U.S. patent application number 16/792726 was filed with the patent office on 2021-01-07 for low-cost method for selectively reducing switch loss.
The applicant listed for this patent is MOTOROLA MOBILITY LLC. Invention is credited to BRIAN H. BREMER, ARMIN KLOMSDORF, JOHN R. MURA.
Application Number | 20210006271 16/792726 |
Document ID | / |
Family ID | |
Filed Date | 2021-01-07 |
United States Patent
Application |
20210006271 |
Kind Code |
A1 |
BREMER; BRIAN H. ; et
al. |
January 7, 2021 |
LOW-COST METHOD FOR SELECTIVELY REDUCING SWITCH LOSS
Abstract
A method includes identifying a first output terminal of a radio
frequency front end (RFFE) switch including a single pole input
terminal and a number (N) of output terminals, the first output
terminal selectively connected to a single RF band path. Each of
the N output terminals is a component of a respective one of N
throws of the RFFE switch, with N being greater than one. The N
output terminals include the first output terminal corresponding to
a first throw of the N throws and at least one additional output
terminal not connected to any radio frequency (RF) band path. The
at least one additional output terminal includes a second output
terminal corresponding to a second throw of the N throws. The
method includes forming a parallel connection between the single
pole input terminal and the single RF band path. The parallel
connection provides at least two parallel branches for routing RF
signals being transceived between the single pole input terminal
and the single RF band path.
Inventors: |
BREMER; BRIAN H.; (ARLINGTON
HEIGHTS, IL) ; MURA; JOHN R.; (CLARENDON HILLS,
IL) ; KLOMSDORF; ARMIN; (CHICAGO, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MOTOROLA MOBILITY LLC |
CHICAGO |
IL |
US |
|
|
Appl. No.: |
16/792726 |
Filed: |
February 17, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16460375 |
Jul 2, 2019 |
10601451 |
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16792726 |
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Current U.S.
Class: |
1/1 |
International
Class: |
H04B 1/00 20060101
H04B001/00; H05K 1/02 20060101 H05K001/02 |
Claims
1. A method comprising: identifying a first output terminal of a
single input radio frequency front end (RFFE) switch that includes
a single pole input terminal and multiple output terminals, each of
the multiple output terminals being corresponding to a respective
one of multiple throws of the RFFE switch, the multiple output
terminals comprising the first output terminal corresponding to a
first throw of the multiple throws and at least one additional
output terminal not connected to any radio frequency (RF) band
path; and forming a parallel connection between the single pole
input terminal and a single RF band path, the parallel connection
providing at least two branches for routing RF signals being
transceived between the single pole input terminal and the single
RF band path.
2. The method of claim 1, wherein the RFEE switch is a single-pole
N-throw switch and forming the parallel connection comprises:
placing a jumper that connects the first output terminal to at
least a second output terminal from among the at least one
additional output terminal, the second output terminal
corresponding to a second throw of the multiple throws; and closing
the first throw and the second throw.
3. The method of claim 2, wherein: the at least one additional
output terminal comprises multiple additional output terminals and
the jumper connects the first output terminal to multiple of the at
least one additional output terminal; and the method further
comprises, for each of the multiple additional output terminals to
which the jumper connects, configuring a corresponding throw to
form a branch of the parallel connection when the corresponding
throw is closed.
4. The method of claim 2, wherein the jumper comprises at least one
of a zero (0) ohm resistor, a series resonant capacitor, or a
parallel resonant inductor.
5. The method of claim 1, wherein: the single pole input terminal
is connected to an antenna to enable transmission and reception of
the RF signals via the antenna.
6. The method of claim 1, wherein: the multiple output terminals of
the RFFE switch further comprise a third output terminal
corresponding to a third throw of the multiple throws and
selectively connected to a second single RF band path; the at least
one additional output terminal includes a fourth output terminal
corresponding to a fourth throw of the multiple throws; and the
method further comprises forming a parallel connection between the
single pole input terminal and the second single RF band path, the
parallel connection providing at least two parallel branches for
routing RF signals being transceived between the single pole input
terminal and the second single RF band path.
7. A radio frequency front end (RFFE) switch comprising: a single
pole input terminal; multiple output terminals, each output
terminal being connectable to the single pole input terminal via a
respective one of multiple throws of the RFFE switch, the multiple
output terminals comprising: a first output terminal corresponding
to a first throw that is selectively connected to a single RF band
path; and at least one additional output terminal not connected to
an RF band path, each of the at least one additional output
terminal corresponding to a respective throw; and a parallel
connection formed between the single pole input terminal and the
single RF band path, the parallel connection providing at least two
parallel branches for routing RF signals being transceived between
the single pole input terminal and the single RF band path.
8. The RFFE switch of claim 7, wherein the parallel connection
comprises: a closed configuration of the first throw and a second
throw corresponding to a second output terminal of the at least one
additional output terminals; and a jumper that connects the first
output terminal to at least the second output terminal.
9. The RFFE switch of claim 8, wherein: the at least one additional
output terminal comprises multiple additional output terminals; the
jumper connects the first output terminal to multiple terminals
from among the at least one additional output terminal; and each of
the multiple additional output terminals are a component of a
respective throw that closes to form a branch of the parallel
connection.
10. The RFFE switch of claim 8, wherein the jumper comprises at
least one of a zero (0) ohm resistor, a series resonant capacitor,
or a parallel resonant inductor.
11. The RFFE switch of claim 7, wherein the single pole input
terminal is connected to an antenna to enable transmission and
reception of the RF signals via the antenna.
12. The RFFE switch of claim 7, wherein: the multiple output
terminals further comprise a third output terminal corresponding to
a third throw that connects to a second single RF band path; the at
least one additional output terminals includes a fourth output
terminal corresponding to a fourth throw of the multiple throws;
and a parallel connection is formed between the single pole input
terminal and the second single RF band path, the parallel
connection providing at least two parallel branches for routing RF
signals being transceived between the single pole input terminal
and the second single RF band path.
13. A communication device comprising: a radio frequency front end
(RFFE) switch comprising: a single pole input terminal; multiple
output terminals, each output terminal being connectable to the
single pole input terminal via a respective one of multiple throws
of the RFFE switch, the multiple output terminals comprising: a
first output terminal corresponding to a first throw that is
selectively connected to a single RF band path on a printed circuit
board (PCB); and at least one additional output terminal not
connected to an RF band path on the PCB, each of the at least one
additional output terminal corresponding to a respective throw; and
a parallel connection formed between the single pole input terminal
and the single RF band path, the parallel connection providing at
least two parallel branches for routing RF signals being
transceived between the single pole input terminal and the single
RF band path.
14. The communication device of claim 13, wherein the parallel
connection comprises: a closed configuration of the first throw and
a second throw corresponding to a second output terminal of the at
least one additional output terminals; and a jumper that connects
the first output terminal to at least the second output
terminal.
15. The communication device of claim 14, wherein: the at least one
additional output terminal comprises multiple additional output
terminals; the jumper connects the first output terminal to
multiple output terminals from among the at least one additional
output terminal; and each of the multiple additional output
terminals are a component of a respective throw that is closed to
form a branch of the parallel connection.
16. The communication device of claim 14, wherein the jumper
comprises at least one of a zero (0) ohm resistor, a series
resonant capacitor, or a parallel resonant inductor.
17. The communication device of claim 13, wherein the single pole
input terminal of the RFFE switch is configured to connect to an
antenna for transmission or reception of the RF signals via the
antenna.
18. The communication device of claim 13, wherein, within the RFFE
switch: the multiple output terminals further comprise a third
output terminal corresponding to a third throw that connects to a
second single RF band path; the at least one additional output
terminals includes a fourth output terminal corresponding to a
fourth throw of the multiple throws; and a parallel connection is
formed between the single pole input terminal and the second single
RF band path, the parallel connection providing at least two
parallel branches for routing RF signals being transceived between
the single pole input terminal and the second single RF band path.
Description
RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 16/460,375, filed Jul. 2, 2019, the content of
which is incorporated herein by reference.
BACKGROUND
1. Technical Field
[0002] The present disclosure generally relates to electronic
device architecture for radio frequency communications, and more
particularly to low-cost methods for selectively reducing switch
loss within electronic devices engaged in radio frequency
communications.
2. Description of the Related Art
[0003] Mobile communication devices are typically equipped with a
printed circuit board (PCB) that includes a radio frequency front
end (RFFE) that transmits and receives radio frequency (RF) signals
via one or more antenna(s). Different geographical regions require
wireless communication systems to use different RF bands for
cellular communication. For example, North America uses a subset of
RF bands that is different from the subset of RF bands used in
South America, and different from the subset of RF bands used in
Asia. A smartphone manufacturer will often release different
variants of a single product (e.g., smartphone) so that each
variant is configured to support a different subset of RF bands
based on the different geographical regions of the world where the
product is sold to an end user (assuming regional use). The term
"SKU" is commonly used to refer to a variant of a single product,
and means a given configuration of a product that ships to a
certain region.
[0004] Current smartphone design practices entail designing a
single-product PCB that is used worldwide, in every geographical
region in which the smartphone operates. That is, all variants of
the single product have the same identical PCB. The single-product
PCB includes, within the RFFE, an antenna switch that can
accommodate the full number of bands supported across all SKUs.
Components not required in a given SKU will not be populated, which
leaves unused switch throws. An unused switch throw is an example
of excess hardware.
[0005] Year after year, the number of RF bands required in
smartphones continues to increase. In order to accommodate the
multitude of RF bands required in smartphones, the RFFE includes a
high throw-count switch that is placed near the antenna. The
insertion loss of this high throw-count switch has a positive
correlation with the number of RF bands supported by the
single-product PCB. This high throw-count switch is used as the
antenna switch of the single-product PCB.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The description of the illustrative embodiments is to be
read in conjunction with the accompanying drawings. It will be
appreciated that for simplicity and clarity of illustration,
elements illustrated in the figures have not necessarily been drawn
to scale. For example, the dimensions of some of the elements are
exaggerated relative to other elements. Embodiments incorporating
teachings of the present disclosure are shown and described with
respect to the figures presented herein, in which:
[0007] FIG. 1 is a block diagram representation of an example
mobile device within which certain aspects of the disclosure can be
practiced, in accordance with one or more embodiments of this
disclosure;
[0008] FIG. 2 illustrates a single product printed circuit board
(PCB) that is populated with components required for worldwide
geographical regions and that includes a full-band antenna switch,
in accordance with one or more embodiments of this disclosure;
[0009] FIGS. 3A and 3B illustrate two examples of the
single-product PCB of FIG. 2 that is configured to include only
components required to support RF bands for a particular
geographical region and that has been modified according to the
low-cost methods for selectively reducing switch loss, in
accordance with one or more embodiments of this disclosure; and
[0010] FIG. 4 is a flow chart illustrating low-cost methods for
configuring an antenna switch and selectively reducing switch loss,
in accordance with one or more embodiments.
DETAILED DESCRIPTION
[0011] Disclosed are a radio frequency front end (RFFE) switch
configured for selectively reducing switch loss, a communication
device with the configured RFFE switch, and a method for
configuring the RFFE switch. The method includes providing the RFFE
switch including a single pole input terminal and a number (N) of
output terminals. Each of the N output terminals is a component of
a respective one of N throws of the RFFE switch, with N being
greater than one. The N output terminals include a first output
terminal corresponding to a first throw of the N throws and at
least one additional output terminal not connected to any radio
frequency (RF) band path. The at least one additional output
terminal includes a second output terminal corresponding to a
second throw of the N throws. The method includes connecting the
first output terminal to a single RF band path. The method includes
forming a parallel connection between the single pole input
terminal and the single RF band path. The parallel connection
provides at least two parallel branches for routing RF signals
being transceived between the single pole input terminal and the
single RF band path. According to one aspect of the method, forming
the parallel connection includes, placing a jumper that connects
the first output terminal to at least the second output terminal,
and closing the first throw and the second throw.
[0012] According to another embodiment, an RFFE switch includes a
single pole input terminal. The RFFE switch includes a number (N)
of output terminals. Each of the N output terminals is a component
of a respective one of N throws of the RFFE switch, where N is
greater than one. The N output terminals include a first output
terminal corresponding to a first throw of the N throws that
connects to a single radio frequency (RF) band path, and at least
one additional output terminal not connected to any RF band path.
The at least one additional output terminal includes a second
output terminal corresponding to a second throw of the N throws.
The RFFE switch includes a parallel connection formed between the
single pole input terminal and the single RF band path. The
parallel connection provides at least two parallel branches for
routing RF signals being transceived between the single pole input
terminal and the single RF band path.
[0013] According to another embodiment, a communication device
includes a printed circuit board (PCB) including a number (N) of
radio frequency (RF) signal paths for transmitting and receiving RF
signals within respective single RF bands. The communication device
includes a radio frequency front end (RFFE) switch positioned on
and connected to the PCB. The RFFE switch includes a single pole
input terminal. The RFFE switch includes a number (N) of output
terminals. Each of the N output terminals is a component of a
respective one of N throws of the RFFE switch, wherein N is greater
than one. The N output terminals include a first output terminal
corresponding to a first throw of the N throws that connects to a
single radio frequency (RF) band path, and at least one additional
output terminal not connected to any RF band path. The at least one
additional output terminal includes a second output terminal
corresponding to a second throw of the N throws. The RFFE switch
includes a parallel connection formed between the single pole input
terminal and the single RF band path. The parallel connection
provides at least two parallel branches for routing RF signals
being transceived between the single pole input terminal and the
single RF band path.
[0014] As a technical advantage, by utilizing a throw(s) of the
RFFE switch that corresponds to a depopulated RF band path(s),
embodiments of the present disclosure overcome a problem of
increased insertion loss resulting from increased quantity of RF
bands supported by the single-product PCB, and the embodiments both
reduce insertion loss and repurpose excess hardware.
[0015] In the following description, specific example embodiments
in which the disclosure may be practiced are described in
sufficient detail to enable those skilled in the art to practice
the disclosed embodiments. For example, specific details such as
specific method sequences, structures, elements, and connections
have been presented herein. However, it is to be understood that
the specific details presented need not be utilized to practice
embodiments of the present disclosure. It is also to be understood
that other embodiments may be utilized and that logical,
architectural, programmatic, mechanical, electrical and other
changes may be made without departing from general scope of the
disclosure. The following detailed description is, therefore, not
to be taken in a limiting sense, and the scope of the present
disclosure is defined by the appended claims and equivalents
thereof.
[0016] References within the specification to "one embodiment," "an
embodiment," "embodiments", or "alternate embodiments" are intended
to indicate that a particular feature, structure, or characteristic
described in connection with the embodiment is included in at least
one embodiment of the present disclosure. The appearance of such
phrases in various places within the specification are not
necessarily all referring to the same embodiment, nor are separate
or alternative embodiments mutually exclusive of other embodiments.
Further, various features are described which may be exhibited by
some embodiments and not by others. Similarly, various aspects are
described which may be aspects for some embodiments but not other
embodiments.
[0017] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the disclosure. As used herein, the singular forms "a", "an", and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof.
Moreover, the use of the terms first, second, etc. do not denote
any order or importance, but rather the terms first, second, etc.
are used to distinguish one element from another.
[0018] It is understood that the use of specific component, device
and/or parameter names and/or corresponding acronyms thereof, such
as those of the executing utility, logic, and/or firmware described
herein, are for example only and not meant to imply any limitations
on the described embodiments. The embodiments may thus be described
with different nomenclature and/or terminology utilized to describe
the components, devices, parameters, methods and/or functions
herein, without limitation. References to any specific protocol or
proprietary name in describing one or more elements, features or
concepts of the embodiments are provided solely as examples of one
implementation, and such references do not limit the extension of
the claimed embodiments to embodiments in which different element,
feature, protocol, or concept names are utilized. Thus, each term
utilized herein is to be provided its broadest interpretation given
the context in which that term is utilized.
[0019] Those of ordinary skill in the art will appreciate that the
hardware components and basic configuration depicted in the
following figures may vary. For example, the illustrative
components within the presented devices are not intended to be
exhaustive, but rather are representative to highlight components
that can be utilized to implement the present disclosure. For
example, other devices/components may be used in addition to, or in
place of, the hardware depicted. The depicted example is not meant
to imply architectural or other limitations with respect to the
presently described embodiments and/or the general disclosure.
[0020] Within the descriptions of the different views of the
figures, the use of the same reference numerals and/or symbols in
different drawings indicates similar or identical items, and
similar elements can be provided similar names and reference
numerals throughout the figure(s). The specific identifiers/names
and reference numerals assigned to the elements are provided solely
to aid in the description and are not meant to imply any
limitations (structural or functional or otherwise) on the
described embodiments.
[0021] FIG. 1 illustrates a block diagram representation of a
mobile device 100, within which one or more of the described
features of the various embodiments of the disclosure can be
implemented. Mobile device 100 may be a handheld device a notebook
computer, a mobile phone, a digital camera, a tablet computer, or
any other suitable device, and may vary in size, shape,
performance, functionality, and price.
[0022] Example mobile device 100 includes at least one processor
integrated circuit (IC), processor IC 105. Included within
processor IC 205 are data processor 107 and digital signal
processor (DSP) 109. Processor IC 205 is coupled to system memory
110 and non-volatile storage 220 via an intersystem communication
fabric, such as system interconnect 115. System interconnect 115
can be interchangeably referred to as a system bus, in one or more
embodiments. Also coupled to system interconnect 115 is storage 120
within which can be stored one or more software and/or firmware
modules and/or data (not specifically shown).
[0023] As shown, system memory 110 can include therein a plurality
of software and/or firmware modules including application(s) 112,
operating system (O/S) 114, basic input/output system/unified
extensible firmware interface (BIOS/UEFI) 116, and other firmware
(F/W) 118. System memory 120 may be a combination of volatile and
non-volatile memory, such as random access memory (RAM) and
read-only memory (ROM). That is, system memory 110 can store
program code or similar data associated with applications 112, O/S
114, BIOS/UEFI 116, and firmware 118. The software and/or firmware
modules provide varying functionality when their corresponding
program code is executed by processor IC 205 or by secondary
processing devices within mobile device 100.
[0024] In some embodiments, storage 120 can be a hard drive or a
solid-state drive. The one or more software and/or firmware modules
within storage 120 can be loaded into system memory 110 during
operation of DPS 100. The various software and/or firmware modules
have varying functionality when their corresponding program code is
executed by processor IC 105 or other processing devices within DPS
100.
[0025] Processor IC 105 supports connection by, and processing of
signals from, one or more connected input devices such as
microphone 142, touch sensor 144, camera 145, and keypad 146.
Processor IC 105 also supports connection by and processing of
signals to one or more connected output devices, such as speaker
152 and display 154. Additionally, in one or more embodiments, one
or more device interfaces 160, such as an optical reader, a
universal serial bus (USB), a card reader, Personal Computer Memory
Card International Association (PCMIA) slot, and/or a
high-definition multimedia interface (HDMI), can be associated with
mobile device 100. In at least one embodiment, device interfaces
160 can be utilized to enable data to be read from or stored to
additional devices (not shown) for example a compact disk (CD),
digital video disk (DVD), flash drive, or flash memory card. These
devices can collectively be referred to as removable storage
devices, and are examples of non-transitory computer readable
storage media. Mobile device 100 also contains a power source such
as a battery 162 that supplies power to mobile device 100.
[0026] Mobile device 100 further includes Bluetooth transceiver
124, accelerometer 156, global positioning system module (GPS MOD)
158, and gyroscope 157, all of which are communicatively coupled to
processor IC 105. Bluetooth transceiver 124 enables mobile device
100 and/or components within mobile device 100 to communicate
and/or interface with other devices, services, and components that
are located external to mobile device 100. GPS MOD 158 enables
mobile device 100 to communicate and/or interface with other
devices, services, and components to send and/or receive geographic
position information. Gyroscope 157 communicates the angular
position of mobile device 100 using gravity to help determine
orientation. Accelerometer 156 is utilized to measure
non-gravitational acceleration and enables processor IC 105 to
determine velocity and other measurements associated with the
quantified physical movement of a user.
[0027] Mobile device 100 is presented as a wireless communication
device. As a wireless device, mobile device 100 can transmit data
over wireless network 170. Mobile device 100 includes a single
product printed circuit board, PCB 200, that is described more
particularly below with reference to FIG. 2. PCB (200) includes
transceiver 164. Transceiver 164 is communicatively coupled to
processor IC 105 and to antenna 166. Transceiver 164 allows for
wide-area or local wireless communication, via wireless signal 167,
between mobile device 100 and evolved node B (eNodeB) 188, or other
base station, which includes antenna 189. Mobile device 100 is
capable of wide-area or local wireless communication with other
mobile wireless devices or with eNodeB 188 as a part of a wireless
communication network. Mobile device 100 communicates with other
mobile wireless devices by utilizing a communication path involving
transceiver 164, antenna 166, wireless signal 167, antenna 189, and
eNodeB 188. Mobile device 100 additionally includes near field
communication transceiver (NFC TRANS) 168 and wireless power
transfer receiver (WPT RCVR) 169. In one embodiment, other devices
within mobile device 100 utilize antenna 166 to send and/or receive
signals in the form of radio waves. For example, GPS module 158 can
be communicatively couple to antenna 166 to send/and receive
location data.
[0028] By transmitting data over wireless network 170, mobile
device 100 communicates and/or interfaces, via the communication
network, with other devices, services, and components that are
located external (remote) to mobile device 100. These devices,
services, and components can interface with mobile device 100 via
an external network, such as example network 170, using one or more
communication protocols. Network 170 can be a local area network,
wide area network, personal area network, signal communication
network, and the like, and the connection to and/or between network
170 mobile device 100 can be wired or wireless or a combination
thereof. For purposes of discussion, network 170 is indicated as a
single collective component for simplicity. However, it is
appreciated that network 170 can comprise one or more direct
connections to other devices as well as a more complex set of
interconnections as can exist within a wide area network, such as
the Internet.
[0029] In the description of the following figures, reference is
also occasionally made to specific components illustrated within
the preceding figures, utilizing the same reference numbers from
the earlier figures. With reference now to FIG. 2, there is
illustrated example single product PCB 200 that exists within
mobile device 100. Technologies described in this disclosure with
respect to PCB 200 may be applied to various communications
systems, for example, 2G/3G/4G/5G communications systems, and a
next generation communications system, for example, a Global System
for Mobile Communications (GSM) system, a Code Division Multiple
Access (CDMA) system, a Time Division Multiple Access (TDMA)
system, a Wideband Code Division Multiple Access (WCDMA) system, a
Frequency Division Multiple Access (FDMA) system, an Orthogonal
Frequency-Division Multiple Access (OFDMA) system, a single-carrier
FDMA (SC-FDMA) system, a General Packet Radio Service (GPRS)
system, a Long Term Evolution (LTE) system, LTE-Advanced system,
and other communications systems.
[0030] In LTE technology, duplex modes are classified into two
types: Frequency Division Duplex (FDD) and Time Division Duplex
(TDD). In the FDD mode, different frequencies are used in uplink
and downlink channels, and frames of fixed time lengths are used
for both uplink transmission and downlink transmission. In the TDD
mode, uplink transmission and downlink transmission are performed
in different timeslots, and usually share a same frequency.
Compared with FDD, TDD has characteristics of high frequency
utilization and flexible uplink and downlink resource
configuration.
[0031] As shown in FIG. 2, the circuitry of mobile device 100
includes PCB 200 and an antenna 202. Multiple components are
positioned on and connected to PCB 200, including components such
as RFFE 204, transceiver 206, and modem 208. Within example mobile
device 100 (FIG. 1), RFFE 204 is positioned near the antenna 202.
PCB 200 includes a number (N) of single RF signal paths for
transmitting and receiving RF signals within respective
single-carrier RF signal transmission/reception channels.
[0032] Antenna 202 enables modem 208 to transmit one or more RF
signals through a radio channel and to receive one or more RF
signals through a radio channel.
[0033] RFFE 204 connects antenna 202 to a modem 208. RFFE 204
implements radio frequency transmission and reception in the
above-listed types of communications systems, for example, in an
LTE system in a case of inter-band carrier aggregation (CA). In
order for mobile device 100 to perform reception functions, RFFE
204 receives a radio signal from a radio channel, converts the
radio signal into a baseband analog signal, and sends the baseband
analog signal to the baseband processor within modem 208. In order
for mobile device 100 to perform transmission functions, RFFE 204
receives a baseband analog signal from the baseband processor,
converts the baseband analog signal into a radio signal, and
transmits the radio signal to a radio channel. RFFE 204 includes
RFFE switch 210, a power amplifier 214, and band-pass filter
212a-212n. Each band-pass filter 212a-212n is linked to a
respective one of the single RF band paths among the full number
(N) of RF bands that is collectively used in all of the various
geographical regions of the world (i.e., all SKUs).
[0034] RFFE switch 210 is sometimes referred to as a full-band
antenna switch. More particularly, RFFE switch 210 supports the
full number (N) of RF bands that the LTE Protocol has assigned
worldwide. In the embodiment shown in FIG. 2, RFFE switch 210 is
implemented as a single-pole multi-throw switch, commonly referred
to as a single-pole N-throw (SPNT) switch. An SPNT switch includes
a single pole input terminal 216 and N output terminals 218a-218n,
in which each of the N output terminals 218a-218n is a component of
a respective one of N throws 220a-220n of the SPNT switch. The
number N is greater than one, and as a non-limiting example, RFFE
switch 210 shown in FIG. 2 includes six (6) throws 220a-220n (i.e.,
N=6). In at least one other embodiment, RFFE switch 210 is
implemented as multiple SPNT switches. RFFE switch 210 selects
which of the RF bands that antenna 202 uses to transmit or receive
signals.
[0035] Input terminal 216 is connected to antenna 202. Input
terminal 216 enables all of the N throws 220a-220n to be connected
to antenna 202 at the same time.
[0036] Each of the output terminals 218a-218n corresponds to a
throw that connects the input terminal 216 to a corresponding band
path from among the full number (N) of RF band paths (shown in FIG.
2 as Band Path 1 through Band Path n). Each of the full number (N)
of RF band paths includes one of the N output terminals 218a-218n
being connected to a respective one of the N band-pass filters
212a-212n. First output terminal 218a corresponds to a first throw
220a that connects to Band Path 1 of PCB 200. Second output
terminal 218b corresponds to a second throw 220b that connects to
Band Path 2 of PCB 200.
[0037] Each of band-pass filters 212a-212n corresponds to a
specific one of the full number (N) of RF bands paths. According to
one aspect, each output terminal 218a can be associated with one
LTE single-carrier band. For example, first band-pass filter 212a
corresponds to a first LTE single-carrier band, second band-pass
filter 212b corresponds to a second LTE single-carrier band, and
N.sup.th band-pass filter 212n corresponds to an N.sup.th LTE
single-carrier band. First band-pass filter 212a only allows
frequencies that are within the first LTE single-carrier band to
pass through from power amplifier 214 to RFFE switch 210 during
transmission of RF signals. Similarly, first band-pass filter 212a
only allows frequencies that are within the first LTE
single-carrier band to pass through from RFFE switch 210 to
transceiver 206 during reception of RF signals. Analogously, second
band-pass filter 212b only allows frequencies that are within the
second LTE single-carrier band to pass through, and blocks other
frequencies that are outside the second LTE single-carrier
band.
[0038] Power amplifier 214 amplifies low power RF signals outputted
from transceiver 206 to a higher power level that can be
successfully transmitted to (i.e., received by) a base station
(e.g., eNodeB 188 of FIG. 1). Power amplifier 214 supports the full
number (N) of RF bands. That is, power amplifier 214 can receive
low power RF signals from transceiver 206 and output higher power
RF signals to the N band-pass filters 212a-212n.
[0039] Transceiver 206 performs frequency up-conversion of signals
received at antenna 202 and performs frequency down-conversion of
signals to be transmitted from antenna 202.
[0040] Modem 208 includes a baseband processor (not shown), which
processes baseband signals in radio communication. Modem 208
performs modulation and demodulation, enabling mobile device 100 to
transmit and receive data wirelessly via a radio channel.
[0041] Single-product PCB 200 can support various regional SKUs,
each SKU being a configuration that supports communications within
a subset of RF bands associated with a certain geographical region
of the world. For example, the single-product PCB 200 supports a
full number of RF bands that is collectively used in all of the
various geographical regions of the world; However, a first SKU
only uses a first subset of RF bands, while a second SKU only uses
a second subset of RF bands. PCB 200 is designed to include an RFFE
switch 210 that supports whichever geographical region that
requires the most (i.e., highest quantity) of RF bands. PCB 200
includes RFFE switch 210 that supports the most bands on any given
SKU, although some SKUs will not require all of those RF bands. So,
within a given SKU, the single-product PCB 200 can be populated
with only the components required for a given geographical
region.
[0042] The insertion loss of RFFE switch 210 is primarily a factor
of the resistance of the switch implementation. That is, the
resistance (i.e., R.sub.throw, measured in ohms) between input
terminal 216 and one of the output terminals 218a-218n represents
the resistance across one of the throws 220a-220n in the closed
position. In the switch implementation shown in FIG. 2, each one of
the throws 220a-220n represents a respective circuit branch
emanating from the commonly shared input terminal 216. The power of
an RF signal that is lost between the two terminals of one of the
throws 220a-220n is a directly proportional to the resistance
(R.sub.throw) across the throw.
[0043] During operation, such as a transmission over a
single-carrier RF signal transmission channel, RFFE switch 210
exhibits high insertion loss. The insertion loss of this high
throw-count RFFE switch 210 directly impacts output power, receive
sensitivity, and current consumption of mobile device 100 (FIG. 1).
The transmission power level of RF signals output by antenna 202 is
decreased directly by insertion loss of RFFE switch 210. The
insertion loss exhibited by RFFE switch 210 increases in direct
proportion with increases in the full number of RF bands that PCB
200 supports, and the insertion loss directly impacts the output
power of the mobile device 100. That is, if the full number (N) of
RF bands increases, then the number (N) of throws within RFFE
switch 210 increases, which, in turn, results in greater insertion
loss.
[0044] With reference now to FIGS. 3A and 3B, there are illustrated
two examples of the single-product PCB 200 of FIG. 2 that is
configured to include only components required to support RF bands
for a particular geographical region and that has been modified
according to the low-cost methods for selectively reducing switch
loss, in accordance with one or more embodiments of this
disclosure. The configurations of PCB 200 in FIGS. 3A and 3B show
techniques that enable PCB 200 to support a lower insertion loss on
a RF band path that is used for communication in the SKU by taking
advantage of the fact that certain SKUs do not use certain RF band
paths. In FIG. 3A, PCB 200 is configured to include components
required to support the first RF band and the third through
N.sup.th RF bands, but not second RF band. That is, FIG. 3A
illustrates an example configuration of PCB 200 for a first SKU. In
FIG. 3B, PCB 200 is configured to include components required to
support the first RF band, third RF band, and N.sup.th RF band, but
not the second, fourth, and fifth RF bands. That is, FIG. 3B
illustrates an example configuration of PCB 200 for a second SKU.
It is understood that the configurations of the first and second
SKUs of FIGS. 3A and 3B can be applied in any wireless
communication system. As a particular example in an LTE Protocol
system, in order to configure PCB 200 for placement within a North
America SKU product, components required to support LTE band 41,
band 7, and band 30 would be populated on the PCB, but no
components would be populated for band 40. In North America, LTE
band 40 is not required for wireless communication systems. As
another example, in order to configure PCB 200 for placement within
a China SKU product, components required to support LTE band 40,
band 7, and band 41 would be populated on the PCB, but no
components would be populated for band 30. In China, LTE band 30 is
not required for wireless communication systems. Single-product PCB
design accommodates all of the different geographical SKUs.
[0045] As shown in FIG. 3A, PCB 200 is modified for placement into
a mobile device that is configured according to requirements of the
first SKU. As the first SKU does not require communications over
the second RF band, PCB 200 is modified by depopulating (e.g.,
removing) second band-pass filter 212b. As a result of depopulating
second band-pass filter 212b, Band Path 2 is eliminated
(illustrated by double strike-through style text). That is, second
throw 220b (including second output terminal 218b) is not connected
to any band-pass filter, and thus is not connected to any RF band
path.
[0046] PCB 200 is modified to form a parallel connection between
input terminal 216 and Band Path 1 at first output terminal 218a.
In forming the parallel connection, one end of jumper 302 is
connected to first output terminal 218a, another end of jumper 302
is connected to second output terminal 218b, and first throw 220a
and send throw 220b are closed. As an example, jumper 302 could be
a zero (0) ohm resistor, a series resonant capacitor, a parallel
resonant inductor, or any suitable shunt connector. In at least one
embodiment, first throw 220a and send throw 220b are actuated at
the same time to transition from an open position to a closed
position. In another embodiment, the first throw 220a and send
throw 220b may be actuated separately to commence transition from
the open position to the closed position at different times, but to
remain in the closed position concurrently. The parallel connection
provides at least two parallel branches for routing RF signals
being transmitted from or received at input terminal 216 and Band
Path 1. One of the parallel branches includes input terminal 216 at
one end, first throw 220a in the closed position, and at the other
end, both jumper 302 and first output terminal 218a. The other
parallel branch includes input terminal 216 at one end, second
throw 220b in the closed position, and at the other end, both
jumper 302 and second output terminal 218b.
[0047] The insertion loss of RFFE switch 210 is primarily a factor
of the resistance of the switch implementation. In the switch
implementation shown in FIGS. 3A and 3B, each one of the throws
220a-220n represents a respective circuit branch emanating from the
commonly shared input terminal 216, such that when a parallel
connection is formed between two of the throws 220a and 220b, the
parallel connection (i.e., between input terminal 216 and first
output terminal 218a) exhibits an equivalent resistance
( R EQ = R throw 2 ) ##EQU00001##
that is half of the resistance (R.sub.throw) of one closed throw.
During operation, such as during a transmission over single-carrier
RF signal transmission channel associated with Band Path 1, RFFE
switch 210 of FIG. 3A, which is modified according to the low-cost
methods for selectively reducing switch loss, exhibits a reduced
insertion loss. The reduced insertion loss is a result of the
approximately 50% reduction in resistance.
[0048] As shown in FIG. 3B, PCB 200 is modified for placement into
a mobile device that is configured according to requirements of the
second SKU. As the second SKU does not require communications over
the second, fourth, and fifth RF bands, PCB 200 is modified by
depopulating second band-pass filter 212b, fourth band-pass filter
212d, and fifth band-pass filter 212e. Band Path 2, Band Path 4,
and Band Path 5 are eliminated (illustrated by double
strike-through style text) as a result of depopulating the above
listed three band-pass filters 212b, 212d, and 212e. That is,
second, fourth, and fifth throws 220b, 220d, and 220e are not
connected to any band-pass filter, and thus are not connected to
any RF band path.
[0049] PCB 200 is modified to form a first parallel connection
between input terminal 216 and Band Path 1 at first output terminal
218a, as described above with reference to jumper 302 of FIG. 3A.
Further, PCB 200 is modified to form a second parallel connection
between input terminal 216 and Band Path n at N.sup.th output
terminal 218n. The second parallel connection can be formed in a
variety of ways. According to one embodiment, the second parallel
connection is formed by: connecting one end of a two-terminal
jumper 304b or 304a (respectively) to N.sup.th output terminal
218n; connecting the other end of jumper 304a to an additional
output terminal of RFFE switch 210 (i.e., fourth output terminal
218d or fifth output terminal 218e, respectively) not connected to
any RF band path; closing N.sup.th throw 220n; and closing the
throw (i.e., fourth throw 220d or fifth throw 220e, respectively)
corresponding to the additional output terminal of RFFE switch 210.
According to another embodiment, the second parallel connection is
formed by: connecting one terminal of a multi-terminal jumper 304c
(together 304a and 304b) to N.sup.th output terminal 218n;
connecting other terminals of jumper 304c to multiple additional
output terminals of RFFE switch 210 (i.e., fourth output terminal
218d and fifth output terminal 218e); closing N.sup.th throw 220n;
and closing the throws (i.e., fourth throw 220d and fifth throw
220e) corresponding to the multiple additional output terminals of
RFFE switch 210. The second parallel connection provides at least
two parallel branches for routing RF signals being transmitted from
or received at input terminal 216 and Band Path n. One of the
parallel branches includes input terminal 216 at one end, N.sup.th
throw 220n in the closed position, and at the other end, both
N.sup.th output terminal 218n and jumper 304a, 304b, or 304c. The
second parallel branch includes input terminal 216 at one end,
fifth throw 220e in the closed position, and at the other end, both
fifth output terminal 218e and jumper 304a or 304c. The third
parallel branch includes input terminal 216 at one end, fourth
throw 220d in the closed position, and at the other end, both
fourth output terminal 218d and jumper 304b or 304c.
[0050] When the second parallel connection (i.e., between input
terminal 216 and N.sup.th output terminal 218n) includes three
parallel branches, the second parallel connection exhibits an
equivalent resistance
( R EQ = R throw 3 ) ##EQU00002##
that is one-third of the resistance (R.sub.throw) of one closed
throw. During a transmission over a single-carrier RF signal
transmission channel, RFFE switch 210 of FIG. 3B, which is modified
according to the low-cost methods for selectively reducing switch
loss, exhibits a reduced insertion loss. The reduced insertion loss
is a result of the approximately 331/3% reduction in
resistance.
[0051] Carrier Aggregation (CA) technology is a key technology in
LTE, and is used to implement aggregation of carriers at two
frequencies. Generally, the CA technology may be implemented by
using a radio frequency circuit of a mobile device. Three types of
carrier aggregation modes include intra-band contiguous CA,
intra-band non-contiguous CA, and inter-band CA. Usually, the
inter-band CA is applicable to a scenario of wide frequency
spacing. Since frequency resources vary across global
communications markets, the CA technology focuses on promoting the
capability of a radio frequency circuit to support wider frequency
spacing.
[0052] As shown in FIGS. 3A and 3B, the low-cost methods for
selectively reducing switch loss can be combined with CA
technology. For example, an inter-band CA type scenario can be used
to transceive (i.e., transmit and receive) RF signals via Band Path
1 (associated with the first parallel connection) and via Band Path
n (associated with the second parallel connection) with reduced
insertion loss resulting from the low-cost methods for selectively
reducing switch loss according to embodiments of this
disclosure.
[0053] With reference now to FIG. 4, there is illustrated an
example method 400 for configuring an antenna switch and
selectively reducing switch loss, in accordance with one or more
embodiments. For example, the method 400 can be executed by
manufacturing a PCB 200 (as shown in FIG. 2) and configuring it as
shown in FIGS. 3A-3B. Method 400 begins at the start block, then
proceeds to block 402. At block 402, method 400 includes providing
an RFFE switch 210. For example, as shown in FIG. 2, single-product
PCB 200 is provided, which includes RFFE switch 210 as a component.
In at least one embodiment, RFFE switch 210 is provided, and then
populated onto a PCB in order to complete formation of
single-product PCB 200 of FIG. 2. At block 404, method 400 includes
modifying PCB 200 of FIG. 2 to include only components required to
support RF bands for a particular geographical region or a
particular SKU. More particularly, at block 404, method 400
includes depopulating components from PCB 200 of FIG. 2 that are
not requirements for the particular SKU. As shown in the example of
FIG. 3A, PCB 200 is modified by depopulating (e.g., removing)
second band-pass filter 212b, given that the first SKU does not
require communications over the second RF band. As shown in the
example of FIG. 3B, PCB 200 is modified by depopulating second
band-pass filter 212b, fourth band-pass filter 212d, and fifth
band-pass filter 212e, given that the second SKU does not require
communications over the second, fourth, and fifth RF bands. At
block 406, method 400 includes connecting a first output terminal
to a single-carrier RF band path. For example, as shown in FIG. 3B,
first output terminal 218a is connected to Band Path 1 at first
band-pass filter 212a. At block 408, method 400 includes forming a
parallel connection between the input terminal and the
single-carrier RF band path. For example, as shown in FIG. 3B, a
first parallel connection is formed between input terminal 216 and
Band Path 1 at first output terminal 218a.
[0054] In at least one embodiment, the parallel connection can be
formed by placing (at block 410) a jumper that connects the first
output terminal to and an second additional output terminal, and by
closing (at block 412) first and second throws of the RFFE switch,
which correspond to the first output terminal and additional output
terminal, respectively. For example, as shown in FIG. 3B, the first
parallel connection is formed by placing jumper 302 between first
output terminal 218a and second output terminal 218b and by closing
first throw 220a and second throw 220b.
[0055] At block 414, method 400 includes connecting a third output
terminal of the RFFE switch to a second single-carrier RF band
path. For example, as shown in FIG. 3B, N.sup.th output terminal
218n is connected to Band Path n at N.sup.th band-pass filter 212n.
At block 416, method 400 includes forming a second parallel
connection between the input terminal and the second single-carrier
RF band path. For example, as shown in FIG. 3B, a second parallel
connection is formed between input terminal 216 and Band Path n at
N.sup.th output terminal 218n.
[0056] In at least one embodiment, the second parallel connection
can be formed by placing (at block 418) a jumper that connects the
third output terminal to and an fourth additional output terminal,
and by closing (at block 420) third and fourth throws of the RFFE
switch, which correspond to the third output terminal and fourth
additional output terminal, respectively. For example, as shown in
FIG. 3B, the second parallel connection is formed by placing jumper
304a between N.sup.th output terminal 218n and fifth output
terminal 218e and by closing N.sup.th throw 220n and fifth throw
220e. As another example, as shown in FIG. 3B, the second parallel
connection is formed by connecting three terminals of jumper 304c
to N.sup.th output terminal 218n and both of the fourth and fifth
additional output terminals 218d and 218e and by closing N.sup.th
throw 220n and both of the fourth and fifth throws 220d and 220e,
which correspond to the additional output terminals 218d and 218e,
respectively. The method 400 concludes at the end block.
[0057] In the above-described flowchart of FIG. 4, one or more of
the method processes may be embodied in a computer readable device
containing computer readable code such that a series of steps are
performed when the computer readable code is executed on a
computing device. In some implementations, certain steps of the
methods are combined, performed simultaneously or in a different
order, or perhaps omitted, without deviating from the scope of the
disclosure. Thus, while the method steps are described and
illustrated in a particular sequence, use of a specific sequence of
steps is not meant to imply any limitations on the disclosure.
Changes may be made with regards to the sequence of steps without
departing from the spirit or scope of the present disclosure. Use
of a particular sequence is therefore, not to be taken in a
limiting sense, and the scope of the present disclosure is defined
only by the appended claims.
[0058] Aspects of the present disclosure are described above with
reference to flowchart illustrations and/or block diagrams of
methods, apparatus (systems) and computer program products
according to embodiments of the disclosure. It will be understood
that each block of the flowchart illustrations and/or block
diagrams, and combinations of blocks in the flowchart illustrations
and/or block diagrams, can be implemented by computer program
instructions. Computer program code for carrying out operations for
aspects of the present disclosure may be written in any combination
of one or more programming languages, including an object-oriented
programming language, without limitation. These computer program
instructions may be provided to a processor of a general purpose
computer, special purpose computer, or other programmable data
processing apparatus to produce a machine that performs the method
for implementing the functions/acts specified in the flowchart
and/or block diagram block or blocks. The methods are implemented
when the instructions are executed via the processor of the
computer or other programmable data processing apparatus.
[0059] As will be further appreciated, the processes in embodiments
of the present disclosure may be implemented using any combination
of software, firmware, or hardware. Accordingly, aspects of the
present disclosure may take the form of an entirely hardware
embodiment or an embodiment combining software (including firmware,
resident software, micro-code, etc.) and hardware aspects that may
all generally be referred to herein as a "circuit," "module," or
"system." Furthermore, aspects of the present disclosure may take
the form of a computer program product embodied in one or more
computer readable storage device(s) having computer readable
program code embodied thereon. Any combination of one or more
computer readable storage device(s) may be utilized. The computer
readable storage device may be, for example, but not limited to, an
electronic, magnetic, optical, electromagnetic, infrared, or
semiconductor system, apparatus, or device, or any suitable
combination of the foregoing. More specific examples (a
non-exhaustive list) of the computer readable storage device can
include the following: a portable computer diskette, a hard disk, a
random access memory (RAM), a read-only memory (ROM), an erasable
programmable read-only memory (EPROM or Flash memory), a portable
compact disc read-only memory (CD-ROM), an optical storage device,
a magnetic storage device, or any suitable combination of the
foregoing. In the context of this document, a computer readable
storage device may be any tangible medium that can contain, or
store a program for use by or in connection with an instruction
execution system, apparatus, or device.
[0060] Where utilized herein, the terms "tangible" and
"non-transitory" are intended to describe a computer-readable
storage medium (or "memory") excluding propagating electromagnetic
signals; but are not intended to otherwise limit the type of
physical computer-readable storage device that is encompassed by
the phrase "computer-readable medium" or memory. For instance, the
terms "non-transitory computer readable medium" or "tangible
memory" are intended to encompass types of storage devices that do
not necessarily store information permanently, including, for
example, RAM. Program instructions and data stored on a tangible
computer-accessible storage medium in non-transitory form may
afterwards be transmitted by transmission media or signals such as
electrical, electromagnetic, or digital signals, which may be
conveyed via a communication medium such as a network and/or a
wireless link.
[0061] While the disclosure has been described with reference to
example embodiments, it will be understood by those skilled in the
art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the disclosure. In addition, many modifications may be made to
adapt a particular system, device, or component thereof to the
teachings of the disclosure without departing from the scope
thereof. Therefore, it is intended that the disclosure not be
limited to the particular embodiments disclosed for carrying out
this disclosure, but that the disclosure will include all
embodiments falling within the scope of the appended claims.
[0062] The description of the present disclosure has been presented
for purposes of illustration and description, but is not intended
to be exhaustive or limited to the disclosure in the form
disclosed. Many modifications and variations will be apparent to
those of ordinary skill in the art without departing from the scope
of the disclosure. The described embodiments were chosen and
described in order to best explain the principles of the disclosure
and the practical application, and to enable others of ordinary
skill in the art to understand the disclosure for various
embodiments with various modifications as are suited to the
particular use contemplated.
* * * * *