U.S. patent application number 16/241614 was filed with the patent office on 2019-08-22 for methods for reducing radiated emissions from power amplifiers.
The applicant listed for this patent is Skyworks Solutions, Inc.. Invention is credited to Grant Darcy Poulin.
Application Number | 20190260403 16/241614 |
Document ID | / |
Family ID | 58407301 |
Filed Date | 2019-08-22 |
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United States Patent
Application |
20190260403 |
Kind Code |
A1 |
Poulin; Grant Darcy |
August 22, 2019 |
METHODS FOR REDUCING RADIATED EMISSIONS FROM POWER AMPLIFIERS
Abstract
Apparatus and methods for orienting power amplifiers are
disclosed herein. In certain implementations, a method of
determining the physical orientation of power amplifiers laid out
on a printed circuit board (PCB) is provided. The method includes
determining an amount of emissions radiated by a first power
amplifier die that is positioned in a first orientation on the PCB.
The method further includes determining an amount of emissions
radiated by a second power amplifier die that is positioned in a
second orientation on the PCB. The method further includes
determining a third orientation of the second power amplifier die
different than the second orientation, such that when the second
power amplifier die is in the third orientation, the amount of
emissions radiated by the first power amplifier die and the amount
of emissions radiated by the second power amplifier die are
distributed in different directions.
Inventors: |
Poulin; Grant Darcy; (Carp,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Skyworks Solutions, Inc. |
Woburn |
MA |
US |
|
|
Family ID: |
58407301 |
Appl. No.: |
16/241614 |
Filed: |
January 7, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15280153 |
Sep 29, 2016 |
10211862 |
|
|
16241614 |
|
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62235320 |
Sep 30, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 2119/06 20200101;
H05K 3/0005 20130101; H04B 2001/045 20130101; H03F 2200/451
20130101; H05K 2201/10166 20130101; G06F 30/367 20200101; H05K
2201/10522 20130101; H04B 17/13 20150115; H05K 1/181 20130101; H03F
1/02 20130101; G06F 30/392 20200101; H03F 2201/3215 20130101; H03F
1/0277 20130101; H03F 2203/7221 20130101; H03F 2200/114 20130101;
H04B 1/0475 20130101; H03F 3/211 20130101; H05K 2201/10098
20130101; H03F 3/68 20130101; H03F 3/245 20130101; H03F 1/32
20130101; H03F 3/24 20130101; H03F 3/72 20130101; H03F 3/19
20130101; G06F 2119/10 20200101; H03F 2203/7236 20130101 |
International
Class: |
H04B 1/04 20060101
H04B001/04; H03F 1/02 20060101 H03F001/02; H03F 3/24 20060101
H03F003/24; H03F 1/32 20060101 H03F001/32; H05K 3/00 20060101
H05K003/00; H04B 17/13 20060101 H04B017/13; H03F 3/19 20060101
H03F003/19; H03F 3/68 20060101 H03F003/68; H03F 3/72 20060101
H03F003/72; G06F 17/50 20060101 G06F017/50; H05K 1/18 20060101
H05K001/18; H03F 3/21 20060101 H03F003/21 |
Claims
1. A method of determining the physical orientation of power
amplifiers laid out on a printed circuit board comprising:
determining an amount of emissions radiated by a first power
amplifier die that is positioned in a first orientation on the
printed circuit board; determining an amount of emissions radiated
by a second power amplifier die that is positioned in a second
orientation on the printed circuit board; and determining a third
orientation of the second power amplifier die different than the
second orientation, such that when the second power amplifier die
is in the third orientation, the amount of emissions radiated by
the first power amplifier die and the amount of emissions radiated
by the second power amplifier die are distributed in different
directions.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/280,153, filed Sep. 29, 2016 and titled
"METHODS FOR REDUCING RADIATED EMISSIONS FROM POWER AMPLIFIERS,"
which claims the benefit of priority under 35 U.S.C. .sctn. 119(e)
of U.S. Provisional Patent Application No. 62/235,320, filed Sep.
30, 2015 and titled "APPARATUS AND METHODS FOR REDUCING RADIATED
EMISSIONS FROM POWER AMPLIFIERS," which are hereby incorporated by
reference herein in their entireties.
BACKGROUND
Field
[0002] Embodiments of the invention relate to electronic systems,
and in particular, to power amplifiers for radio frequency (RF)
electronics.
Description of the Related Technology
[0003] Power amplifiers can be included in fixed and mobile devices
to amplify radio frequency (RF) signals for transmission via
antennas. For example, in devices using the WLAN IEEE 802.11
standard (commonly referred to as WI-FI), such as the IEEE 802.11ac
standard, a power amplifier can be used to provide amplification to
one or more transmit carrier frequencies.
[0004] Many mobile devices operate in the currently unlicensed
frequency bands of 2.4 GHz (e.g., about 2.39 GHz to 2.4835 GHz) and
5 GHz (e.g., about 5.25 GHz to 5.35 GHz and about 5.46 GHz to 5.85
GHz). However, the Federal Communications Commission (FCC) has
mandated very stringent emissions requirements for certain
restricted frequency bands, such as 4.5 GHz to 5.25 GHz and 10.6
GHz to 12.7 GHz.
SUMMARY
[0005] These restricted frequency bands can be of relevance to
mobile devices that operate in the unlicensed frequency bands
because the second harmonic spectral content generated by power
amplifiers operating in the unlicensed frequency bands may fall in
the restricted frequency bands. Thus, managing the emissions
radiated by power amplifiers operating in the unlicensed frequency
bands is important.
[0006] In certain embodiments, the present disclosure relates to a
method of determining the physical orientation of power amplifiers
laid out on a printed circuit board. The method comprises
determining an amount of emissions radiated by a first power
amplifier die that is positioned in a first orientation on the
printed circuit board; determining an amount of emissions radiated
by a second power amplifier die that is positioned in a second
orientation on the printed circuit board; and determining a third
orientation of the second power amplifier die different than the
second orientation, such that when the second power amplifier die
is in the third orientation, the amount of emissions radiated by
the first power amplifier die and the amount of emissions radiated
by the second power amplifier die are distributed in different
directions.
[0007] The method of the preceding paragraph can have any
sub-combination of the following features: where an output of the
first power amplifier die faces a first direction and the emissions
radiated by the first power amplifier die are radiated in the first
direction; where the third orientation of the second power
amplifier die includes an output of the second power amplifier die
facing a second direction different than the first direction; where
the method further comprises determining an amount of emissions
radiated by a first antenna coupled to the first power amplifier
die; where determining a third orientation of the second power
amplifier die includes determining the orientation of the second
power amplifier die such that the amount of emissions radiated by
the first power amplifier die, the amount of emissions radiated by
the second power amplifier die, and the amount of emissions
radiated by the first antenna die are distributed in different
directions; where the method further comprises determining an
adjusted orientation of the first antenna such that the amount of
emissions radiated by the first power amplifier die, the second
power amplifier die, or the first antenna in a first direction is
less than a threshold value; where determining a third orientation
of the second power amplifier die includes determining the third
orientation of the second power amplifier die such that the amount
of emissions radiated by the first power amplifier die or the
second power amplifier die in a first direction is less than a
threshold value; where the first and second power amplifier dies
are physical devices laid out on the printed circuit board; where
determining an amount of emissions radiated by a first power
amplifier die and determining an amount of emissions radiated by a
second power amplifier die both include measuring the amount of
emissions using a sensor; where determining an adjusted orientation
of the second power amplifier die includes physically adjusting the
orientation of the second power amplifier die from the second
orientation to the third orientation, and measuring an amount
emissions radiated by the second power amplifier die when in the
third orientation using the sensor; where the first and second
power amplifier dies are simulated power amplifier dies
instantiated in a software circuit simulator; where the determining
an amount of emissions radiated by a first power amplifier die and
determining an amount of emissions radiated by a second power
amplifier die both include using the software circuit simulator to
simulate an amount of emissions; where determining an adjusted
orientation of the second power amplifier die includes using the
software circuit simulator to simulate a change in the orientation
of the second power amplifier die from the second orientation to
the third orientation, and using the software circuit simulator to
measure an amount emissions radiated by the second power amplifier
die when in the third orientation; where each of the first and
second power amplifier dies include a single power amplifier; and
where one or more of the first and second power amplifier dies
include multiple power amplifiers.
[0008] In certain embodiments, the present disclosure relates to a
method of determining the physical orientation of power amplifiers
laid out on a printed circuit board. The method comprises
determining an amount of emissions radiated by a first power
amplifier die that is positioned in a first orientation on the
printed circuit board; determining an amount of emissions radiated
by a second power amplifier die that is positioned in a second
orientation on the printed circuit board; determining whether the
amount of emissions radiated by the first power amplifier die in a
first direction and the amount of emissions radiated by the second
power amplifier die in the first direction exceed a threshold
value; determining a third orientation of the second power
amplifier die different than the second orientation in response to
a determination that the amount of emissions radiated by the first
power amplifier die in the first direction and the amount of
emissions radiated by the second power amplifier die in the first
direction exceed the threshold value, such that the amount of
emissions radiated by the first power amplifier die in the first
direction while in the first orientation and the amount of
emissions radiated by the second power amplifier die in the first
direction while in the third orientation are below the threshold
value; and adjusting an orientation of the second power amplifier
die from the second orientation to the third orientation.
[0009] The method of the preceding paragraph can have any
sub-combination of the following features: where the third
orientation of the second power amplifier die includes an output of
the second power amplifier die facing a second direction different
than the first direction; and where adjusting an orientation of the
second power amplifier die from the second orientation to the third
orientation includes de-soldering the second power amplifier die
from the printed circuit board and re-soldering the second power
amplifier due to the printed circuit board in the third
orientation.
[0010] In certain embodiments, the present disclosure relates to a
non-transitory computer-readable medium having stored thereon a
simulation application configured to run on a computing system. The
simulation application comprises executable program code that
directs the computing device to implement a process comprising
determining an amount of emissions radiated by a first power
amplifier die that is positioned in a first orientation on a
simulated printed circuit board; determining an amount of emissions
radiated by a second power amplifier die that is positioned in a
second orientation on the simulated printed circuit board;
determining whether the amount of emissions radiated by the first
power amplifier die in a first direction and the amount of
emissions radiated by the second power amplifier die in the first
direction exceed a threshold value; adjusting an orientation of the
second power amplifier die to a third orientation different than
the second orientation in response to a determination that the
amount of emissions radiated by the first power amplifier die in
the first direction and the amount of emissions radiated by the
second power amplifier die in the first direction exceed the
threshold value; and in response to a determination that the amount
of emissions radiated by the first power amplifier die in the first
direction while in the first orientation and the amount of
emissions radiated by the second power amplifier in the first
direction while in the third orientation exceed the threshold
value, continuing to adjust an orientation of the second power
amplifier due until the amount of emissions radiated by the first
power amplifier die in the first direction and the amount of
emissions radiated by the second power amplifier die in the first
direction is below the threshold value.
[0011] The non-transitory computer-readable medium of the preceding
paragraph can have any sub-combination of the following features:
where the process includes generating a file that instructs a
soldering machine to orient the first power amplifier die in the
first orientation on an actual printed circuit board and to orient
the second power amplifier die in the third orientation on the
actual printed circuit board.
[0012] In certain embodiments, the present disclosure relates to a
power amplifier system. The power amplifier system comprises a
first power amplifier die that is positioned in a first orientation
on a printed circuit board and configured to radiate a first amount
of emissions; a second power amplifier die that is positioned in a
second orientation on the printed circuit board and configured to
radiate a second amount of emissions, the second orientation
differing from the first orientation by a first angle; and a third
power amplifier die that is positioned in a third orientation on
the printed circuit board and configured to radiate a third amount
of emissions, the third orientation differing from the first
orientation by a second angle different from the first angle, the
third orientation differing from the second orientation by a third
angle different from the first and second angles, the third power
amplifier die oriented such that the first amount of emissions, the
second amount of emissions, and the third amount of emissions in a
first direction are less than a threshold value.
[0013] The power amplifier system of the preceding paragraph can
have any sub-combination of the following features: where an output
of the first power amplifier die faces the first direction and the
emissions radiated by the first power amplifier die are radiated in
the first direction; where the third power amplifier die is
oriented such that an output of the third power amplifier die faces
a second direction different than the first direction; where the
power amplifier system further comprises a first antenna coupled to
the first power amplifier die, the first antenna configured to
radiate a fourth amount of emissions; where the third power
amplifier die is oriented such that the first amount of emissions,
the second amount of emissions, the third amount of emissions, and
the fourth amount of emissions in the first direction are less than
the threshold value; where the first antenna is oriented such that
the first amount of emissions, the second amount of emissions, the
third amount of emissions, and the fourth amount of emissions in
the first direction are less than the threshold value; and where an
output of the first power amplifier die faces the first direction,
the output of the third power amplifier die facing a second
direction that is a 45 degree angle from an axis that runs along
the first direction.
[0014] In certain embodiments, the present disclosure relates to a
wireless device. The wireless device comprises a transceiver
configured to generate a first radio frequency signal and a second
radio frequency signal; a first power amplifier die that is
positioned in a first orientation and configured to amplify the
first radio frequency signal, the first power amplifier die
configured to radiate a first amount of emissions; a second power
amplifier die that is positioned in a second orientation and
configured to amplify the second radio frequency signal, the second
orientation differing from the first orientation by a first angle,
the second power amplifier die configured to radiate a second
amount of emissions, the second power amplifier die oriented such
that the first amount of emissions and the second amount of
emissions in a first direction are less than a threshold value; a
first antenna coupled to the first power amplifier die and
configured to transmit the amplified first radio frequency signal;
and a second antenna coupled to the second power amplifier die and
configured to transmit the amplified second radio frequency
signal.
[0015] The wireless device of the preceding paragraph can have any
sub-combination of the following features: where an output of the
first power amplifier die faces the first direction and the
emissions radiated by the first power amplifier die are radiated in
the first direction; where the second power amplifier die is
oriented such that an output of the second power amplifier die
faces a second direction different than the first direction; where
the first antenna is configured to radiate a third amount of
emissions; where the second power amplifier die is oriented such
that the first amount of emissions, the second amount of emissions,
and the third amount of emissions in the first direction are less
than the threshold value; where the first antenna is oriented such
that the first amount of emissions, the second amount of emissions,
and the third amount of emissions in the first direction are less
than the threshold value.
[0016] In certain embodiments, the present disclosure relates to a
wireless device. The wireless device comprises a transceiver
configured to generate a first radio frequency signal; a power
amplifier die configured to amplify the first radio frequency
signal, the power amplifier die including a first power amplifier
circuit and a second power amplifier circuit, the first power
amplifier circuit positioned in a first orientation in the power
amplifier die and configured to radiate a first amount of
emissions, the second power amplifier circuit positioned in a
second orientation in the power amplifier die and configured to
radiate a second amount of emissions, the second orientation
differing from the first orientation by a first angle, the second
power amplifier circuit oriented such that the first amount of
emissions and the second amount of emissions in a first direction
are less than a threshold value; and an antenna coupled to the
power amplifier die and configured to transmit the amplified first
radio frequency signal.
[0017] The wireless device of the preceding paragraph can have any
sub-combination of the following features: where an output of the
first power amplifier circuit faces the first direction and the
emissions radiated by the first power amplifier circuit are
radiated in the first direction; where the second power amplifier
circuit is oriented such that an output of the second power
amplifier circuit faces a second direction different than the first
direction; where the antenna is configured to radiate a third
amount of emissions; where the second power amplifier circuit is
oriented such that the first amount of emissions, the second amount
of emissions, and the third amount of emissions in the first
direction are less than the threshold value; where the wireless
device further comprises a second power amplifier die, the second
power amplifier die including a third power amplifier circuit and a
fourth power amplifier circuit, the third power amplifier circuit
positioned in the first orientation in the second power amplifier
die and configured to radiate a third amount of emissions, the
fourth power amplifier circuit positioned in a third orientation in
the second power amplifier die and configured to radiate a fourth
amount of emissions, the third orientation differing from the first
orientation by a second angle different from the first angle, the
third orientation differing from the second orientation by a third
angle different from the first and second angles; and where the
second power amplifier circuit is oriented such that the first
amount of emissions, the second amount of emissions, the third
amount of emissions, and the fourth amount of emissions in the
first direction are less than the threshold value.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic diagram of a power amplifier module
for amplifying a radio frequency (RF) signal.
[0019] FIG. 2 is a schematic diagram of an example wireless device
that can include one or more of the power amplifier modules of FIG.
1.
[0020] FIG. 3 is a side view of a power amplifier, such as the
power amplifier of FIG. 2.
[0021] FIG. 4 illustrates another schematic block diagram of an
example wireless or mobile device.
[0022] FIGS. 5A-5E illustrates another schematic block diagram of
the example wireless of mobile device illustrated in FIG. 4.
[0023] FIG. 6 illustrates an example flowchart of a process for
determining the physical orientation of power amplifiers laid out
on the PCB of a wireless device, such as the wireless device of
FIG. 2 and/or the wireless device of FIGS. 4 and 5A-5E.
[0024] FIG. 7 illustrates another example flowchart of a process
for determining the physical orientation of power amplifiers laid
out on the PCB of a wireless device, such as the wireless device of
FIG. 2 and/or the wireless device 400 of FIGS. 4-5E.
DETAILED DESCRIPTION OF EMBODIMENTS
[0025] The headings provided herein, if any, are for convenience
only and do not necessarily affect the scope or meaning of the
claimed invention.
[0026] As described above, certain inventive aspects described
herein are based on the realization that managing the emissions
radiated by power amplifiers that operate in unlicensed frequency
bands (e.g., about 2.39 GHz to 2.4835 GHz, about 5.25 GHz to 5.35
GHz, and about 5.46 GHz to 5.85 GHz) may be important because the
second harmonic spectral content generated by power amplifiers
operating in the unlicensed frequency bands may fall in restricted
frequency bands (e.g., 4.5 GHz to 5.25 GHz and 10.6 GHz to 12.7
GHz). This may be especially true for mobile devices that implement
a multi-input and multi-output (MIMO) configuration. In a MIMO
configuration, a mobile device may have as many eight power
amplifiers that operate concurrently or simultaneously. Given the
number of concurrently operating power amplifiers, managing
emissions can help improve protection against the amount of
radiated second harmonic emissions resulting in FCC regulatory
failures.
[0027] Generally, emissions radiated by power amplifiers are
reduced via RF shielding or absorbers. For example, a power
amplifier can be enclosed within a case made of conductive or
magnetic materials that reduce harmonic radiated emissions. As
another example, an RF absorber (e.g., tuned to a resonant
frequency) made of rubber, dielectric foam, and/or the like can be
coupled to a power amplifier (or placed in proximity to the power
amplifier) to absorb frequencies within a narrow frequency band.
However, RF shields and absorbers can be expensive and/or may
occupy valuable space on a circuit board, thereby resulting in the
circuit board being a larger size than would otherwise be
necessary.
[0028] It was generally assumed that a power amplifier would
generate harmonics, the harmonics would travel via the transmission
lines to the RF antenna, and the RF antenna would directly radiate
the emissions. However, matching structures inside the power
amplifier can be efficient radiators and can produce larger
radiated signals than the RF antennas. For example, bondwires
and/or resonant structures that couple the output transistor of a
power amplifier to the output matching network radiate at the
second harmonic frequency. The radiation pattern from these
structures is often anisotropic, meaning that the emissions
generally radiate strongly in one direction. Thus, in the MIMO
configuration, if the multiple power amplifiers are placed in
parallel and/or in close proximity to each other, there can be some
risk that radiated emissions can add together (because the
emissions radiate in the same direction) and the net radiated
emissions may exceed FCC regulatory limits.
[0029] Accordingly, in certain embodiments, an arrangement of power
amplifiers is provided herein to reduce the emissions radiated in
any given direction. One or more power amplifiers can be packaged
in a single, discrete chip or die that can be placed on a printed
circuit board (PCB). Alternatively or in addition, a power
amplifier can be unpackaged such that the transistors, resistors,
capacitors, inductors, etc. that form the power amplifier can be
individually soldered to the PCB. For simplicity, the term "power
amplifier" is used herein to refer both to a chip or die that
includes one or more power amplifiers and to the grouping of
individual circuit components that form a power amplifier (e.g., a
power amplifier circuit). The techniques described herein may be
implemented on any PCB that includes a plurality of power
amplifiers. The power amplifiers may each be physically rotated in
a manner that distributes the radiated emissions in different
directions. Arranging the power amplifiers in a way that spreads
out the radiated emissions may be beneficial because the FCC
requires users to scan for emissions radiated over an entire sphere
and report the peak emission level. By distributing the emissions
in different directions, the detected (and thus reported) peak
emission levels can be lower as the emissions are not concentrated
in one particular direction. Thus, a mobile device that includes
multiple power amplifiers may still meet FCC requirements.
[0030] FIG. 1 is a schematic diagram of a power amplifier module
(PAM) 10 for amplifying a radio frequency (RF) signal. The
illustrated power amplifier module 10 amplifies an RF signal
(RF_IN) to generate an amplified RF signal (RF_OUT). As described
herein, the power amplifier module 10 can include one or more power
amplifiers.
[0031] FIG. 2 is a schematic block diagram of an example wireless
or mobile device 11 that can include one or more of the power
amplifier modules 10 of FIG. 1, represented as power amplifiers 17a
and 17b.
[0032] The example wireless device 11 depicted in FIG. 2 can
represent a wireless access point, or a mobile device such as a
multi-band/multi-mode mobile phone. By way of example, WLAN devices
operate in many regions of the world, and operate in either the
2.4-2.5 GHz or 5-6 GHz frequency bands. Power amplifiers that
operate in these bands are generally designed to achieve very high
degrees of linearity.
[0033] One or more features of the present disclosure can be
implemented in the foregoing example modes and/or bands, and in
other communication standards. For example, IEEE 802.11 (e.g., IEEE
802.11ac), 2G, 3G, 4G, Long Term Evolution (LTE), and Advanced LTE
are non-limiting examples of such standards. To increase data
rates, the wireless device 11 can operate using complex modulated
signals, such as 64 QAM signals.
[0034] In certain embodiments, the wireless device 11 can include
switches 12, a transceiver 13, an antenna 14, power amplifiers 17a,
17b, a control component 18, a computer readable medium 19, a
processor 20, and a power supply unit 21. While only one antenna 14
is illustrated in FIG. 2, this is not meant to be limiting. The
wireless device 11 may include any number of antennas 14 (to, for
example, implement a MIMO configuration).
[0035] The transceiver 13 can generate RF signals for transmission
via the antenna 14. Furthermore, the transceiver 13 can receive
incoming RF signals from the antenna 14.
[0036] It will be understood that various functionalities
associated with the transmission and receiving of RF signals can be
achieved by one or more components that are collectively
represented in FIG. 2 as the transceiver 13. For example, a single
component can be configured to provide both transmitting and
receiving functionalities. In another example, transmitting and
receiving functionalities can be provided by separate
components.
[0037] Similarly, it will be understood that various antenna
functionalities associated with the transmission and receiving of
RF signals can be achieved by one or more components that are
collectively represented in FIG. 2 as the antenna 14. For example,
a single antenna can be configured to provide both transmitting and
receiving functionalities. In another example, transmitting and
receiving functionalities can be provided by separate antennas. In
yet another example, different bands associated with the wireless
device 11 can operate using different antennas. In yet another
example, the same signal can be transmitted and received by
separate antennas (e.g., using precoding techniques, spatial
multiplexing techniques, diversity coding techniques, etc.).
[0038] In FIG. 2, one or more output signals from the transceiver
13 are depicted as being provided to the antenna 14 via one or more
transmission paths 15. In the example shown, different transmission
paths 15 can represent output paths associated with different bands
and/or different power outputs. For instance, the two example power
amplifiers 17a, 17b shown can represent amplifications associated
with different power output configurations (e.g., low power output
and high power output), and/or amplifications associated with
different bands. Although FIG. 2 illustrates a configuration using
two transmission paths 15 and two power amplifiers 17a, 17b, the
wireless device 11 can be adapted to include more or fewer
transmission paths 15 and/or more or fewer power amplifiers.
Furthermore, while the power amplifiers 17a, 17b are illustrated as
facing the same direction, this is not meant to be limiting. The
power amplifiers 17a, 17b may be physically rotated in different
directions (e.g., to face different edges of the wireless device
11) to distribute the emissions radiated by each power amplifier
17a, 17b, as described in greater detail herein.
[0039] The antenna 14 can receive a signal that is provided to the
transceiver 13 and can transmit a signal provided by the power
amplifiers 17a, 17b. The switches 12 can be configured to
facilitate switching between a receive mode (e.g., a signal
received by the antenna 14 is provided to the transceiver 13) and a
transmit mode (e.g., a signal is provided to the antenna 14 for
transmission).
[0040] FIG. 2 shows that in certain embodiments, a control
component 18 can be provided for controlling various control
functionalities associated with operations of the switches 12, the
power amplifiers 17a, 17b, and/or other operating components.
[0041] In certain embodiments, a processor 20 can be configured to
facilitate implementation of various processes described herein.
The processor 20 can implement various computer program
instructions. The processor 20 can be a general purpose computer,
special purpose computer, or other programmable data processing
apparatus.
[0042] In certain embodiments, these computer program instructions
may also be stored in a computer-readable memory 19 that can direct
the processor 20 to operate in a particular manner, such that the
instructions stored in the computer-readable memory 19.
[0043] The power supply unit 21 can be any regulator or suitable
battery for use in the wireless device 11. For example, the power
supply unit 21, if a regulator, can be configured to supply one of
a plurality of discrete supply voltages (e.g., either 3.3V or 5V).
The power supply unit 21, if a battery, such as a lithium-ion
battery, can supply a range of supply voltages (e.g., from 2.7V to
4.6V). If the power supply unit 21 is a battery, the power consumed
from the power supply unit 21 can be reduced to improve the battery
life of the wireless device 11. In certain configurations, the
power amplifiers 17a, 17b can be implemented using CMOS processing,
which can lower cost and/or enhance integration. However, other
configurations of the power amplifiers 17a, 17b are possible. For
example, the power amplifiers 17a, 17b can be implemented using
III-V semiconductor processing, such as Gallium Arsenide (GaAs)
processing.
[0044] Power amplifiers can be included in radio frequency systems
to amplify a wireless local area network (WLAN) signal for
transmission. For example, certain wireless devices can communicate
using not only cellular standards, but also using other
communication standards, including, for example, a WLAN standard
such as WI-FI or IEEE 802.11 (e.g., IEEE 802.11ac), as described
herein.
[0045] FIG. 3 is a side view of the power amplifier 17a of FIG. 2.
As illustrated in FIG. 3, the power amplifier 17a has an input,
represented by RF.sub.IN, and an output, represented by RF.sub.OUT.
Generally, emissions 310 produced by the power amplifier 17a are
radiated in a direction toward the output. In some embodiments, the
emissions 310 are radiated away from the top of the power amplifier
17a toward the output RF.sub.OUT at about a 45 degree angle (e.g.,
between about 35 degrees and 55 degrees) from an axis 320 that
vertically passes through the power amplifier 17a. The emissions
310 may also radiate toward the output RF.sub.OUT at an angle
(e.g., 45 degrees or less) from an axis 330 that passes through the
input RF.sub.IN and the output RF.sub.OUT. Thus, if a plurality of
power amplifiers are placed in parallel with each having an output
that faces the same direction, then the emissions from each power
amplifier may be radiated in a direction as illustrated in FIG.
3.
[0046] FIG. 4 illustrates another schematic block diagram of an
example wireless or mobile device 400. The wireless device 400 as
illustrated in FIG. 4 includes fewer components than the wireless
device 11 as illustrated in FIG. 1 merely for simplicity. The
wireless device 400 may include any of the components illustrated
or described with respect to the wireless device 11.
[0047] As illustrated in FIG. 4, the wireless device 400 includes a
transceiver 402, RF antennas 405A-N, and power amplifiers 410A-N.
Thus, the wireless device 400 may be in a MIMO configuration or any
other configuration that includes multiple power amplifiers and/or
multiple antennas. In some embodiments, the power amplifiers 410A-N
are arranged in parallel and facing the same direction such that an
output of each power amplifier 410A-N is directed toward the input
of each respective antenna 405A-N. Thus, emissions 412A-N generated
by each respective power amplifier 410A-N may be aggregated and
could exceed FCC regulatory limits.
[0048] FIGS. 5A-5E illustrate another schematic block diagram of
the example wireless or mobile device 400 illustrated in FIG. 4. In
particular, FIGS. 5A-5E illustrate the placement of components of
the wireless device 400 on a PCB when looking at the wireless
device 400 from a top-down view. In FIG. 5A, the power amplifiers
410A-N are placed on the PCB and have been physically rotated to
distribute the emissions 412A-N radiated by each power amplifier
410A-N. For example, the power amplifier 410A has been placed on
the PCB such that the power amplifier 410A is parallel with a
bottom and top edge of the wireless device 400. The output of the
power amplifier 410A faces the right edge of the wireless device
400 (e.g., the output of the power amplifier 410A is oriented at an
angle of 0 degrees on the x-y axis) and thus emissions 412A
radiated by the power amplifier 410A are radiated toward the right
edge of the wireless device 400.
[0049] The power amplifier 410B has been placed on the PCB such
that the power amplifier 410B is parallel with a left and right
edge of the wireless device 400, rotated at an angle 90 degrees
from the placement of the power amplifier 410A along an axis that
traverses the horizontal length of the wireless device 400 when
looking at the wireless device 400 from a top-down view. The output
of the power amplifier 410B faces the bottom edge of the wireless
device 400 (e.g., the output of the power amplifier 410B is
oriented at an angle of 270 degrees on the x-y axis) and thus
emissions 412B radiated by the power amplifier 410B are radiated
toward the bottom edge of the wireless device 400.
[0050] The power amplifier 410C has been placed on the PCB such
that the power amplifier 410C is about 50 degrees from an axis that
is parallel with the bottom and top edge of the wireless device
400. The output of the power amplifier 410C is directed toward the
top-right corner of the wireless device 400 (e.g., the output of
the power amplifier 410C is oriented at an angle of 50 degrees on
the x-y axis) and thus emissions 412C radiated by the power
amplifier 410C are radiated toward the top-right corner of the
wireless device 400.
[0051] The power amplifier 410N has been placed on the PCB such
that the power amplifier 410N is about 30 degrees from an axis that
is parallel with the left and right edge of the wireless device
400. The output of the power amplifier 410N is directed toward the
top of the wireless device 400 at an angle of about 30 degrees from
an axis that is parallel with the left and right edge of the
wireless device 400 (e.g., the output of the power amplifier 410N
is oriented at an angle of 120 degrees on the x-y axis) and thus
emissions 412D are radiated in the same general direction.
[0052] In FIG. 5B, the power amplifiers 410A-N are placed on the
PCB and have been physically rotated in a different manner than
illustrated in FIG. 5A to distribute the emissions 412A-N radiated
by each power amplifier 410A-N. For example, the power amplifier
410A has been placed on the PCB in an orientation similar to the
orientation illustrated in FIG. 5A. The power amplifier 410B,
however, has been placed on the PCB such that the power amplifier
410B is oriented in the same direction as the power amplifier 410A
(e.g., the output of the power amplifier 410B is oriented at an
angle of 0 degrees on the x-y axis). Thus, emissions 412B radiated
by the power amplifier 410B are radiated toward the same direction
as the emissions 412A radiated by the power amplifier 410A. The
power amplifiers 410A-B may be oriented in the same direction
because, for example, the aggregated emissions 412A-B do not exceed
the FCC regulatory limits.
[0053] As described herein, one or more power amplifiers can be
packaged in a chip or die. As illustrated in FIG. 5C, two power
amplifiers are packaged in the power amplifier die 410A and two
power amplifiers are packaged in the power amplifier die 410B. The
power amplifier dies 410A, 410B can be rotated in a manner as
described herein to distribute the emissions 412A, 412B. For
example, the output of the power amplifier die 410A can be oriented
to face the right edge of the wireless device 400 (e.g., the output
of the power amplifier die 410A is oriented at an angle of 0
degrees on the x-y axis) and the output of the power amplifier die
410B can be oriented to face the bottom edge of the wireless device
400 (e.g., the output of the power amplifier die 410B is oriented
at an angle of 270 degrees on the x-y axis). Thus, the emissions
412A can be distributed toward the right edge of the wireless
device 400 and the emissions 412B can be distributed toward the
bottom edge of the wireless device 400.
[0054] Furthermore, the individual power amplifiers in the packaged
power amplifier dies 410A, 410B can be rotated, as illustrated in
FIG. 5D. For example, an output of a first power amplifier in the
power amplifier die 410A can face the right edge of the wireless
device 400 (e.g., the output of the first power amplifier in the
power amplifier die 410A is oriented at an angle of 0 degrees on
the x-y axis) and an output of a second power amplifier in the
power amplifier die 410A can face the bottom edge of the wireless
device 400 (e.g., the output of the second power amplifier in the
power amplifier die 410A is oriented at an angle of 270 degrees on
the x-y axis). Thus, a portion of the emissions 412A (e.g., 412A-1)
can be distributed toward the right edge of the wireless device 400
and a portion of the emissions 412A (e.g., 412A-2) can be
distributed toward the bottom edge of the wireless device 400.
Likewise, an output of a first power amplifier in the power
amplifier die 410B can face the top edge of the wireless device 400
(e.g., the output of the first power amplifier in the power
amplifier die 410B is oriented at an angle of 90 degrees on the x-y
axis) and an output of a second power amplifier in the power
amplifier die 410B can face the bottom-left edge of the wireless
device 400 (e.g., the output of the second power amplifier in the
power amplifier die 410B is oriented at an angle of 230 degrees on
the x-y axis). Thus, a portion of the emissions 412B (e.g., 412B-1)
can be distributed toward the top edge of the wireless device 400
and a portion of the emissions 412B (e.g., 412B-2) can be
distributed toward the bottom-left edge of the wireless device 400
at an angle of 230 degrees.
[0055] In some embodiments, the angle at which the power amplifiers
410A-N are rotated is determined by a computing system (e.g., a
desktop, laptop, tablet, mobile phone, etc.) that includes
computer-readable memory, where the computer-readable memory stores
instructions that, when executed, cause the computing system to
execute an application that simulates the emissions radiated by the
power amplifiers 410A-N of the wireless device 400. For example,
the application can include executable program code that directs
the computing system to determine an orientation of one or more
power amplifiers and/or antennas to meet FCC regulatory limits. As
described herein, the power amplifiers 410A-N may not all radiate
the same level of harmonics and in fact the level of harmonics
radiated by a power amplifier 410A-N may be dependent on the
matching network at the output of the respective power amplifier
410A-N. Thus, the application may identify the level of harmonics
radiated by an individual power amplifier 410A-N and use this
information to determine the direction that an individual power
amplifier 410A-N could be rotated to distribute the emissions in
different directions (e.g., toward the top edge of the wireless
device 400, toward the bottom edge of the wireless device 400,
toward the left edge of the wireless device 400, toward the right
edge of the wireless device 400, toward the bottom-left corner of
the wireless device 400, toward the bottom-right corner of the
wireless device 400, toward the top-left corner of the wireless
device 400, toward the top-right corner of the wireless device 400,
etc.) that would result in the wireless device 400 meeting FCC
regulatory limits.
[0056] In further embodiments, the application takes into account
additional information to determine the angle of rotation of the
power amplifiers 410A-N as placed on the PCB of the wireless device
400. For example, the application may use a representation of a
schematic diagram of the components of the wireless device 400 to
identify the relative location of the power amplifiers 410A-N with
respect to the other components of the wireless device 400. The
application may then suggest rotating the power amplifiers 410A-N
in a way that also minimizes bondwires or other connections between
the power amplifiers 410A-N and the other components of the
wireless device 400, that prevents the overlap of connections
between the power amplifiers 410A-N and the other components of the
wireless device 400, that reduce interference between the different
components of the wireless device 400, and/or that causes the PCB
layout to meet some or all of the design requirements of the
wireless device 400.
[0057] In other embodiments, the angle at which the power
amplifiers 410A-N are rotated is determined manually by testing an
operational wireless device 400. For example, the power amplifiers
410A-N may initially be soldered onto a PCB along with other
components of the wireless device 400. The wireless device 400 can
be turned on and the amount of emissions generated in various
directions around the wireless device 400 (e.g., in a spherical
area surrounding the wireless device 400) can be measured using a
measurement tool or probe. If the amount of emissions in a given
direction exceed FCC regulatory limits, emissions radiated by one
or more of the power amplifiers 410A-N can be measured (e.g., by
placing the measurement tool or probe above the respective power
amplifier 410A-N) to determine which power amplifiers 410A-N are
contributing to the emissions radiated in the direction that exceed
FCC regulatory limits. Once such power amplifiers 410A-N are
identified, one or more of the power amplifiers 410A-N can be
rotated such that an output of the power amplifier 410A-N faces a
direction in which the radiated emissions do not exceed the FCC
regulatory limits (and still will not exceed the FCC regulatory
limits if the rotation is made). The one or more power amplifiers
410A-N can be rotated by, for example, de-soldering the respective
power amplifier 410A-N and re-soldering the respective power
amplifier 410A-N in the new rotated orientation. After rotation,
the emissions radiated by the power amplifiers 410A-N when the
wireless device 400 is operating can be measured again and the
above-process can be repeated until the emissions radiated in any
given direction fall below the FCC regulatory limits.
Alternatively, the wireless device 400 may be a test device and
future wireless devices 400 can be designed with the identified
rotations.
[0058] In some embodiments, each power amplifier 410A-N has an
output that faces a different direction, such as illustrated in
FIG. 5A. In other embodiments, two or more power amplifiers 410A-N
have outputs that face the same direction and other power
amplifiers 410A-N have outputs that face another direction, such as
illustrated in FIG. 5B.
[0059] In addition to orienting the power amplifiers 410A-N such
that the emissions 412A-N radiated by the power amplifiers 410A-N
are distributed in different directions around the wireless device
400, one or more of the power amplifiers 410A-N may be shielded
using an RF shield and/or one or more of the power amplifiers
410A-N may be coupled to or be in proximity to an RF absorber. The
RF shield and/or the RF absorber may be smaller than would
otherwise be expected if the power amplifiers 410A-N are not
rotated as described herein, however, because of the benefits
provided by changing the orientation of the power amplifiers
410A-N. Thus, the emissions 412A-N generated by the power
amplifiers 410A-N may be reduced in addition to being distributed
in different directions.
[0060] In further embodiments, the antennas 405A-N can be
physically rotated to distribute harmonics radiated by the antennas
405A-N in different directions, as illustrated in FIG. 5E. As
described herein, while the power amplifiers 410A-N themselves
produce and radiate emissions 412A-N, the antennas 405A-N may also
radiate emissions (e.g., by receiving harmonics generated by the
power amplifiers 410A-N via the transmission lines that couple the
power amplifiers 410A-N to the antennas 405A-N). In implementations
of the wireless device 400 in which the antennas 405A-N are
isotropic (e.g., transmit signals in some or all directions), the
actual orientation of the antennas 405A-N may not be important
given that the antennas 405A-N are transmitting in all directions
anyway. Thus, the antennas 405A-N can be rotated in a manner as
described above with respect to the power amplifiers 410A-N to
distribute the emissions radiated by the antennas 405A-N in
different directions across the wireless device 400. For example,
the antenna 405A can be oriented such that the output of the
antenna 405A (e.g., the opposite side from which the transmission
line from the power amplifier 410A couples to the antenna 405A)
faces the bottom edge of the wireless device 400 (e.g., the output
of the antenna 405A is oriented at an angle of 270 degrees on the
x-y axis, as indicated by the arrow in the antenna 405A). The
antenna 405B can be oriented such that the output of the antenna
405B faces a direction that is at an angle 15 degrees from an axis
that runs parallel to the left and right edge of the wireless
device 400 (e.g., the output of the antenna 405B is oriented at an
angle of 255 degrees on the x-y axis, as indicated by the arrow in
the antenna 405B). The antenna 405C can be oriented such that the
output of the antenna 405C faces a direction that is at an angle 45
degrees from an axis that runs parallel to the left and right edge
of the wireless device 400 (e.g., the output of the antenna 405C is
oriented at an angle of 315 degrees on the x-y axis, as indicated
by the arrow in the antenna 405C). The antenna 405N can be oriented
such that the output of the antenna 405N faces a direction that is
parallel with an axis that runs parallel to the top and bottom edge
of the wireless device 400 (e.g., the output of the antenna 405N is
oriented at an angle of 0 degrees on the x-y axis, as indicated by
the arrow in the antenna 405N).
[0061] The antennas 405A-N can be rotated at any angle such that
the outputs of the antennas 405A-N face any direction. The
application described above can simulate the emissions 412A-N
radiated by the power amplifiers 410A-N and the emissions radiated
by the antennas 405A-N to determine the optimal orientation of the
power amplifiers 410A-N and/or the antennas 405A-N on the PCB of
the wireless device 400. Alternatively, the emissions 412A-N
radiated by the antennas 405A-N can be measured using the
measurement tool or probe and such information can be taken into
account when determining which power amplifiers 410A-N and/or
antennas 405A-N to rotate.
Example Flowchart for Determining the Orientation of Power
Amplifiers
[0062] FIG. 6 illustrates an example flowchart of a process 600 for
determining the physical orientation of power amplifiers laid out
on the PCB of a wireless device, such as the wireless device 11 of
FIG. 2 and/or the wireless device 400 of FIGS. 4-5E. The process
600 may be performed by a computing system (e.g., a desktop,
laptop, tablet, mobile phone, etc.) that includes computer-readable
memory, where the computer-readable memory stores instructions
that, when executed, cause the computing system to execute an
application (e.g., a circuit simulator) that performs the process
600. The process 600 can be implemented, in part or entirely, by a
hardware-only application-specific processor of the computing
system that executes the instructions. The process 600 may include
fewer or additional steps than are illustrated in FIG. 6.
Furthermore, the process 600 may perform the steps illustrated in
FIG. 6 in any order.
[0063] At block 602, an amount of emissions radiated by a first
power amplifier is determined. For example, the computing system
may use a schematic diagram and/or a PCB layout of a wireless
device to identify components that may affect the amount of
emissions radiated by the first power amplifier to simulate the
amount of radiated emissions. Such structures may include the
matching structures inside the first power amplifier (e.g., a
transistor at the output of the first power amplifier), the
matching network at the output of the first power amplifier,
bondwires or transmission lines that couple the first power
amplifier to the matching network at the output of the first power
amplifier, and/or the like.
[0064] At block 604, an amount of emissions radiated by a second
power amplifier is determined. The first and second power
amplifiers may be included in the same wireless device. Each power
amplifier may be used to transmit signals using a different
antenna. The amount of emissions radiated by the second power
amplifier may be determined in a same manner as described above
with respect to the first power amplifier. In further embodiments,
the computing system determines an amount of emissions radiated by
the antenna coupled to the first power amplifier and an amount of
emissions radiated by the antenna coupled to the second power
amplifier.
[0065] At block 606, an adjusted orientation of the second power
amplifier is determined such that the amount of emissions radiated
by the first power amplifier and the amount of emissions radiated
by the second power amplifier are distributed in different
directions. For example, the first power amplifier may be oriented
such that an output of the first power amplifier is parallel with
an axis that runs along a bottom and top edge of the PCB when
looking at the PCB from a top-down view (such as illustrated in
FIGS. 5A-5E). The computing system may use the determined amount of
emissions radiated by the first and second power amplifiers to
determine an orientation of the second power amplifier such that
the net emissions measured over any portion of the PCB (when both
power amplifiers are operating) is less than FCC regulatory limits.
In some cases, such an orientation may be having the output of the
second power amplifier face the bottom edge of the PCB such that
the output of the second power amplifier is parallel with an axis
that runs along a left and right edge of the PCB when looking at
the PCB from a top-down view. The output of the second power
amplifier can be oriented at any angle (e.g., from about 0 degrees
to about 360 degrees) relative to the orientation of the output of
the first power amplifier. In further embodiments, the antenna
coupled to the first power amplifier and/or the antenna coupled to
the second power amplifier can be rotated in different directions
to reduce the net emissions measured in any one direction.
[0066] At block 608, the orientation of the second power amplifier
is adjusted to the adjusted orientation. For example, the computing
system can orient the second power amplifier in the adjusted
orientation to determine whether FCC regulatory limits are met.
[0067] At block 610, whether net emissions in a first direction are
below a threshold value is determined. For example, the threshold
value can be the FCC regulatory limits. Once the orientation of the
second power amplifier is adjusted to the adjusted orientation, the
computing system may again simulate the amount of emissions
radiated by the first power amplifier and the second power
amplifier. If the net emissions radiated by the first power
amplifier and the second power amplifier in a first direction are
below the FCC regulatory limits, then the computing system can
write a file that can be used (e.g., by a soldering machine) to
orient the first and second power amplifiers on a PCB, can generate
a report that identifies the orientations of the first and second
power amplifiers that results in meeting FCC regulatory limits
(e.g., a report with instructions that can be followed manually to
solder the power amplifiers to a PCB), and/or the like. If the net
emissions radiated by the first power amplifier and the second
power amplifier in the first direction are above the FCC regulatory
limits, the process 600 can repeat any of blocks 602 through 610
until the net emissions in the first direction are below the FCC
regulatory limits. The process 600 can also be repeated until the
net emissions in all directions are below the FCC regulatory
limits.
[0068] FIG. 7 illustrates another example flowchart of a process
700 for determining the physical orientation of power amplifiers
laid out on the PCB of a wireless device, such as the wireless
device 11 of FIG. 2 and/or the wireless device 400 of FIGS. 4-5E.
The process 700 may be performed manually. The process 700 may
include fewer or additional steps than are illustrated in FIG. 7.
Furthermore, the process 700 may perform the steps illustrated in
FIG. 7 in any order.
[0069] At block 702, an amount of emissions radiated by a first
power amplifier is determined. For example, the first power
amplifier can be soldered to the PCB of a wireless device that is
operational. The amount of emissions radiated by the first power
amplifier can be measured by a measurement tool or probe while the
wireless device is operating.
[0070] At block 704, an amount of emissions radiated by a second
power amplifier is determined. The first and second power
amplifiers may be included on the same PCB of the wireless device.
Each power amplifier may be used to transmit signals using a
different antenna. The amount of emissions radiated by the second
power amplifier may be determined in a same manner as described
above with respect to the first power amplifier. In further
embodiments, an amount of emissions radiated by the antenna coupled
to the first power amplifier and an amount of emissions radiated by
the antenna coupled to the second power amplifier are also measured
using the measurement tool or probe.
[0071] At block 706, whether the net emissions radiated in a first
direction are below a threshold value is determined. For example,
the threshold value can be the FCC regulatory limits.
[0072] At block 708, in response to a determination that the net
emissions radiated in the first direction are above the threshold
value, an adjusted orientation of the second power amplifier is
determined. For example, a determination can be made of a second
direction in which the net emissions are less than the threshold
value to a degree such that the addition of emissions radiated by
the second power amplifier still would result in the net emissions
radiated in the second direction being less than the threshold
value. The adjusted orientation can be an orientation of the second
power amplifier that results in the emissions radiated by the
second power amplifier being radiated in the second direction.
[0073] At block 710, the orientation of the second power amplifier
is adjusted to the adjusted orientation. For example, the second
power amplifier can be de-soldered from the PCB and re-soldered to
the PCB to adjust the orientation to the adjusted orientation.
[0074] At block 712, whether net emissions in the first direction
are below the threshold value is determined. For example, once the
orientation of the second power amplifier is adjusted to the
adjusted orientation, the amount of emissions radiated in the first
direction can be measured again. If the net emissions radiated in
the first direction are below the FCC regulatory limits, then the
process 700 is complete. Otherwise, the process 700 can repeat any
of blocks 702 through 712 until the net emissions in the first
direction are below the FCC regulatory limits. The process 700 can
also be repeated until the net emissions in all directions are
below the FCC regulatory limits.
Applications
[0075] Some of the embodiments described above have provided
examples in connection with wireless devices or mobile phones.
However, the principles and advantages of the embodiments can be
used for any other systems or apparatus that have needs for
multiple power amplifiers.
[0076] Such varied orientations of power amplifiers can be
implemented in various electronic devices. Examples of the
electronic devices can include, but are not limited to, consumer
electronic products, parts of the consumer electronic products,
electronic test equipment, etc. Examples of the electronic devices
can also include, but are not limited to, memory chips, memory
modules, circuits of optical networks or other communication
networks, and disk driver circuits. The consumer electronic
products can include, but are not limited to, a mobile phone, a
telephone, a television, a computer monitor, a computer, a
hand-held computer, a personal digital assistant (PDA), a
microwave, a refrigerator, an automobile, a stereo system, a
cassette recorder or player, a DVD player, a CD player, a VCR, an
MP3 player, a radio, a camcorder, a camera, a digital camera, a
portable memory chip, a washer, a dryer, a washer/dryer, a copier,
a facsimile machine, a scanner, a multi-functional peripheral
device, a wrist watch, a clock, etc. Further, the electronic
devices can include unfinished products.
CONCLUSION
[0077] Unless the context clearly requires otherwise, throughout
the description and the claims, the words "comprise," "comprising,"
and the like are to be construed in an inclusive sense, as opposed
to an exclusive or exhaustive sense; that is to say, in the sense
of "including, but not limited to." The word "coupled", as
generally used herein, refers to two or more elements that may be
either directly connected, or connected by way of one or more
intermediate elements. Likewise, the word "connected", as generally
used herein, refers to two or more elements that may be either
directly connected, or connected by way of one or more intermediate
elements. Additionally, the words "herein," "above," "below," and
words of similar import, when used in this application, shall refer
to this application as a whole and not to any particular portions
of this application. Where the context permits, words in the above
Detailed Description using the singular or plural number may also
include the plural or singular number respectively. The word "or"
in reference to a list of two or more items, that word covers all
of the following interpretations of the word: any of the items in
the list, all of the items in the list, and any combination of the
items in the list.
[0078] Moreover, conditional language used herein, such as, among
others, "can," "could," "might," "can," "e.g.," "for example,"
"such as" and the like, unless specifically stated otherwise, or
otherwise understood within the context as used, is generally
intended to convey that certain embodiments include, while other
embodiments do not include, certain features, elements and/or
states. Thus, such conditional language is not generally intended
to imply that features, elements and/or states are in any way
required for one or more embodiments or that one or more
embodiments necessarily include logic for deciding, with or without
author input or prompting, whether these features, elements and/or
states are included or are to be performed in any particular
embodiment.
[0079] The above detailed description of embodiments of the
invention is not intended to be exhaustive or to limit the
invention to the precise form disclosed above. While specific
embodiments of, and examples for, the invention are described above
for illustrative purposes, various equivalent modifications are
possible within the scope of the invention, as those skilled in the
relevant art will recognize. For example, while processes or blocks
are presented in a given order, alternative embodiments may perform
routines having steps, or employ systems having blocks, in a
different order, and some processes or blocks may be deleted,
moved, added, subdivided, combined, and/or modified. Each of these
processes or blocks may be implemented in a variety of different
ways. Also, while processes or blocks are at times shown as being
performed in series, these processes or blocks may instead be
performed in parallel, or may be performed at different times.
[0080] The teachings of the invention provided herein can be
applied to other systems, not necessarily the system described
above. The elements and acts of the various embodiments described
above can be combined to provide further embodiments.
[0081] While certain embodiments of the inventions have been
described, these embodiments have been presented by way of example
only, and are not intended to limit the scope of the disclosure.
Indeed, the novel methods and systems described herein may be
embodied in a variety of other forms; furthermore, various
omissions, substitutions and changes in the form of the methods and
systems described herein may be made without departing from the
spirit of the disclosure. The accompanying claims and their
equivalents are intended to cover such forms or modifications as
would fall within the scope and spirit of the disclosure.
* * * * *