Note: Descriptions are shown in the official language in which they were submitted.
CA 02546488 2006-05-25
MOBILE WIRELESS COMMUNICATIONS DEVICE COMPRISING A
SATELLITE POSITIONING SYSTEM ANTENNA AND ELECTRICALLY
CONDUCTIVE DIRECTOR ELEMENT THEREFOR
Field of the Invention
The present invention relates to the field of communications devices, and,
more
particularly, to mobile wireless communications devices and related methods.
Background of the Invention
Cellular communications systems continue to grow in popularity and have become
an integral part of both personal and business communications. Cellular
telephones allow
users to place and receive voice calls most anywhere they travel. Moreover, as
cellular
telephone technology has increased, so too has the functionality of cellular
devices. For
example, many cellular devices now incorporate personal digital assistant
(PDA) features
such as calendars, address books, task lists, etc. Moreover, such mufti-
function devices
may also allow users to wirelessly send and receive electronic mail (email)
messages and
access the Internet via a cellular network and/or a wireless local area
network (WLAN),
for example.
Another feature which is being coupled with cellular communications
capabilities
is satellite positioning. That is, certain devices now incorporate both
cellular and satellite
positioning devices, such as global positioning system (GPS) devices, for
example. One
such device is described in U.S. Patent No. 6,857,016 to Motoyama et al.,
which is
directed to a computer remote position reporting device which includes a
global
positioning system (GPS) receiver, monitoring software and an Internet access
module for
tracking and mapping a position of a mobile object. In one embodiment, the
obtained
positions are collected, logged and communicated to a desired location by a
store-and-
forward protocol (e.g., Internet e-mail) or a direct-connection protocol
(e.g., file transfer
protocol (FTP)) via a wireless cellular transceiver.
As the functionality of cellular communications devices continues to increase,
so
too does the demand for smaller devices which are easier and more convenient
for users to
carry. As such, incorporating GPS capabilities in ever-smaller cellular phones
becomes
increasingly difficult, as smaller GPS antenna designs are required due to
space
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constraints. Thus, one challenge for designers is to provide GPS antennas with
adequate
signal reception characteristics yet in a relatively small size.
Various attempts have been made improve mobile device satellite positioning
antennas. An antenna arrangement for a GPS signal processing device is
disclosed in U.S.
Patent No. 6,720,923 to Hayward et al. in which an antenna member is mounted
on a
circuit board. The antenna member includes first, second, and third surfaces.
The third
surface adjoins the first and second surfaces. The first, second and third
surfaces define a
cavity within which is disposed dielectric material. At least one conductive
connector
comprising first and second ends is in communication with the antenna member
first
surface, and an amplifier is in communication with each conductive connector
second end.
Another example is set forth in PCT publication no. WO 02/29988 Al, which
discloses a folded inverted F antenna (FIFA) which includes an L-shaped
receiving
element having a first planar portion and a second planar portion connected
along a fold
edge. A printed circuit board (PCB) is disposed perpendicular to the second
planar portion
forming a PCB ground plane. The FIFA includes a second ground plane disposed
below
and in parallel with the second planar portion. Shorting conductors couple the
receiving
element to the PCB and the second ground plane, and a receive conductor
couples a
receiver circuit to the receiving element. The FIFA is for use in a wireless
communications
device, such as a cellular phone, for receiving position signals from a GPS
satellite.
Despite the availability of such GPS antenna configurations, other GPS antenna
configurations may be desirable which are relatively compact yet still provide
desired
beam direction or shaping for optimizing GPS satellite signal reception, for
example.
Brief Description of the Drawings
FIG. 1 is a schematic block diagram of a mobile wireless communications device
in accordance with the present invention.
FIG. 2 is a schematic block diagram of an alternate embodiment of the mobile
wireless communication device of FIG. 1.
FIG. 3 is a schematic perspective view of a PCB and antenna arrangement for
the
wireless communications device of FIG. 1.
FIG. 4 is a schematic block diagram of the wireless communications device of
FIG. 1 illustrating satellite positioning information display features
thereof.
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FIG. 5 is a schematic perspective view of an alternate embodiment of a PCB and
antenna arrangement for the wireless communications device of FIG. 1.
FIG. 6 is a schematic block diagram of an exemplary mobile wireless
communications device arrangement for use with the present invention.
FIG. 7 is a schematic diagram of a prior art monopole antenna.
FIG. 8 is a schematic diagram of a monopole antenna and associated
electrically
conductive director element in accordance with the present invention used for
a
performance test comparison with respect to the prior art antenna of FIG. 7.
Detailed Description of the Preferred Embodiments
In view of the foregoing background, it is therefore an object of the present
invention to provide a mobile wireless communications device including
satellite
positioning capabilities with enhanced satellite signal reception
characteristics and related
methods.
This and other objects, features, and advantages in accordance with the
present
invention are provided by a mobile wireless communications device which may
include an
antenna and at least one electrically conductive director therefor. More
particularly, the
mobile wireless communications may include a portable housing, and at least
one wireless
transceiver carried by the portable housing, and a satellite positioning
signal receiver
carried by the portable housing. The antenna may also be carned by the
portable housing
and connected to the satellite positioning signal receiver. Further, the at
least one
electrically conductive director element may be carried by the portable
housing in spaced
apart relation from the antenna and inductively coupled thereto for directing
a beam
pattern thereof. That is, the director elements) advantageously directs or
shapes the beam
pattern of the antenna to provide desired satellite signal reception, and may
further provide
improved antenna efficiency.
The mobile wireless communications device may further include a printed
circuit
board (PCB) carried by the portable housing, and the antenna and the PCB may
be
relatively positioned so that the PCB further directs the beam pattern of the
antenna. For
example, the antenna may include one or more electrically conductive traces on
the PCB,
and the PCB may be positioned to provide a reflector for directing the antenna
beam
pattern skyward for improved satellite positioning signal reception
performance. In one
embodiment, the a dielectric extension may extend outwardly from the PCB, and
the
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antenna may be carried by the dielectric extension. The electrically
conductive director
elements) may also be carried by the dielectric extension.
The portable housing may have an upper portion and a lower portion, and the
antenna may be positioned adjacent the upper portion of the portable housing.
Moreover,
the at least one wireless transceiver may be a cellular transceiver, and the
device may
further include a cellular antenna carried by the portable housing and
connected to the
cellular transceiver. By way of example, the cellular antenna may be carried
adjacent the
bottom portion of the portable housing.
The at least one electrically conductive director element may include a pair
of
parallel, spaced apart electrically conductive director elements, for example.
The device
may further include a controller carried by the portable housing and connected
to the
satellite positioning signal receiver, and a display carried by the portable
housing and
cooperating with the controller for displaying satellite positioning
information. By way of
example, the antenna maybe an inverted F antenna or a monopole antenna.
A method aspect of the invention is for making a mobile wireless
communications
device, such as the one described briefly above. The method may include
positioning a
satellite positioning signal receiver and at least one wireless transceiver in
a portable
housing, and connecting an antenna carried by the portable housing to the
satellite
positioning signal receiver. Further, at least one electrically conductive
director element
may be positioned in spaced apart relation from the antenna to be inductively
coupled
thereto for directing a beam pattern thereof.
The present invention will now be described more fully hereinafter with
reference
to the accompanying drawings, in which preferred embodiments of the invention
are
shown. This invention may, however, be embodied in many different forms and
should not
be construed as limited to the embodiments set forth herein. Rather, these
embodiments
are provided so that this disclosure will be thorough and complete, and will
fully convey
the scope of the invention to those skilled in the art. Like numbers refer to
like elements
throughout, and prime notation is used to indicate similar elements in
alternate
embodiments.
Referring initially to FIGS. 1 and 2, a mobile wireless communications device
20
in accordance with the present invention illustratively includes a portable
housing 21 and
one or more wireless transceivers 22 carried by the portable housing. In the
example
illustrated in FIG. 2, a cellular transceiver 22' cooperates with a cellular
antenna 23' to
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communicate over a cellular network 24' via a base stations) 25', which is
shown as a cell
tower for clarity of illustration. In other embodiments, the wireless
transceiver 22 be a
wireless local or personal area network (LAN/PAN) transceiver for
communicating via a
wireless LAN/PAN, for example. In still further embodiments, both cellular and
wireless
LAN/PAN transceivers may be included, as will be appreciated by those skilled
in the art.
The device 20 further illustratively includes a satellite positioning signal
receiver
26 carried by the portable housing. By way of example, the satellite
positioning signal
receiver 26 may be a GPS receiver, although receivers compatible with other
satellite
positioning systems such as Galileo, for example, may also be used. An antenna
27 is also
carried by the portable housing 21 and is connected to the satellite
positioning signal
receiver 26 for receiving positioning signals from GPS satellites 28, as will
be appreciated
by those skilled in the art. It should be noted that in some embodiments the
antenna 27
may also be connected to the wireless transceivers) 22 and used for
communicating over
a wireless networks) as well, as will be appreciated by those skilled in the
art.
Further, the device 20 also illustratively includes one or more electrically
conductive director elements 29 carried by the portable housing 21 in spaced
apart relation
from the satellite positioning system antenna 27 and inductively coupled
thereto for
directing a beam pattern thereof. That is, the director elements) 29
advantageously directs
or shapes the beam pattern of the antenna 27 skyward toward the GPS satellites
28 when
the mobile wireless communications device 20 is held in an operating position,
as will be
discussed further below.
Turning now additionally to FIGS. 3 and 4, the mobile wireless communications
device 20 may further include a printed circuit board (PCB) 30 carried by the
portable
housing 21. In the illustrated embodiment, the satellite positioning signal
receiver 26 is
illustratively shown as a signal source for clarity of illustration. The
antenna 23 and the
PCB 30 are relatively positioned so that the PCB further directs the beam
pattern of the
antenna. More particularly, in the illustrated embodiment the antenna 23 is a
monopole
antenna comprising a printed circuit element on an upper surface of the PCB
30.
Furthermore, a pair of electrically conductive parallel spaced-apart traces
provide directors
29a, 29b for the antenna 23.
The device 20 further illustratively includes a controller 31 carried by the
portable
housing 21 and connected to the satellite positioning signal receiver 26, and
a display 32
carried by the portable housing and cooperating with the controller for
displaying satellite
CA 02546488 2006-05-25
positioning information. By way of example, the controller 31 may include a
microprocessor and associated circuitry/memory, and the display 32 may be a
liquid
crystal display (LCD), although other suitable components or displays may also
be used.
While not shown in FIG. 4, the controller 31 may be carried by the PCB 30, as
will be
appreciated by those skilled in the art. It should be noted that those
components which are
within the portable housing and not externally viewable are shown with dashed
lines for
clarity of illustration in FIG. 4.
When using the GPS function of the device 20 a user may hold the device in an
operating position in which the display 32 is viewable to the user. In the
exemplary
embodiment, the controller 31 executes a mapping program which translates the
positioning data received from the satellite positioning signal receiver 26
into location
coordinates which are displayed at a corresponding location on a map, as will
be readily
appreciated by those skilled in the art. Thus, when the user holds the device
20 so that the
display 32 faces him in an operating position, the PCB 30 serves as a
reflector for
directing the antenna beam pattern skyward for improved satellite positioning
signal
reception performance. The director elements 29a, 29b not only help
direct/shape the
beam pattern in the desired direction, they may also provide improved antenna
efficiency.
By way of example, the performance of a first monopole antenna 70 (FIG. 7)
without a director element was compared with that of a second monopole antenna
80
having an electrically conductive director element 81 inductively coupled
thereto, as
shown in FIG. 8. Both of the first and second antennas 70, 80 were mounted
adjacent the
top end of a mobile phone circuit board for testing, similar to the
configuration illustrated
in FIG. 5. The first antenna 70 was designed to provide peak gain over the
frequencies of
interest. However, as will be appreciated by those skilled in the art,
inductively coupling
the director element 81 to the first antenna 70 would change the
characteristics of the
antenna such that it would no longer provide peak gain over the same
frequencies. Thus, to
provide a meaningful comparison, the second antenna 80 was designed such that
when the
director element 81 was coupled thereto, its peak gain would also occur over
the same
frequencies as the first antenna 70 without a director element. With the
director element 81
inductively coupled to the second antenna 80, the second antenna provided
better than a 1
dB improvement in average gain with respect to the first antenna 70 at three
different test
frequencies, as summarized in Table 1, below.
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1565.42 MHZ 1575.42 MHZ 1585.42 MHZ
Gain of First Antenna-4.06188 dB -4.20504 dB -4.51069
70 dB
With No Director Element
Gain of Second Antenna-2.96706 dB -2.94389 dB -3.13042
80 dB
With Director Element
81
Table 1
In accordance with an alternate embodiment now described with reference to
FIG. 5, a dielectric extension 33' illustratively extends outwardly from the
PCB 30', and
the antenna 23' and electrically conductive director element 29' are carried
on an upper
surface of the dielectric extension. In the exemplary embodiment, the antenna
23' is a
printed inverted F antenna, although other antenna configurations than those
shown herein
may also be used. The director element 29' may also be a printed conductive
trace or
traces on the dielectric extension 33'.
The dielectric extension 33' and antenna 23' may advantageously be positioned
adjacent an upper portion or top of the portable housing 21' using this
configuration. This
configuration also advantageously directs or shapes the beam pattern skyward
when a user
holds the device 20 so that he can see the display 32, as will be appreciated
by those
skilled in the art. Moreover, this allows the cellular (or other wireless)
antenna 23 to be
carried adjacent the bottom portion of the portable housing 21, as
schematically illustrated
in FIG. 2. This not only provides for reduced interference between the two
antennas, but it
may also help with specific absorption ratio (SAR) compliance by moving the
cellular
antenna 23 further away from a user's brain when he places the input audio
transducer of
the device 20 (not shown) adjacent his ear, as will also be appreciated by
those skilled in
the art.
A method aspect of the invention is for making the mobile wireless
communications device 20 and may include positioning a satellite positioning
signal
receiver 26 and at least one wireless transceiver 22 in a portable housing 21,
and
connecting an antenna 27 carried by the portable housing to the satellite
positioning signal
receiver. Further, at least one electrically conductive director element 29 is
positioned in
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spaced apart relation from the antenna 27 and inductively coupled thereto for
directing a
beam pattern thereof, as discussed further above.
Additional features and components of a mobile wireless communication device
in
accordance with the present invention will be further understood with
reference to FIG. 6.
The device 1000 includes a housing 1200, a keyboard 1400 and an output device
1600.
The output device shown is a display 1600, which is preferably a full graphic
LCD. Other
types of output devices may alternatively be utilized. A processing device
1800 is
contained within the housing 1200 and is coupled between the keyboard 1400 and
the
display 1600. The processing device 1800 controls the operation of the display
1600, as
well as the overall operation of the mobile device 1000, in response to
actuation of keys on
the keyboard 1400 by the user.
The housing 1200 may be elongated vertically, or may take on other sizes and
shapes (including clamshell housing structures). The keyboard may include a
mode
selection key, or other hardware or software for switching between text entry
and
telephony entry.
In addition to the processing device 1800, other parts of the mobile device
1000 are
shown schematically in FIG. 6. These include a communications subsystem 1001;
a short-
range communications subsystem 1020; the keyboard 1400 and the display 1600,
along
with other input/output devices 1060, 1080, 1100 and 1120; as well as memory
devices
1160, 1180 and various other device subsystems 1201. The mobile device 1000 is
preferably a two-way RF communications device having voice and data
communications
capabilities. In addition, the mobile device 1000 preferably has the
capability to
communicate with other computer systems via the Internet.
Operating system software executed by the processing device 1800 is preferably
stored in a persistent store, such as the flash memory 1160, but may be stored
in other
types of memory devices, such as a read only memory (ROM) or similar storage
element.
In addition, system software, specific device applications, or parts thereof,
may be
temporarily loaded into a volatile store, such as the random access memory
(RAM) 1180.
Communications signals received by the mobile device may also be stored in the
RAM
1180.
The processing device 1800, in addition to its operating system functions,
enables
execution of software applications 1300A-1300N on the device 1000. A
predetermined set
of applications that control basic device operations, such as data and voice
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communications 1300A and 1300B, may be installed on the device 1000 during
manufacture. In addition; a personal information manager (PIM) application may
be
installed during manufacture. The PIM is preferably capable of organizing and
managing
data items, such as e-mail, calendar events, voice mails, appointments, and
task items. The
PIM application is also preferably capable of sending and receiving data items
via a
wireless network 1401. Preferably, the PIM data items are seamlessly
integrated,
synchronized and updated via the wireless network 1401 with the device user's
corresponding data items stored or associated with a host computer system.
Communication functions, including data and voice communications, are
performed through the communications subsystem 1001, and possibly through the
short-
range communications subsystem. The communications subsystem 1001 includes a
receiver 1500, a transmitter 1520, and one or more antennas 1540 and 1560. In
addition,
the communications subsystem 1001 also includes a processing module, such as a
digital
signal processor (DSP) 1580, and local oscillators (LOs) 1601. The specific
design and
implementation of the communications subsystem 1001 is dependent upon the
communications network in which the mobile device 1000 is intended to operate.
For
example, a mobile device 1000 may include a communications subsystem 1001
designed
to operate with the MobitexTM, Data TACTM or General Packet Radio Service
(GPRS)
mobile data communications networks, and also designed to operate with any of
a variety
of voice communications networks, such as AMPS, TDMA, CDMA, PCS, GSM, etc.
Other types of data and voice networks, both separate and integrated, may also
be utilized
with the mobile device 1000.
Network access requirements vary depending upon the type of communication
system. For example, in the Mobitex and DataTAC networks, mobile devices are
registered on the network using a unique personal identification number or PIN
associated
with each device. In GPRS networks, however, network access is associated with
a
subscriber or user of a device. A GPRS device therefore requires a subscriber
identity
module, commonly referred to as a SIM card, in order to operate on a GPRS
network.
When required network registration or activation procedures have been
completed,
the mobile device 1000 may send and receive communications signals over the
communication network 1401. Signals received from the communications network
1401
by the antenna 1540 are routed to the receiver 1500, which provides for signal
amplification, frequency down conversion, filtering, channel selection, etc.,
and may also
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provide analog to digital conversion. Analog-to-digital conversion of the
received signal
allows the DSP 1580 to perform more complex communications functions, such as
demodulation and decoding. In a similar manner, signals to be transmitted to
the network
1401 are processed (e.g. modulated and encoded) by the DSP 1580 and are then
provided
to the transmitter 1520 for digital to analog conversion, frequency up
conversion, filtering,
amplification and transmission to the communication network 1401 (or networks)
via the
antenna 1560.
In addition to processing communications signals, the DSP 1580 provides for
control of the receiver 1500 and the transmitter 1520. For example, gains
applied to
communications signals in the receiver 1500 and transmitter 1520 may be
adaptively
controlled through automatic gain control algorithms implemented in the DSP
1580.
In a data communications mode, a received signal, such as a text message or
web
page download, is processed by the communications subsystem 1001 and is input
to the
processing device 1800. The received signal is then further processed by the
processing
device 1800 for an output to the display 1600, or alternatively to some other
auxiliary I/O
device 1060. A device user may also compose data items, such as e-mail
messages, using
the keyboard 1400 and/or some other auxiliary I/O device 1060, such as a
touchpad, a
rocker switch, a thumb-wheel, or some other type of input device. The composed
data
items may then be transmitted over the communications network 1401 via the
communications subsystem 1001.
In a voice communications mode, overall operation of the device is
substantially
similar to the data communications mode, except that received signals are
output to a
speaker 1100, and signals for transmission are generated by a microphone 1120.
Alternative voice or audio I/O subsystems, such as a voice message recording
subsystem,
may also be implemented on the device 1000. In addition, the display 1600 may
also be
utilized in voice communications mode, for example to display the identity of
a calling
party, the duration of a voice call, or other voice call related information.
The short-range communications subsystem enables communication between the
mobile device 1000 and other proximate systems or devices, which need not
necessarily
be similar devices. For example, the short-range communications subsystem may
include
an infrared device and associated circuits and components, or a Bluetooth
communications
module to provide for communication with similarly-enabled systems and
devices.
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Many modifications and other embodiments of the invention will come to the
mind
of one skilled in the art having the benefit of the teachings presented in the
foregoing
descriptions and the associated drawings. Therefore, it is understood that the
invention is
not to be limited to the specific embodiments disclosed, and that
modifications and
embodiments are intended to be included within the scope of the appended
claims.
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