Note: Descriptions are shown in the official language in which they were submitted.
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MOBILE WIRELESS COMMUNICATIONS DEVICE HAVING AN ANTENNA ASSEMBLY
WITH CORNER COUPLED RECTANGULAR BASE CONDUCTOR PORTIONS AND
RELATED METHODS
Technical Field
[0001] The present disclosure generally relates to the field
of wireless communications systems, and, more particularly, to
mobile wireless communications devices and related methods.
Background
[0002] Mobile wireless communications systems continue to
grow in popularity and have become an integral part of both
personal and business communications. For example, cellular
telephones allow users to place and receive voice calls almost
anywhere they travel. Moreover, as cellular telephone technology
has increased, so too has the functionality of cellular devices
and the different types of devices available to users. For
example, many cellular devices now incorporate personal digital
assistant (PDA) features such as calendars, address books, task
lists, etc. Moreover, such multi-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.
[0003] Even so, 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. One challenge this poses for cellular device
manufacturers is designing antennas that provide desired
operating characteristics within the relatively limited amount
of space available for antennas.
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Brief Description of the Drawings
[0004] FIG. 1 is a top plan view of a mobile wireless
communications device including an antenna assembly in
accordance with one example embodiment.
[0005] FIG. 2 is a schematic block diagram of the device of
FIG. 1.
[0006] FIG. 3 is a side schematic view of the substrate of
the device of FIG. 1.
[0007] FIG. 4 is a graph of simulated S-parameters for the
antenna assembly of FIG. 2.
[0008] FIGS. 5a-5c are graphs of simulated gain for the
antenna assembly of FIG. 2 at a frequency of 3.2 GHz.
[0009] FIGS. 6a-6c are graphs of simulated gain for the
antenna assembly of FIG. 2 at a frequency of 7.3 GHz.
[0010] FIG. 7 is a schematic block diagram of a device
according to another example embodiment.
[0011] FIG. 8 is a schematic block diagram illustrating in
more detail components that may be included in the mobile
wireless communications device of FIG. 1.
Detailed Description
[0012] The present description is made with reference to the
accompanying drawings, in which various embodiments are shown.
However, many different embodiments may be used, and thus the
description 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.
Like numbers refer to like elements throughout, and prime
notation is used to indicate similar elements or steps in
alternative embodiments.
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[0013] In accordance with one exemplary aspect, a mobile
wireless communications device may include a portable housing, a
substrate carried by the portable housing, and wireless
communications circuitry carried by the substrate. The mobile
wireless communications device may also include at least one an
antenna assembly carried by the substrate and coupled to the
wireless communications circuitry. The at least one antenna
assembly may include an electrically conductive base conductor
having a first rectangular base portion and a second rectangular
base portion offset therefrom. The first and second base
portions may be coupled at respective diagonally opposing
corners thereof and having an antenna feed defined on one of the
first and second rectangular base portions. The at least one
antenna assembly may include at least one electrically
conductive arm extending along at least one side of one of the
first and second rectangular base portions and spaced apart
therefrom.
[0014] The at least one electrically conductive arm may
include an L-shaped conductive arm. The at least one
electrically conductive arm may be coupled to at least one of
the first and second rectangular base portions, for example.
[0015] The at least one electrically conductive arm may also
include at least one electrically floating conductive arm, for
example. The at least one electrically conductive arm may
include first and second electrically conductive arms adjacent
the first and second rectangular base portions, respectively,
for example. The at least one electrically conductive arm may
extend along at least two sides of an adjacent one of the first
and second rectangular base portions.
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[0016] The substrate may include a dielectric layer and a
conductive layer carried by the dielectric layer and define a
ground plane, for example. The at least one antenna assembly
may be above the ground plane. The at least one antenna
assembly may include a plurality of spaced apart antenna
assemblies.
[0017] A method aspect is directed to a method of making a
mobile wireless communications device that may include a
portable housing, a substrate carried by the portable housing,
and wireless communications circuitry carried by the substrate.
The method may include forming at least one antenna assembly on
the substrate and coupled to the wireless communications
circuitry. The antenna assembly may be formed by at least
forming an electrically conductive base conductor comprising a
first rectangular base portion and a second rectangular base
portion offset therefrom. The first and second base portions
may be coupled at respective diagonally opposing corners thereof
and may have an antenna feed defined on one of the first and
second rectangular base portions, for example. Forming the at
least one antenna assembly may also include forming at least one
electrically conductive arm extending along at least one side of
one of the first and second rectangular base portions and spaced
apart therefrom.
[0018] Referring initially to FIGS. 1-3, a mobile wireless
communications device 30 illustratively includes a housing 31
and a substrate 32, for example, a printed circuit board (PCB)
carried by the housing. The housing 31 has an upper portion and
a lower portion. The substrate 32 may be a rigid PCB, or may be
a flexible substrate or PCB, for example. In some embodiments
wherein a PCB is used, the PCB may be replaced by or used in
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conjunction with a metal chassis or other substrate, as will be
appreciated by those skilled in the art and described in further
detail below. The substrate 32 includes a conductive layer 36
defining the ground plane (FIG. 3). The substrate 32 also
includes a dielectric layer 37 carrying the conductive layer 36.
The substrate 32 may have additional layers, as will be
appreciated by those skilled in the art. The dielectric layer
37 has a dielectric constant of 2.25 and dimensions of 40 mm x
100 mm. Of course, the dielectric layer 37 may have another
value dielectric constant and other dimensions. The ground
plane or conductive layer 36 is carried by one side of the
dielectric layer 37 and has a smaller dimension than the
dielectric layer, for example, 40 mm x 80 mm. Of course, the
conductive layer 36 may have a different dimension, for example,
a same dimension as the dielectric layer 37.
(0019) Wireless communications circuitry 33 is carried by the
portable housing 31. The wireless communications circuitry 33
may include, for example, a wireless transceiver 35. The
wireless communications circuitry 33 may also include, in some
embodiments, a satellite positioning signal receiver 34. The
satellite positioning signal receiver 34 may be a Global
Positioning System (GPS) satellite receiver, for example. Of
course, the mobile wireless communications device 30 may not
include a satellite positioning receiver, or may include
additional receivers and/or transmitters, for example, near-
field communications (NFC) receivers and/or transmitters and
wireless local area network receivers (e.g. 802.xx, WiFi,
WiMax). The satellite positioning receiver 34 or other or
additional receivers and/or transmitters may not be part of the
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wireless communications circuitry 33, as will be appreciated by
those skilled in the art.
[0020] The exemplary device 30 further illustratively
includes a display 60 and a plurality of control keys including
an "off hook" (i.e., initiate phone call) key 61, an "on hook"
(i.e., discontinue phone call) key 62, a menu key 63, and a
return or escape key 64. Operation of the various device
components and input keys, etc., will be described further below
with reference to FIG. 8.
[0021] The device 30 further illustratively includes an
antenna assembly 40 carried by the substrate 32 and coupled to
the wireless communications circuitry 33. The antenna assembly
40 is illustratively carried by an upper portion of the portable
housing 31. Of course, the antenna assembly may be carried
elsewhere in the portable housing 31. The antenna assembly 40
may also be positioned vertically with respect to the substrate
32.
[0022] The antenna assembly 40 is a monopole antenna, and
spaced above the ground plane or conductive layer 36. The
dielectric layer 37 carries the antenna assembly 40 on one side
and the conductive layer 36 on an opposing side (FIG. 3).
Alternatively, the antenna assembly 40 may be carried on the
same side or surface of the dielectric layer 37 as the
conductive layer 36, for example. The antenna assembly 40 may
be carried elsewhere by the substrate 32. The antenna assembly
40 may be vertically or horizontally oriented with respect to
the conductive layer 36.
[0023] The antenna assembly 40 includes an electrically
conductive base conductor 41. The electrically conductive base
conductor 41 includes a first rectangular base portion 42a and a
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second rectangular base portion 42b offset from the first
rectangular base portion. The first and second base portions 42
are coupled at respective diagonally opposing corners thereof 48
and define the main radiating element.
[0024] An antenna feed point 43 is defined on the second
rectangular base portion 42b. Of course, the antenna feed point
43 may be defined on any one of the first and second rectangular
base portions 42. As will be appreciated by those skilled in
the art, positioning or defining the feed point 43 along another
portion of either of the first and second rectangular base
portions 42 may result in polarization diversity or change in
other antenna characteristics, such as, resonance frequency,
bandwidth, and gain. For example, if the antenna assembly 40 is
rotated 180 degrees and the antenna feed point 43 is defined on
the first base portion 42a, the polarization of the radiated
field would be orthogonal compared to the radiated field of the
antenna assembly without rotation.
[0025] A first L-shaped base conductor arm 45 is coupled to
the first rectangular base portion 42a at a corner diagonally
opposing the corner coupled to the second rectangular base
portion 42b. The first L-shaped conductor 45 arm being coupled
to the first rectangular base portion 42a defines an L-shaped
opening 44. Illustratively, the first L-shaped base conductor
arm 45 extends along two sides of the first rectangular base
portion 42a, and has an end 46 adjacent the coupled diagonally
opposing corners 48. The first L-shaped base conductor arm 45
advantageously may contribute to the increased bandwidth of the
antenna assembly 40, for example, from 3 GHz to 9 GHz. The
first L-shaped base conductor arm 45 also may provide additional
resonance to the antenna assembly 40.
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[0026] The antenna assembly 40 also illustratively includes a
second L-shaped electrically conductive arm 47 that is adjacent
the second rectangular base portion 42b. The second L-shaped
electrically conductive arm 47 is electromagnetically coupled to
the second rectangular base portion 42b. The second L-shaped
electrically conductive arm 47 is spaced apart from the second
rectangular base portion 42b, i.e. it is electrically floating.
The second L-shaped electrically floating conductive arm 47
extends along a side of the second rectangular base portion 42b
from a corner thereof that is diagonally opposing the corner
coupled to the first rectangular base conductor 42a. The second
L-shaped electrically floating conductive arm 47 extends along
another side of the second rectangular base portion 42b to
adjacent the diagonally opposing coupled corners 48. The second
L-shaped electrically floating conductive arm 47 advantageously
may also contribute to the increased bandwidth of the antenna
assembly 40, for example, from 3 GHz to 9 GHz. The second L-
shaped electrically floating conductive arm 47 also may provide
additional resonance to the antenna assembly 40.
[0027] While the antenna assembly 40 illustratively includes
the first L-shaped conductor arm 45 and the second L-shaped
electrically floating conductive arm 47, it will be appreciated
by those skilled in the art that the antenna assembly may
include either of the first and second L-shaped conductor arms.
Moreover, each of the L-shaped conductor arms 45, 47 may be
positioned or oriented in another configuration.
[0028] The wireless communications circuitry 33 may also
include a controller 38 or processor. The controller 38 may
cooperate with the other components, for example, the antenna
assembly 40, the satellite positioning signal receiver 34, and
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the wireless transceiver 33 to coordinate and control operations
of the mobile wireless communications device 30. Operations may
include mobile voice and data operations, including email and
Internet data.
[0029] The overall size of the antenna assembly 40 may be 12
mm x 10 mm, for example. The antenna assembly 40 may be other
sizes. The antenna assembly 40 as will be appreciated by those
skilled in the art, also has an omni-directional radiation
pattern, increased efficiency, and increased constant gain for a
relatively large bandwidth that may include the WiMax band, for
example. In other words, the antenna assembly 40 advantageously
provides nearly constant gain and increased radiation efficiency
in the operating frequency band, for example. More
particularly, the main lobe direction of the antenna assembly 40
is theta = 135 degrees, and phi = 90 degrees, while if the
antenna assembly is rotated 180 degrees, as noted above, the
main lobe direction is theta = 40 degrees, and phi = 0 degrees.
[0030] Referring now additionally to the graph 60 in FIG. 4,
a simulated S parameter plot is illustrated. The simulated S
parameter 61 of an antenna assembly similar to the antenna
assembly 40 in FIG. 2 and described above is graphed versus
frequency. The simulated S parameter 62 for an antenna assembly
without both L-shaped conductive arms 45, 47 is also
illustrated. As illustrated in the graph 60, the L-shaped
electrically conductive arms 45, 47, advantageously provide
additional resonance to the antenna assembly 40 and may increase
bandwidth at least by a factor of 7.
[0031] Referring now to the graphs 63, 64, and 65 in FIGS.
5a-5c, simulated radiation patterns for an antenna assembly
similar to the antenna assembly 40 are illustrated. The graphs
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63, 64, 65 illustrate the radiation patterns at the frequency of
3.2 GHz. Graph 63 illustrates the gain in the X-Y plane (FIG.
5a). Graph 64 illustrates the gain in the X-Z plane (FIG. 5b).
Graph 65 illustrated the gain in the Y-Z plane (FIG. 5c). The Z
axis is along the length of the substrate 32, the X axis is
along the width, and the Y axis is along the thickness. The
gain is about 5.1 dB at the frequency of 3.2 GHz.
[0032] Referring now to the graphs 66, 67, and 68 in FIGS.
6a-6c, simulated radiation patterns for an antenna assembly
similar to the antenna assembly 40 are illustrated. The graphs
66, 67, 68 illustrate the radiation patterns at the frequency of
7.3 GHz. Graph 66 illustrates the gain in the X-Y plane (FIG.
6a). Graph 67 illustrates the gain in the X-Z plane (FIG. 6b).
Graph 68 illustrated the gain in the Y-Z plane (FIG. 6c). The Z
axis is along the length of the substrate 32, the X axis is
along the width, and the Y axis is along the thickness. The
gain is about 5.1 dB at the frequency of 7.3 GHz.
[0033] Moreover, based upon the relatively small size of the
antenna assembly 40, in other example embodiments, the antenna
assembly 40 may be carried by a flexible substrate (not shown).
The flexible substrate may be included with the substrate 32,
for example, for carrying other components or circuitry, for
example, the display 60, the wireless communications circuitry
33, and the satellite positioning signal receiver 34. The
flexible substrate may advantageously allow for conforming of
the antenna assembly 40 with the back of the portable housing
31. The flexible substrate may include an adhesive layer (not
shown), for example, a pressure sensitive adhesive, on an
underside thereof for mounting. A copper layer (not shown) may
be carried on a front side of the flexible substrate.
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[0034] Referring now to FIG. 7, in another example
embodiment, the mobile wireless communications device 30'
includes two antenna assemblies 40', 50'. Each antenna assembly
40', 50' is spaced apart and carried at the top portion of the
portable housing 31'. Of course, each antenna assembly 40', 50'
may be carried by a different portion of the portable housing
31'. The first and second antenna assemblies 40', 50' are
illustratively similar to the antenna assembly 40 described
above and illustrated in FIG. 2, for example. The second
antenna assembly 50' is also illustratively the same as the
first antenna assembly 40' in that it includes an electrically
conductive base conductor 51' including first an second
rectangular base portions 52a', 52b' coupled at respective
diagonally opposing corners thereof 58', an antenna feed 53'
defined in the second rectangular base portion, and first and
second L-shaped conductive arms 55', 57', extending along the
first and second rectangular base portions, respectively, and in
the same configuration. Of course, the first and second antenna
assemblies 40', 50' may have different configurations and have
more or less components relative to one another.
[0035] In addition to spatial diversity, as noted above,
polarization diversity may also be accomplished by using the two
antenna assemblies 40', 50'. More particularly, polarization
diversity may be achieved by rotating one of the first and
second antenna assemblies 40', 50' 180 degrees, and feeding that
antenna assembly from the respective first rectangular base
portion 42a', 52a'. The relatively small size of each antenna
assembly 40', 50' may make it particularly advantageous in
multiple-input and multiple-output (MIMO) systems, for example.
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[0036] A method aspect is directed to a method of making a
mobile wireless communications device 30 that may include a
portable housing 31, a substrate 32 carried by the portable
housing, and wireless communications circuitry 33 carried by the
substrate. The method includes forming an antenna assembly 40
on the substrate 32 and coupled to the wireless communications
circuitry 33. Forming the antenna assembly 40 includes forming
an electrically conductive base conductor 41 comprising a first
rectangular base portion 42a and a second rectangular base
portion 42b offset therefrom. The first and second base
portions 42 are coupled at respective diagonally opposing
corners thereof and have an antenna feed 43 defined on one of
the first and second base portions 42. Forming the antenna
assembly 40 also includes forming an electrically conductive arm
45, 47 extending along at least one side of one of the first and
second rectangular base portions 42 and spaced apart therefrom.
[0037] Example components of a mobile wireless communications
device 1000 that may be used in accordance with the above-
described embodiments are further described below with reference
to FIG. 8. The device 1000 illustratively includes a housing
1200, a keyboard or keypad 1400 and an output device 1600. The
output device shown is a display 1600, which may comprise 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 keypad 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
keypad 1400.
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[0038] The housing 1200 may be elongated vertically, or may
take on other sizes and shapes (including clamshell housing
structures). The keypad may include a mode selection key, or
other hardware or software for switching between text entry and
telephony entry.
[0039] In addition to the processing device 1800, other parts
of the mobile device 1000 are shown schematically in FIG. 8.
These include a communications subsystem 1001; a short-range
communications subsystem 1020; the keypad 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 may comprise a
two-way RF communications device having data and, optionally,
voice communications capabilities. In addition, the mobile
device 1000 may have the capability to communicate with other
computer systems via the Internet.
[0040] Operating system software executed by the processing
device 1800 is 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.
[0041] 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 communications 1300A and 1300B, may be installed
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on the device 1000 during manufacture. In addition, a personal
information manager (PIM) application may be installed during
manufacture. The PIM may be capable of organizing and managing
data items, such as e-mail, calendar events, voice mails,
appointments, and task items. The PIM application may also be
capable of sending and receiving data items via a wireless
network 1401. The PIM data items may be seamlessly integrated,
synchronized and updated via the wireless network 1401 with
corresponding data items stored or associated with a host
computer system.
[0042] 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, WCDMA, PCS, GSM, EDGE, etc. Other
types of data and voice networks, both separate and integrated,
may also be utilized with the mobile device 1000. The mobile
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device 1000 may also be compliant with other communications
standards such as 3GSM, 3GPP, UMTS, 4G, etc.
[0043] 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 typically involves use of a subscriber identity
module, commonly referred, to as a SIM card, in order to operate
on a GPRS network.
[0044] 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 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.
[0045] 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
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signals in the receiver 1500 and transmitter 1520 may be
adaptively controlled through automatic gain control algorithms
implemented in the DSP 1580.
[0046] 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
may also be used to compose data items, such as e-mail messages,
using the keypad 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.
[0047] 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.
[0048] 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
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components, a BluetoothTM communications module to provide for
communication with similarly-enabled systems and devices, or a
near field communications (NFC) sensor for communicating with a
NFC device or NFC tag via NFC communications.
[0049] 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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