficially enhances both VHF reception and UHF reception above
the broadband DUV
dipole.
[0074] Table I DUV Element configurations
Length End Resonant Frequencies
Model Factor L/2 5L/8 3L/2
mm in MHz MHz MHz
U-DUV-300 159 6.3 0.7 300 375 900
U-DUV-290 165 6.5 0.7 290 363 870
U-DUV-280 172 6.8 0.7 280 350 840
U-DUV-270 178 7.0 0.7 270 338 810
CA 02604405 2007-11-01
U-DUV-260 186 7.3 0.7 260 325 780
U-DUV-250 194 7.6 0.7 250 313 750
U-DUV-240 203 8.0 0.7 240 300 720
U-DUV-233 210 8.3 0.7 233 291 698
U-DUV-230 212 8.4 0.7 230 288 690
M-DUV-220 223 8.8 0.7 220 275 660
M-DUV-210 234 9.2 0.7 210 263 630
M-DUV-200 246 9.7 0.7 200 250 600
M-DUV-190 260 10.2 0.7 190 238 570
V-DUV-180 276 10.9 0.7 180 225 540
V-DUV-170 293 11.5 0.7 170 213 510
V-DUV-160 312 12.3 0.7 160 200 480
V-DUV-157 335 13.2 0.7 157 196 470
X-DUV-150 334 13.1 0.7 150 188 450
X-DUV-140 359 14.1 0.7 140 175 420
X-DUV-120 421 16.6 0.7 120 150 360
X-DUV-100 509 20.0 0.7 100 125 300
X-DUV-80 640 25.2 0.7 80 100 240
@ Length LC = 31.8 1.25
[0075] Further examples of DUV element configurations are shown in Table 1.
These assume an
element contact to contact spacing LC of 32 mm (1.25 in). Center to center
distance LC may vary from 13
mm to 75 mm (0.5 in to 3 in) with the same tip to tip length LD. These DUV
element configurations are
shown for nominal half wave resonance frequencies MHz assuming a dipole end
effect factor of about 0.7.
The corresponding nominal three halfwave resonance is shown along with the
five eighths wave resonance.
Resonant frequencies within or near UHF DTV band and VHF High band are
underlined.
100761 The RF contact 44 preferably covers a portion of at least one surface
of the element
support 38, and more preferably covering at least a portion of the element
support surface about the mount
hole 220. The RF conductive elements and structural elements are preferably
formed together with the RF
contact 44 positioned against corresponding support RF contact.
[0077] To reduce wind loading and/or weight, the DUV elements are preferably
formed from a
sheet of RF conductive perforated metal or bonded wire mesh comprising
perforations openings 34. Here
sequences of metal between perforations or openings 34 in effect form the RF
elongated conductive
elements 42 extending outward from the inner end 99. The DUV elements 21 are
more preferably formed
from a composite of an RF conductive element 40 bonded to a structural element
30. E.g., a mechanically
or electrically applied conductive layer 40 formed on or within a fiber
reinforced material, or a plastic layer
30.
[0078] Element Supports: With reference to FIG. 2, in some embodiments each
DUV element
21 preferably comprises at least one and more preferably at least two element
supports 38 with which to
support the DUV element. (See also FIG. 3, FIG. 5 and FIG. 6.) The element
support 38 is preferably
configured near the inner end 99 of the DUV element towards the antenna axis
X. An element mount hole
220 is preferably formed in at least one and more preferably in at least two
of the element supports 38.
Structural attachment tabs, or enlarged ends may similarly be used to provide
a sturdy attachment.
100791 DUV Fan: Referencing FIG. 2 and FIG. 3, in some configurations, the DUV
structural
element preferably comprises a triality of three or more stiffening portions,
bends or undulations displaced
out of a mean YZ plane through the element. More preferably, the DUV element
21 is configured as a DUV
Fan 90 wherein the structural component comprises at least three stiffening
portions, or folds 31 between
11
CA 02604405 2007-11-01
at least four elongated element portions 32. More preferably, the DUV Fan 90
comprises seven or more
folds 31 between eight or more elongated element portions 32.
100801 The elongated element portions 32 may be formed from trapezoidal
segments as shown
in FIG. 2. The elongated portions 32 are preferably configured as rectangular
segments as shown in FIG.
3. The maximum width WP of the elongated element portions 32 may be between 2%
and 75%, and
preferably between 5% and 20% of the height HE of the DUV structural element.
More preferably, with
eight to ten elongated portions 32, their width WP is between about 15% and 8%
of the DUV element
height HE.
[0081] Folded Supports: With reference to FIG. 4 and FIG. 5, in some DUV Fan
configurations,
one element support 38 is preferably formed by folding together and more
preferably bonding together at
least two elongated element portions 32. E.g., a folded support formed
preferably in the XY plane. As
depicted in FIG. 3 and FIG. 6, DUV Fan configurations more preferably comprise
an element support 38
formed from at least three elongated element portions 32. Such folded supports
38 beneficially provide
improved bending structural support for thin extended materials against both
wind and gravity. In other
configurations, the folds 31 may be shallower with angles from 5 deg to 85 deg
from the XY plane.
[0082] Element Stiffener: With reference to FIG. 6, in some configurations,
the inner portion of
one or more elongated element portions is preferably folded and/or cut
sufficiently to form an element
stiffener 37 generally perpendicular to the one or more element supports 38.
The element stiffener 37 is
preferably offset from the element mount hole 220 far enough along the DUV
antenna longitudinal axis
X to facilitate fastening at least one DUV element support 38 to a DUV element
mount. (The element
stiffener may also be folded out of the way as desired.) The element stiffener
37 beneficially adds bending
stiffness about the Z axis.
[0083] Element End Tips/Recess: With reference to FIG. 2, in some
configurations, the outer
portion of the DUV element or DUV Fan may be cut back by between 2% and 60%
from the outer end 98
towards the inner end 99 to form an element end tip 39. The recess is
preferably near the center to form
multiple tips 39 towards the upper and lower element ends. Alternatively, one
or more upper and/or lower
portions may be recessed. Preferably, the element is cut back between 4% and
60% of the element length
over portion of its height. More preferably between 10% and 30% of the element
length. This cutback 39
forms a central notch (or one or two outer notches). It beneficially reduces
wind loading.
[0084] Element Perforations: With reference to Fig. 3, the DUV element 21 is
preferably
comprises numerous openings or perforations 34 from near the element support
to near the outer end of the
DUV element. The perforations are preferably circular or elliptical, but may
comprise slots, trapezoids,
or other non-elliptical perforations. The non-perforated area of the DUV
element is preferably reduced to
between 20% and 80% of the DUV element's outer elevation area projected onto a
vertical surface in the
YZ plane parallel to the DUV element. More preferably, the non-perforated area
of the DUV element is
reduced to between 50% and 70% of the element's projected area. With reference
to FIG. 4, in one
configuration, the perforations 34 are preferably formed within the elongated
element portions 32 and not
within the adjacent fold 31. The perforated structural elements beneficially
reduce the wind loading on the
DUV Elements, increasing the antenna durability and/or reducing its cost. With
reference to FIG. 7, one
or more sizeable portions of the DUV element may be removed to similarly
reduce wind loading.
[0085] Element Mounting: With reference to FIG. 7, in some embodiments, the
DUV elements
21 are preferably mounted such that the XY plane through about the middle of
the elements is about in
alignment with convenient mounting of one or more UHF and VHF gain enhancing
components. E.g., the
DUV element structural contact 38 (and associated RF contact 44) are
preferably mounted in line with
12
CA 02604405 2007-11-01
preferred vertical configurations of UHF/VHF directors 50, and/or with VHF
reflective element 82, such
as inline with those elements mounted on top of the longitudinal boom 102. DUV
elements 21 preferably
each comprising two structural mounts 38 mounted about symmetrically about the
XY plane comprising
these respective UHF and/or VHF gain enhancing components. DUV elements 21 are
preferably mounted
within a U-Mount housing 211 that in turn mounts about the longitudinal boom
102.
[0086] The DUV elements 21 are preferably structurally mounted using a
supportive bonding
means such as an epoxy, potting or thermosetting material 228. E.g., the DUV
element supports 38 and
contacts 44 are potted within a housing 221 mounted on the longitudinal boom
102. This reduces element
flexure, fatigue and contact corrosion. In some configurations, potting 228 is
used to mount supports 38
and protect contacts 44 with shallow bends and/or without holes 220. RF
contact 236 may be bonded to
contact 236 on surfaces not in the XY plane. Such methods simplify
construction. The U-Mount
configuration beneficially enables the DUV dipole antenna to be conveniently
mounted in new antennas
or to be retrofitted to existing antennas.
100871 Cutout DUV Element: Such longer cutout DUV dipoles provided
unexpectedly higher
UHF DTV performance than prior art dipoles. The prior art Peterson dipole
element shown in FIG. 24 has
about a 168 mm (6.63 in) element length LE. A 162% longer DUV dipole
embodiment was made with
about a 273 mm (10.75 in) DUV element length LE and a similar 32 mm (1.25 in)
contact to contact
spacing LC. Similar to FIG. 3, the 152 mm (6 in) DUV material height was
configured with three folds 31
to form four DUV element portions 32 giving a folded element height HE of 102
mm (4 in). The outer
central portion of the DUV element was cut inwards by 146 mm (5.75 in) like
the element shown in FIG.
2. This DUV dipole showed about 5.3 to 4.8 dB higher performance than this
Peterson dipole in the VHF
High band for Channels 8, 10 and 12. Surprisingly, this DUV dipole also showed
about 3.5 to 0.5 dB higher
gain in the DTV UHF band across channels 18 to 46 than the Peterson dipole.
(Even in Channels 55 to 63
this large DUV dipole was within 2.5 dB of the Peterson dipole gain.) The DUV
cutout provides much
reduced wind resistance vs without.
[0088] With further reference to FIG. 7, in configurations such as where
further signal gain is
desired, an amplifier 202 is preferably configured near and connected to the
element RF contacts 44. More
preferably the respective amplifier RF contacts 236 are connected to the RF
contacts 44 using short flexible
leads 246. E.g., from sections of DUV line 246. More preferably, RF contacts
44 are electrically bonded
to the respective leads 246 which are electrically bonded to the respective
amplifier contacts. DUV
amplifier 202 is preferably mounted within a radius R from antenna pointing X
axis near the RF contacts
44. E.g., R is preferably less than the dipole element length LE, and more
preferably less than half the
element length LE. A corresponding signal line 260 is connected to the
amplifier signal contacts 246, and
preferably electrically bonded to them. Signal line 260 is preferably precut
to a common convenient length
with a corresponding RF connector bonded to the user end. E.g., 31 m (100 ft)
or 16 m (50 fft). This
connected configuration forms an amplified DUV dipole antenna that preferably
has only one user formable
connection at the end of the DUV line. This beneficially provides users with a
usable high RF signal gain
that avoids numerous losses from signal connections, and which does not
degrade with time from wear or
corrosion.
100891 With reference to FIG. 8, the DUV dipole antenna may be mounted on top
of the
longitudinal boom 102. This provides another convenient mount for new or
retrofit systems.
[0090] DUV Aster: With reference to FIG. 9, in some embodiments the driven
dipole is
configured as a DUV Diamond dipole 92 having a wider mid section in the YZ
plane relative to its smaller
inner end 99 and outer end 98. DUV Dipole 92 may comprise two DUV Aster
elements 91, comprising a
13
CA 02604405 2007-11-01
plurality of elongated RF conductive portions 42 radiating out from the RF
contact 44 on or near DUV
element support 38. E.g., DUV element 91 may comprise a plurality of wires or
elongated RF conductive
strips 42. Preferably, the RF conductive elongated portions 42 are formed with
at least three lengths
selected to form resonant dipoles 20 corresponding to wavelengths for at least
three RF signal frequencies.
More preferably, the elongated RF portion lengths are selected to form at
least five resonant dipoles 20 for
signal wavelengths corresponding to the center frequencies of at least five
transmission frequencies in at
least one of the VHF high band and UHF digital TV channels.
[0091] In some configurations, the plurality of elongated RF conductive
elements comprising the
DUV Aster 93 are more preferably configured on the DUV Fan configuration such
as shown in FIG. 2, and
FIG. 3. Referring to FIG. 4, the plurality of elongated RF conductive elements
42 are preferably formed
along a plurality of one or more inter perforation regions 35. They may be
formed along DUV folds 31, or
DUV element outer edges 33.
[0092] DUV Accordion: With reference to FIG. 10, in some embodiments, the
driven DUV dipole
may be formed as DUV Accordion dipole 94 comprising two DUV accordion elements
95 95 may
comprise multiple RF conductive elements 40 RF communicatively connected to an
intra antenna RF
conductor 294 and to RF contact 44. These RF conductive elements are mounted
on or part of an elongated
structural elementportions 32 supported by an Intra Antenna Boom 108 connected
to DUV element support
36. The distributed structural element is preferably formed into an accordion
type configuration with a
plurality of elongated elements 32 connected by folds 31. The RF conductive
elements may be configured
similar to the DUV Fan elements shown in FIG. 3, or the DUV Aster shown in
FIG. 9. The DUV accordion
is preferably perforated to reduce wind loading (such as the perforations 34
shown in FIG. 3.)
[0093] DUV Loops: With reference to FIG. 11, the DUV antenna may comprise a
DUV Loop
dipole 96 having multiple DUV loop elements 97 comprising a plurality of RF
conductive loops 46 RF
communicatively connected to RF contacts 44 supported by element structural
supports 36.
[0094] DUV Line: With reference to FIG. 2, in some configurations, the driven
DUV element 21
is preferably electromagnetically connected to the RF signal line 260. The
driven DUV element is
preferably electromagnetically coupled to the RF signal line 260 capable of
communicating an
electromagnetic signal. The coupling comprises at least one of a conductive,
capacitative, inductive, or
optical coupling. The coupling may comprise an impedance matching component or
balun. The RF signal
line 260 may comprise a two conductors. It preferably comprises a low loss
coax line, and more preferably
a fiber optic line.
[0095] For example, the RF contacts 44 of two DUV elements 21 comprising the
DUV Dipole
20, are preferably electrically bonded to an impedance matching balun. The
balun contacts are preferably
bonded to a prescribed length of high performance UHF/VHF line. E.g., 31 m
(100 ft) of RG-6 coax line.
A similar configuration may be fonmed by bonding a single DUV element 21 to a
balun to a DUV line.
[0096] More preferably, a RF optical line comprising an optical fiber, a RF
signal transmitter and
an RF signal receiver is used between the antenna amplifier 202 and a signal
junction or distribution box
280. The degradation of this optical line's RF signal to noise ratio between
the RF amplifier 202 and an
RF signal line connector 266 connected to one of the signal junction box 280
or a signal converter, does
not exceed about 3 dB per 31 m (100 ft) of signal line for UHF signals of at
least 400 MHz. E.g., the signal
converter may comprise a signal distribution system, a DTV receiver, and/or a
DTV transmitter.
[0097] Where the signal line 260 comprises an RF optical line, a power line
may be incorporated
along with the optical line in the signal line 260. Referring to FIG. 17, a
renewable energy power supply
302 and energy storage system 304 is preferably configured with the DUV
antenna to provide the requisite
14
CA 02604405 2007-11-01
power through a power line 292 for the amplifier and RF optic line transmitter
or receiver. E.g., these may
use a photovoltaic panel or small wind turbine together with a battery or
capacitor energy storage system.
100981 Contact or Amplifier housing: Referring to FIG. 22A and detail FIG.
22B, the DUV
element RF contacts and contacts for DUV line 208 (and any balun as needed)
are preferably encapsulated
and protected by a housing 204. The housing 204 is preferably formed from non-
conductive material such
as a plastic, cellulosic or glassy material. This beneficially reduces signal
reflection and multi-path
generation within the antenna. Referring to detail FIG. 22B, housing 204 is
more preferably formed from
an RF electromagnetically absorbing material 205. E.g., an RF resistively
conductive material that
attenuates incident RF signals reflected by the housing by about 3 dB or more.
This may use polypropylene
impregnated with 5% to 30% carbon black and preferably 7% to 15% carbon black.
This RF attenuation
further beneficially attenuates electromagnetic radiation incident on the
amplifier, RF leads and contacts
within the housing 204 by at least 3 dB. More preferably, the housing
comprises an RF conductive sheet,
mesh or enclosure 207 inside coating 205 to form an RF "Faraday Cage" to
isolate the amplifier from
transmitting incident RF signals. Housing 204 preferably comprises a second
resistive coating 205 interior
to enclosure 207.
[0099] Housing Surface: Referring to FIG. 22B, the surface 203 of the housing
204 is preferably
formed from or coated with a "white" material having a low visible
absorptivity and/or a high infrared
emissivity to reduce solar heat absorption and/or increase heat radiated from
the housing respectively. For
example, the housing and/or coating 203 may comprise one or more of zinc
sulfide, zirconium oxide,
titanium dioxide, barium sulfate, and micaceous ferric oxide to reduce optical
absorptivity and/or increase
IR emissivity. The ratio of visible electromagnetic absorptivity (0.3 to 3
micrometers) to infrared emissivity
(3 micrometers to 50 micrometers) is preferably less than 0.5, which
beneficially reduces solar heating of
the housing and any enclosed amplifier.
[00100] Sealed housing: Referring to FIG. 22A, the housing 204 is preferably
sealed by suitable
housing sea1208. E.g., a gasket, "O-Ring" or sealant. More preferably, the
balun, RF contacts and DUV
Line contacts are secured and sealed with a suitable UHF compliant potting
compound 228. This
configuration beneficially protects the contacts against flexure and/or
corrosive components such as
moisture. This reduces fatigue and corrosion. Referring to FIG. 22C, external
DUV line 260 is preferably
mounted on housing 204 with a strain relief cable mount 268 and sealed with
potting compound 228. This
beneficially reduces fluctuating strain on the amplifier from wind loading on
the DUV elements and the
DUV line, with a reduction of fatigue and potential failure probability.
[0101] Referring to FIG. 22A, the configuration of the DUV element 21 or DUV
dipole 20
bonded to a prescribed length of RF signal line 260 (including bonding to and
from any balun as needed)
provides consumers with a quality Digital UHFNHF Antenna having only one user
connectable electrical
connection. This DUV antenna configuration of DUV dipole, balun and DUV line
is useful by itself for
regions near major transmitters. This configuration beneficially minimizes the
number of connections
between the antenna driven element and the user application that can corrode
and degrade the UHF / VHF
signal transmission. This reduces one ofthe most common causes of progressive
TV reception degradation
and failure. It further prevents the common problem of fittings being
installed incorrectly, and incorrectly
configuring connections.
[0102] DUV Amplifier: With reference to FIG. 2, in some embodiments, an RF DUV
amplifier
202 is preferably connected between the two DUV elements 21 of the DUV dipole
20 and the RF signal
line 260. E.g., in a receiver, the two RF signal contacts 236 ofthe DUV
amplifier 202 are communicatively
bonded to the two RF contacts 44 ofthe DUV dipole 20 respectively. The
Amplifier Signal Output or input
CA 02604405 2007-11-01
of DUV amplifier 202 is RF communicatively connected to the RF signal line
260. E.g., Amplifier
electrical contacts 246 RF connected to DUV signal line 260. The DUV amplifier
202 preferably matches
impedance between the DUV antenna 20 and the RF signal line 260. An impedance
matcher or balun (not
shown) may be provided as needed between the DUV dipole 20 and the DUV
amplifier 202.
[0103] In some configurations, a grounded DUV amplifier 202 may be configured
between a
DUV element 21 and a DUV signal line 260. The RF contact of the DUV element 21
is bonded to the
amplifier input and the amplifier output bonded to the DUV signal line. When
the DUV antenna is used
as a transmitter, the amplifier 1/0 contacts are reversed.
[0104] Amplifier Gain: The DUV amplifier 202 preferably provides broad band
amplification
across a prescribed frequency range. The amplifier may be configured to
amplify one or both of VHF and
UHF signals. The amplifier is selected to provide at least 6 dB amplification.
It preferably has a switch
selectable gain to select from multiple gains in the range from 6 dB to 30 dB.
E.g., with 3 dB, 6 dB or 9
dB increments from 6 dB to 30 dB. For TV reception, the amplifier preferably
includes a suitable low pass
or notch filter (or "FM trap") to reduce the amplitude of FM signals relative
to TV signals.
101051 Amplifier Location: With reference to FIG. 2, the RF contacts 236 of
DUV amplifier 202
are RF communicatively connected to DUV element RF contacts 44. This may use a
length of RF line 290
shorter than DUV Dipole length LD, and preferably shorter than DUV element
length LE. More preferably,
the DUV amplifier RF contacts 236 are close coupled to the RF contacts 44
within a housing 204 using
electrically bonded connections.
[0106] Strain Relief Connections: Referring to FIG. 7, in some configurations
the DUV
amplifier's RF contacts 236 are connected directly to RF contacts 44 of the
DUV dipole 20 (or DUV
elements 21). Referring to FIG. 7, more preferably, a short strain relief RF
conductor 290 connects the RF
contact 44 with the DUV amplifier I/O contacts 236.
[0107] Bonded Contacts: Preferably, the 1/0 contacts between at least two of
the DUV antenna
and DUV amplifier 202, the DUV amplifier 202 and RF signal line 260,
(including any balun as needed)
are communicatively bonded together. E.g., by soldering, brazing, welding,
using a conductive adhesive,
or similarly electromagnetically connecting contacts. More preferably, the RF
line 246 is bonded between
the DUV element 21 and the DUV amplifier 1/0 contact. With an optical DUV
line, the optical lines may
similarly be fused together at the connections to provide a durable
connection.
[0108] Enhanced UHF/VHF DUV Antenna: With reference to FIG. 12, a UHFNHF
enhanced
DUV antenna 10 embodiment is preferably formed by configuring multiple RF
reflector elements 82 and
86 to increase the VHF gain of DUV elements 21 in some configurations. E.g.,
medium length VHF
reflector element 82 of about 732 mm (28.8 in) is preferably mounted on
longitudinal boom 102. Boom
102 is shown mounted on mast 150 with boom-mast mount 152. Similarly a VHF
reflector element 86
about 864 mm (34 in) long may be mounted on the longitudinal boom 102 with
bond 148 behind reflector
82, generally parallel to the driven DUV Elements 21. In some configurations,
a plurality of reflectors 82
and/or 86 may be configured above and below the longitudinal boom 102.
[0109] The reflector elements 82 and/or 86 are preferably configured to
resonate at frequencies
around the middle of a desired VHF range. The reflector elements 82 and/or 86
are more preferably
configured to resonate at a plurality of prescribed frequencies. These
resonant frequencies are more
preferably selected from among channel center frequencies within VHF High Band
of 174 MHz to 216
MHz. e.g., at least one of DTV Channels 7-13.
[0110] Further referring to FIG. 12, Dipole elements 21 are preferably
enhanced by RF director
140 comprising multiple RF director elements mounted on boom 102. RF director
elements are preferably
16
CA 02604405 2007-11-01
selected from a short RF director 52, a medium RF director 54, and a long RF
director 56. E.g., 178, 191,
and 203 mm (7, 7.5 and 8 in) long respectively for 9.5 mm (0.375 in) diameter
elements. More preferably,
at least one and preferably multiple director elements selected from 52, 54,
and 56 are configured to
resonate at one or more prescribed frequencies in the UHF range. Eg. One of
the frequencies corresponding
to the digital UHF TV band in the range of channels 14 to 51.
[0111] Dual UV-DUV Antenna: With reference to FIG. 13, one embodiment features
a dual DUV
antenna comprising two DUV dipoles configured for different frequency ranges
for enhanced UHF and/or
VHF performance. E.g., one configuration comprises a medium M-DUV dipole 24
comprising two M-
DUV elements 25 configured for the upper portion of the VHF High band from
about 192 MHz to 216
MHz, and a VBF enhanced V-DUV dipole 26 configured for the lower portion of
the VHF high band range
from about 174 MHz to 192 MHz for DTV. In this configuration, the V-DUV dipole
is preferably
configured around the lower portion of the VHF high band. E.g., a Fan type V-
DUV dipole with a dipole
end factor of 0.7 may have a tip to tip electrical half wave resonant length
LD of about 528 mm (20.8 in)
corresponding to a frequency of about 186 to 192 MHz (Channel 9.) This may
utilize V-DUV element 27
with lengths LE of about 248 mm (9.8 in) with 32 mm (1.25 in) contact to
contact spacing LC.
[0112] The M-DUV dipole 24 is more preferably configured to provide enhanced
gain at a
prescribed frequency near the upper portion of the VHF High Band. E.g., the
length LD of the M-DUV
dipole 24 may be configured for about 467 mm (18.45 in) for a Fan type DUV
dipole with an dipole end
factor of 0.7 for half wave resonance about 210-216 MHz (Channel 13.) E.g.,
length LE of M-DUV
element 25 maybe about 228 mm (8.6 in) with a contact-contact distance LC of
32 mm (1.25 in). This is
further three halves wave resonant at about 630-648 MHz (near digital Channels
59-62) in the new DTV
UHF band. This UV-DUV dipole combination beneficially has superior gain across
the UHF DTV band
as well as the VHF high band.
[0113] The RF contacts of the V-DUV dipole may be connected to the signal
cable or line 260,
preferably within a protective housing 204. Where increased gain is needed,
the RF contacts of the V-DUV
dipole antenna are preferably connected to a suitable DUV amplifier within the
housing 204, and the signal
line 260 leads are connected to the corresponding RF amplifier contacts.
[0114] VHF Reflector Enhancement: The V-DUV dipole 26 configuration shown in
FIG. 13 is
preferably mounted on a VHF longitudinal boom 104. Boom 104 is preferably
mounted on the mast 150
using a dual-axis orientable boom-mast mount 153. The V-DUV dipole is usually
enhanced by at least one
VHF resonant reflector element 80 mounted on the VHF boom 104, usually with a
bond 148, and
configured to be resonant for the prescribed VHF frequency range. E.g., near
the middle to lower end of
the VHF high band. The VHF reflective element 80 may be positioned between 20%
to 60% of the length
of the reflective element 80, and is preferably positioned between 30% and 50%
of that length, along the
VHF boom 104 in the negative X direction behind the V-DUV dipole 23. More
preferably the reflective
element 80 is positioned about in line with the longitudinal axis X about
parallel to the V-DUV dipole 26
at about 40% of the length of element 80 behind the V-DUV dipole. E.g., in one
configuration, the
reflective element 80 is about 864 mm (34 in) long for 9.5 mm (0.375 in)
diameter, and is positioned about
249 mm (13.75") behind the V-DUV dipole.
[0115] VHF Director Enhancement: V-DUV dipole 26 embodiment of FIG. 13 is
preferably
enhanced with a VHF director element 178 preferably positioned in the XY plane
symmetrically about the
antenna longitudinal axis X about parallel to the Y axis or V-DUV dipole 26.
The VHF director element
178 is preferably attached to boom 104 by bond 148 (or equivalent fastener),
and positioned between 30%
and 45% of its length in front of the V-DUV-dipole 26. The VHF director 178 is
preferably positioned
17
CA 02604405 2007-11-01
between 33% and 40%, and more preferably about 36.5% of its length in front of
the V-DUV dipole 26.
E.g., positioning a VHF director about 635 mm (25" long) at a distance of
about 232 mm (9.13") in front
of a V-DUV dipole about 737 mm (29") long. Each VHF director element is
preferably streamlined to
reduce wind loading in the X direction.
101161 Selective VHF Enhancement: Similarly, referring to FIG. 13, at least
one and preferably
both of the VHF resonant reflector element 80 and the VHF director 178 are
more preferably configured
to be resonant at a prescribed VHF frequency to enhance the antenna VHF gain
in some configurations.
The VHF reflector element 80 and VHF director 178 are preferably configured to
resonate near the upper
and lower ends of a prescribed VHF frequency range. More preferably VHF
elements 80 and 178 are
configured for the lower and upper frequencies of a particular DTV channel to
enhance the VHF gain for
that channel.
[0117] For example, in one configuration, VHF reflector 80 is preferably
configured to resonate
near and more preferably slightly below 174 MHz (e.g., digital Channel 7) near
or at the bottom of the VHF
high band. For this configuration, the VHF reflector 80 is preferably formed
to be about 864 mm (34")
long. Similarly, VHF director 178 preferably resonates at slightly above 216
MHz (digital Channel 13) at
the top end of the VHF high band. E.g., director 178 is preferably configured
to be about 610 mm (24")
long.
[0118] More preferably, the V-DUV dipole 26 is configured to improve
performance for a
particular Digital TV channel. E.g., to improve performance over 180 MHz to
186 MHz, (for DTV channel
8), the driven DUV dipole length LD is preferably configured about 775 mm
(30.5 in) long.
[0119] UHF configured U-DUV dipole: Referring to the dual UV-DUV antenna
embodiment
shown in FIG. 13, the V-DUV dipole 26 is preferably complemented by at least
one UHF enhanced U-
DUV or M-DUV dipole 22 that is configured for increased gain in the UHF range.
The U-DUV dipole 22
may be mounted on the mast 150, or preferably on an intra-antenna boom 108
above (or below) the V-DUV
dipole to form a UV-DUV antenna (or VU-DUV antenna). This U-DUV antenna is
preferably configured
for a prescribed UHF Range. E.g., for a select group of channels within the
DTV UHF range of 470 MHz
to 698 MHz (DTV channels 14-51.)
[0120] UHF Enhancement: Referring to the FIG. 13 embodiment, the U-DUV dipole
22 is
preferably provided with further UHF enhancement comprising one of a RF
director 140 in front of the U-
DUV dipole, and a UHF Screen Reflector 136 behind the U-DUV dipole. The RF
director 140 comprises
multiple UHFNHF director elements 52 on a UHF director boom 106. The UHF
Screen Reflector 136 may
be stiffened by at least one and preferably two stiffener elements or spars
107. The Screen Reflector 136
may be connected to at least one and preferably two standoffs 109. The
standoffs 109 may be mounted on
the intra antenna boom 108. The reflector width may be 125% to 300% of the
length LD of the U-DUV
dipole, and preferably about 170% the length of the U-DUV dipole. E.g., 737 mm
(29") wide for a 432 mm
(17") U-DUV dipole. The reflector height may be 200% to 900% of the U-DUV
dipole height HE, and
preferably about 500% of HE.
[0121] DUV Connections: Referring to FIG. 13, the RF contacts of at least one
of the DUV
dipoles 22 and 26 may be connected to at least one pair of DUV element leads
290 which j oin a common
RF signal line 260 near those dipoles. (Alternatively, a single DUV element
lead 290 may be used in single
sided configurations.) DUV element leads 290 are preferably supported by a
cable mount 268 to reduce
wind induced flexure and contact fatigue. More preferably, the RF contacts
from at least one DUV dipole
22 and/or 26 are connected to the RF contacts of at least one amplifier
(either directly or via DUV element
leads 290). The other RF amplifier contacts are then connected to the RF
signal lead 260 together with any
18
CA 02604405 2007-11-01
remaining unamplified signal leads 290. The amplifier and line connections are
preferably encased, and
more preferably bonded and sealed within at least one housing 204.
101221 Signal amplification: Referring to FIG. 13 DUV element leads 290 from U-
DUV dipole
22 are preferably connected to RF contacts of an UHF/VHF amplifier and more
preferably to a UHF
amplifier within housing 204. The RF contacts of V-DUV dipole are preferably
connected to VHF
amplifier within housing 204. The signal output (or input) of the UHF/VHF
amplifier or UHF amplifier
is preferably mixed with the VHF amplifier output (or input) and connected to
the signal line 260.
[0123] U-DUV or V-DUV applications: The UHF improved U-DUV dipole 22 or the
VHF
improved V-DUV dipole 26 described herein may be preferably used in single DUV
dipole configurations
to further improve the UHF or VHF signal gain. E.g., in the embodiments
depicted in one or more of FIG.
1, FIG. 2, FIG. 7, FIG. 8, and FIG 12, and the corresponding configurations
described herein.
[0124] Dual Axis Mount: With reference to FIG. 14, the longitudinal boom 102
may be clamped
to the mast 150. The longitudinal boom 102 is preferably mounted on the mast
150 with the dual axis
boom-mast mount 153. This dual axis boom-mast mount 153 is preferably
configurable to rotationally
position the DUV antenna about the longitudinal boom 102 (or equivalently
rotate antenna about the X
axis) and rotationally position the DUV antenna about the generally "vertical"
mast axis (or equivalently
about the driven antenna Z axis). It further enables "vertical" positioning
along the Z axis. The boom-mast
mount 153 preferably comprises a bicurved mount 154 positioned between
adjacent mast 150 and boom
mount 156 surrounding boom 102. The boom mount 156 for boom 102 is preferably
curved or rounded to
match the respective mating surface of bicurved mount 154. The surface of
curved boom mount 156 is
more preferably configured to accommodate two curvilinear restraining bolts
158 (or an equivalent
tricurved bolt). E.g., the surface of boom mount 156 comprises at least one
curved groove 157 for
curvilinear bolt 158.
[0125] Per FIG. 14, a complementary dual hole washer 160 is preferably
positioned on the other
side of mast 150. The curvilinear bolts 158 preferably go through a first hole
in dual hole washer 160, past
the mast 150, around the bicurved mount 154, back past mast 150, and through a
second hole of the dual
hole washer 160. The curvilinear bolts 158 may be tightened with nuts 160,
cams, or similar tighteners 161.
The surface of boom mount 156 may be formed using a cylindrical cover
surrounding the boom 102 and
bonded to it by a suitable component bond 149 such by welding, brazing,
soldering, adhesive etc.
101261 Mounting antenna boom to mast with boom-mast mount 153 may comprise a
single triply
curved curvilinear bolt (not shown) passing through one hole of dual hole
washer 160, past mast 150 and
bicurved mount 154, around boom mount 156 and thence back past bicurved mount
154, mast 150 and
through the second hole in dual hole washer 160. The dual axis mount 153
beneficially enables users to
orient the antenna to match a desired signal polarity relative to the antenna
longitudinal boom 102 as well
as orient the antenna in a prescribed azimuthal direction about the mast 150,
[0127] Structure Mast Mount: Referring to FIG. 14, the mast 150 may be mounted
to the structure
or ground 168 with a structure-mast mount 166. This structure mast mount 166
is preferably configured
to clamp mast 150 vertically, and optionally to orient and clamp mast 150 at a
desired azimuthal angle
about the vertical, using a second dual axis mount 153. This beneficially
enables the antenna to configured
in a prescribed azimuthal orientation about the zenith or axis perpendicular
to the X-axis.
101281 Lightning Protection: Referring to FIG. 14, a lightning rod 390 is
preferably mounted
above the antenna, and supported from the mast 150 by an insulated support
392. The lightning rod 390
is electrically isolated from the other components of the antenna system 12.
The lightning rod is connected
to earth ground 394 by grounding cable 396. Lightning rod 390 and cable 396
are preferably configured
19
CA 02604405 2007-11-01
behind VHF reflectors, booster and/or screens such as shown in FIG. 1, FIG.
12, FIG. 13, FIG. 15, FIG.
17 and/or FIG. 18. This positioning beneficially helps isolate lightning
electromagnetic pulse from the
DUV dipole. Considering the antenna is often the highest component of the
structure, this lightning
protection system beneficially provides some electrical protection to the
structure and antenna system
against lightning strikes.
[0129] Triple UVU-DUV Antenna: With reference to FIG. 15, another DUV antenna
system 2
embodiment comprises three DUV antennas configured for a plurality of UHF
and/or VHF ranges. E.g.,
the DUV antennas are preferably selected from U-DUV dipoles 22, M-DUV dipoles
24, and V-DUV
dipoles 26 to provide improved gain in the UHF and VHF frequency ranges, such
as to form a UVU-DUV
antenna as shown in FIG. 15. In another configuration, the UVU-DUV antenna may
comprise two U-DUV
dipoles 22 and/or M-DUV dipoles 24 configured above and/or below the V-DUV
dipole 26. VHF dipole
26 is preferably mounted on VHF longitudinal boom 104 which is mounted on mast
150 with a boom-mast
mount 152. RF contacts of U-DUV dipoles 22 and M-DUV may be connected by RF
leads 290 supported
by cable mounts 268 to cable 260 in housing 204.
101301 Referring further to FIG. 15, preferably one or more dipole RF contacts
or RF leads 290
are connected to one or more RF amplifiers 204. The amplifier signal contacts
are preferably connected or
mixed, (optionally with unamplified RF leads 290), to RF signal line 260. More
preferably, the RF contacts
of each of the DUV dipoles 22 and 26 are RF communicatively connected to
respective RF amplifiers 204.
The signal side of these RF amplifiers may be connected together, or
preferably mixed together and the
resultant RF signal fed to the RF signal line 260. More preferably the
amplifiers and line connections are
encased, bonded and sealed within multiple housings 204 positioned close to
the longitudinal axes of the
DUV dipoles 22 and 26.
[0131] Further referring to FIG. 15, the U-DUV dipoles 22 and/or M-DUV dipoles
24 are
preferably configured for at least one and more preferably for two prescribed
UHF ranges. E.g., one U-
DUV dipole 22 or M-DUV dipole 24 may be configured for UHF DTV Channels 14-31,
and the second
U-DUV dipole 22 or M-DUV 24 may be configured for UHF DTV Channels 32-51
respectively. In the
configuration shown in FIG. 15, the length LD ofthe lower M-DUV dipole 24
maybe configured for about
3/4 the length ofthe middle V-DUV dipole 26. Correspondingly, the length LD
ofthe upper U-DUV dipole
22 may configured for about 2/3 of the length LD of the middle V-DUV dipole
26.
[0132] One or more ofU-DUV dipole 22 or M-DUV dipole 24 maybe enhanced with RF
director
elements. E.g., the upper U-DUV dipole 22 in FIG. 15 is shown as UHF enhanced
with RF director 140
having three UHF director elements 52 mounted on the UHF director boom 106
supported by intra antenna
boom 108. VHF dipole 26 is may be enhanced by one and preferably both of VHF
reflector 80 mounted
behind dipole 26 on VHF boom 104 by bond 148 or equivalent fastener, and VHF
director 178 mounted
on boom 104 with bond 148 in front of VHF dipole 26.
[0133] Further referring to FIG. 15, the U-DUV antennae 22 and 24 are
preferably spaced above
and below the V-DUV dipole antenna to form a UVU-DUV antenna. Screens 136 are
preferably added to
boost UHF and/or VHF response of dipoles 22, 24 and/or 26. Reflector screens
136 may be supported by
spars 107 and connected via intra antenna standoff 109 to intra antenna boom
108. In such UVU-DUV
antenna configurations, UHF reflector screens 136 are preferably separated and
displaced from the V-DUV
dipole to provide substantial VHF enhancement from reflector screens 136
and/or VHF reflector 80. The
reflector screens 136 may be separated by 20% to 200% of the V-DUV dipole
length LD. They are
preferably separated by between 33% and 100%, and more preferably by about 50%
of the length of the
V-DUV dipole length LD. One or more similar UHF reflector screens 136 may be
formed from curved
CA 02604405 2007-11-01
conductive low drag material with similar restrictions on the spacing between
reflectors. One or more U-
DUV dipoles are preferably positioned at about the focal length corresponding
to the curvature of reflector
screens 136.
101341 Further referring to FIG. 15, the U-DUV dipoles 22 (and/or M-DUV
dipoles 24) may
similarly be configured together above or below the V-DUV dipole 26 to form
UUV-DUV antenna or
VUU-DUV antenna configurations. In other configurations, a triple VUV-DUV
antenna maybe configured
comprising two V-DUV dipoles 26 above and below one U-DUV dipole 22. These may
similarly be
configured as VVU-DUV antenna (or UVV-DUV antenna) with the U-DUV dipoles 22
below or above
the V-DUV dipoles 26. Other permutations of U-DUV, M-DUV and V-DUV dipoles may
be configured
to enhance response in corresponding prescribed frequency ranges.
101351 Side by Side Configurations: The multiple U-DUV and/or V-DUV
embodiments and
configurations described in FIG. 13, FIG. 15, and FIG. 17 may similarly be
configured with two or more
of U-DUV dipoles 22, M-DUV dipoles 24, and/or V-DUV dipoles 26 positioned side
by side. E.g.,
left/right along the Y axis. For example, two U-DUV dipoles 22 may be
configured side by side, and
together be positioned above, alongside and/or below a V-DUV dipole 26.
Correspondingly, the V-DUV
dipole 26 may be configured displaced along the Y axis to the left or right
from two U-DUV dipoles 22
positioned one above the other.
[0136] Multi DUV Dipole RF connections: Referring to FIG. 15, the DUV dipoles
may be
connected by DUV element RF signal leads 290 to the RF signal line 260. Each
of the DUV dipoles are
preferably connected to respective RF amplifiers. The corresponding RF
contacts of these RF amplifiers
may be connected together, or preferably mixed together and the RF signal
connected to the RF signal line
260. More preferably the amplifiers and line connections are encased, bonded
and sealed within a plurality
of housings 204 positioned near the respective DUV dipole contacts.
[0137] Five DUV antenna: With reference to FIG. 17, a combination of five DUV
dipoles,
comprising U-DUV dipoles 22, M-DUV dipoles and/or V-DUV dipoles 24, are
preferably configured into
a composite 5-DUV antenna system 2 to provide improved signal gain,
directivity, and/or front/back ratio.
Additional U-DUV dipole 22, (or M-DUV dipole 24 and/or V-DUV dipole 26,) are
added to improve the
respective UHF (or VHF) bands. E.g., by about 3 dB each. The U-DUV dipoles are
preferably further
enhanced by adding one or more RF directors 140 comprising UHF/VHF director
elements 52 mounted
on respective UHF longitudinal booms 106.
101381 Reflectors 136 are preferably positioned behind the U-DUV dipoles 22
and/or M-DUV
dipoles 24 along the negative X direction to improve UHF and/or VHF gain. The
reflectors 136 may be
stiffened by stiffener elements or spars 107 suitably mounted to optional
intra antenna standoff's 109 and
connected to one or more intra antenna booms 108 mounted to the VHF
longitudinal boom 104. The boom
104 is mounted on the mast 150 with a boom-mast mount (not shown) as in FIG.
12 or FIG. 13. Two to
three U-DUV dipoles beneficially improve the UHF gain by about 9 dB. The UHF
directors 52 improve
directivity and increase signal gain by about 1-2 dB.
[0139] As in FIG 1, UHF/VHF reflector elements may be provided (not shown in
FIG. 17). e.g.,
one to four UHF/VHF reflector elements maybe mounted above and/or below boom
104. These UHF/VHF
reflector elements may add about 2-5 dB over the UHF range (channels 14 to 51)
These U-DUV dipoles,
and UHF directors/reflectors may thus be configured to collectively provide
about 12 dB to 16 dB higher
gain as well as higher directivity.
[0140] DUV lead connection and/or amplification: Referring to FIG. 17, four or
five U-DUV, M-
DUV and/or V-DUV dipoles may be connected via DUV element leads 290 supported
by cable mounts 268
21
CA 02604405 2007-11-01
as needed to an RF amplifier in housing 204 with the output connected to RF
signal line 260. Preferably
multiple DUV dipoles and more preferably each of the DUV dipoles are close
coupled to respective RF
contacts on amplifies within multiple housings 204. The signal amplifier
connections may be connected
or preferably multiplexed together as described in FIG. 15.
101411 The U-DUV dipoles 22, M-DUV dipoles 24 and respective reflectors 136
are preferably
mounted in vertical pairs configured above and below the V-DUV dipole 26
mounted on the VHF boom
104. As described herein, the upper reflector 136 (or pair of reflectors 136)
are preferably separated from
the lower reflector 136 (or pair of reflectors 136). The separation between
upper and lower reflectors may
be configured with a gap of 20% to 200%, preferably 33% to 100%, and more
preferably with a gap of
about 50% of the length of the V-DUV dipole 26. The U-DUV dipoles 22 and/or M-
DUV dipoles 24 and
respective reflectors 136 may also be configured in horizontal side by side
pairs and configured to the left
and/or right of the V-DUV dipole 26.
[0142] VHF Enhancements: Further referring to FIG. 17, the VHF dipole 26 is
preferably
enhanced by one or more of VHF reflectors 80, and/or VHF director 178
positioned on VHF boom 104 and
bonded to it with bond 148 or equivalent fastener.
[0143] Vertical DUV Dipole Positioning: At least one and preferably multiple
DUV-dipoles may
be vertically positioned during installation at between 50% and 150% of the
peak signal relative to the
signal minimum to maximum along a vertical axis. The DUV dipoles are
preferably installed between 75%
and 125% of the peak signal vertical location, more preferably between 82% and
108%, and most
preferably between 97% and 103% of the peak signal vertical location. This
beneficially utilizes the signal
enhancement from moire patterns due to reflected signals.
[0144] Referring to Figures 13, 15 and 17, because UHF signals have different
wavelengths,
moire pattems and fringe intervals from VHF signals, at least one U-DUV dipole
22, M-DUV dipole 24
and/or V-DUV dipole 26 is preferably vertically positioned to benefit from
local signal moire fringe
maximums. Multiple dipoles 22, 24 and/or 26 are more preferably configured
vertically so that each U-
DUV dipole is positioned near a corresponding UHF fringe maximum.
[0145] VHF Booster DUV antenna: Referring to FIG. 18, in one embodiment, a
VHF/UHF
enhanced DUV antenna 10 is preferably configured with one and more preferably
two VHF RF boosters
110 comprising long VHF reflector elements 64 mounted on booms 122 configured
to reflect VHF signals
onto DUV dipole 12. VHF RF boosters 110 are mounted to longitudinal boom 102
by mount 120 behind
DUV dipole 12 and VHF reflector element 86. Longitudinal boom 102 may be
mounted using boom-mast
mount 152, or preferably a dual axis boom-mast mount. DUV dipole 12 is
preferably configured to resonate
in the VHF High band. This embodiment enhances UHF response with RF director
140 comprising
multiple elements 52 mounted on boom 102. The RF signal is preferably boosted
by amplifier 202 in
housing 204 close coupled to DUV antenna 12.
[0146] UHF reflector: Referring to FIG. 1 and FIG. 18, in some configurations,
a UHF reflector
54 is mounted on the longitudinal axis behind the driven antenna. In
configurations having RF boosters 110
comprising off axis reflective elements 64, UHF reflector 54 is preferably
configured for resonance in the
low UHF range. UHF reflector 54 may be positioned behind the DUV dipole by a
distance of between one
eighths and three eighths, more preferably between about three sixteenths and
five sixteenths, and more
preferably still by about one quarter the length of UHF reflector. E.g.,
reflector 54 about 432 mm (17 in)
long was positioned about 114 mm (4.5 in) behind the DUV dipole. This
configuration increased the
forward gain by about 0.7 dB to 1.5 dB, and improved the FrontBack ratio by
about 3 dB. This UHF
reflector 54 is situated to balance benefits in both the UHF DTV and VHF High
Bands.
22
CA 02604405 2007-11-01
[0147] Element Streamlining: Referring to FIG. 1, in some configurations, the
reflector and/or
director elements extending transversely to the X axis are preferably
streamlined. E.g., by forming the
element into an elliptical shape in the XZ plane with a smaller outer
dimension along the Z axis relative
to a longer outer dimension along the X axis. Referring to FIG. 16 and FIG.
21, VHF reflector elements
85 are preferably streamlined along the X axis.
101481 Element Tapering: Referring to FIG. 16 and FIG. 21, VHF reflector
elements 85 are
preferably tapered from large at the center down to the element tips. This
improves the bending strength
while reducing horizontal wind drag. Similarly referring to FIG. 18 and FIG.
19, in some configurations,
VHF reflectors 86 or 82, UHF reflectors 54, and/or UHF directors 52 are formed
with one or more
stiffening bends 66 to stiffen them and increase the bending moment about the
X axis. These reflectors or
directors are preferably tapered vertically from the longitudinal X axis out
to near the element tip. E.g., the
long edges of the director elements 52 are bent upwards to form a triangular
or tetrahedral stiffener shape
66 with a short stiffener peak positioned about over the center of the UHF
director boom 106 (or the X
axis). This provides the highest bending stiffness near the middle tapering to
the tips. It further reduces
wind loading along the X axis.
[0149] In some configurations, the edges of the director elements 52 are bent
upwards closer to
the longitudinal axis of the UHF element near the mount on the boom compared
to the outer tips. This
beneficially enables the UHF element 52 to be stamped out ofrectangular
material. In some configurations,
an indented stiffener ridge 68 or curved channel is preferably pressed upward
about along the axis of the
UHF element 52 (about parallel to the Y axis.) This reduces the upward "lift"
of the UHF element 52 from
the side bends.
[0150] In some configurations, the UHF elements 50 andJor VHF elements 80 are
preferably
stamped out with stiffening risers 66 from diamond shaped material. This
provides greater bending stiffness
near the X axis tapering to thinner sections near the element tips. The ends
of reflective elements 54, 64,
or 86, or directive elements 52 are preferably bent upwards for a short
distance forming a folded tip 69.
This beneficially reduces personal impact hazards and reduces the physical
length, facilitating packing and
shipping.
[0151] Tapered Booster Reflector Elements: Referring to FIG. 18 and FIG. 20,
in some
configurations UHF booster elements 62 and/or VHF booster elements 64 are
preferably bent into shape
from flat material with a stiffener on one side bent up and the stiffener on
the other side bent down in a Z
type pattern. An inner booster attachment tab 58 and/or an outer booster
attachment tab 59 are preferably
provided on booster reflector element 62 or 64 to attach them to booster boom
122 using fasteners or
bonding methods.
[0152] Tapered conical streamlined elements: Referring to FIG. 20, in some
configurations the
VHF elements 80 and/or UHF elements are preferably tapered from their mounting
location in the middle
outwards the element tips as well as being streamlined. E.g., by forming the
outward portions into truncated
conical sections joined at their bases about the middle. The mounting location
is preferably flattened to
facilitate bonding to the respective boom. Where a mounting fastener such as a
bolt, or rivet is used, a
flattened area and/or a hole 71 is preferably provided on the opposite side
ofthe conical section to facilitate
attachment. The conical elements are preferably streamlined into a elliptical
conical section to further
reduce wind loading. A fastener hole 71 may be configured in the outer surface
of the tapered conical
reflector 85 about the center. The ends of the tapered conical sections may be
cut at a diagonal, reoriented
along the X axis, and reconnected. This beneficially reduces the shipping
dimension along the Y axis and
reduces eye hazzards.
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CA 02604405 2007-11-01
[0153] Generally, preferably one or more of the VHF and UHF enhancing elements
are
streamlined and/or tapered so that the horizontal drag of the VHF or UHF
enhancing element is less than
85% of the drag of an enhancing cylindrical element of equal length and cross
sectional area.
101541 F-DUV Digital FM antenna: With reference to FIG. 1, in some
embodiments, the DUV
antenna 2 is preferably configured as a F-DUV antenna for the FM range. E.g.,
about 88 MHz to 108 MH
for digital FM use. For an F-DUV antenna configuration, the amplifier 202 is
preferably configured for that
FM frequency band, preferably with bandpass filters to select that range and
reject nearby DTV signals.
For such an F-DUV antenna, one or more of the DUV elements 21, the reflector
82, and the directors 50
and boosters elements 62 preferably configured for the FM spectrum to improve
the gain and the front/back
ratio.
[0155] I-DUV Digital Internet antenna: With reference to FIG. 1, in some
embodiments, the
antenna 10 is preferably configured as anI-DUV antenna for the high "Internet"
UHF range from about 698
MHz to 801 MHz, or similar UHF range above the UHF DTV range.
[0156] More preferably, in some embodiments multiple amplifiers are provided,
configured for
the respective frequency ranges. The amplifiers for the FM, DTV and/or
Internet ranges are more preferably
configured with appropriate filters (e.g., bandpass, low pass, high pass or
diplex filters as needed) to
separately amplify and/or transmit the respective signals. Similarly, separate
RF signal lines are also
preferablyprovided for the FM, DTV and/or Internet signals. More preferably
the FM, DTV and/or Internet
signals are communicated using one or more optical fibers.
Generalization
[0157] From the foregoing description, it will be appreciated that a novel
approach for forming
Digital UHF / VHF antennas has been disclosed using one or more methods
described herein. While the
components, techniques and aspects of the invention have been described with a
certain degree of
particularity, it is manifest that many changes may be made in the specific
designs, constructions and
methodology herein above described without departing from the spirit and scope
of this disclosure.
[0158] Where dimensions are given they are generally for illustrative purpose
and are not
prescriptive. As the skilled artisan will appreciate, other suitable materials
and components may be
efficaciously utilized, as needed or desired, giving due consideration to the
goals of achieving one or more
of the benefits and advantages as taught or suggested herein.
[0159] While certain antenna configurations, driven elements, director
elements, reflector
elements, resonant elements, amplifiers, lines, baluns, bonds, supports and
mounts are shown in some
configuration for some embodiments, combinations of those configurations may
be efficaciously utilized.
The active and/or passive element lengths, heights, spacing and other element,
component, and structural
dimensions and parameters for antenna systems may be used.
101601 Where the terms RF, VHF, UHF, FM, Intemet, driven, active, passive,
reflector, and
director have been used, the methods are generally applicable to other
combinations of those elements.
Where streamlined and/or tapered elements are described, other stamped or
cylindrical elements may be
used.
(0161] Where assembly methods are described, various alternative assembly
methods may be
efficaciously utilized to achieve configurations to achieve the benefits and
advantages of one or more of
the embodiments as taught or suggested herein.
[0162] Where longitudinal, axial, transverse, vertical, orientation, or other
directions are referred
to, it will be appreciated that any general coordinate system using
curvilinear coordinates may be utilized.
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CA 02604405 2007-11-01
Similarly, the antenna element orientations may be generally rearranged to
achieve other beneficial
combinations of the features and methods described.
[0163] While the components, techniques and aspects of the invention have been
described with
a certain degree of particularity, it is manifest that many changes may be
made in the specific designs,
constructions and methodology herein above described without departing from
the spirit and scope of this
disclosure.
[0164] Various modifications and applications of the invention may occur to
those who are skilled
in the art, without departing from the true spirit or scope of the invention.
It should be understood that the
invention is not limited to the embodiments set forth herein for purposes of
exemplification, but includes
the full range of equivalency to which each element is entitled.
