KR101738270B1 - Diversity receiver front end system with switching network - Google Patents

Abstract

A diversity receiver front end system having a switching network is disclosed. The receiving system may comprise a plurality of amplifiers wherein each of the plurality of amplifiers is arranged along a corresponding one of a plurality of paths between the input of the receiving system and the output of the receiving system and is configured to amplify the signal received at the amplifier . The receiving system may further comprise a switching network comprising one or more single-pole / single-throw switches, each of the switches coupling two of the plurality of paths. The receiving system may further comprise a controller configured to receive a band selection signal and, based on the band selection signal, enables one of the plurality of amplifiers and controls the switching network.

Description

[0001] DIVERSITY RECEIVER FRONT END SYSTEM WITH SWITCHING NETWORK [0002] BACKGROUND OF THE INVENTION [

Cross-reference to related application

This application claims the benefit of U. S. Provisional Application No. 62 / 073,043, filed October 31, 2014, entitled " DIVERSITY RECEIVER FRONT END SYSTEM ", which is expressly incorporated herein by reference in its entirety, U.S. Provisional Application No. 62 / 073,041, entitled " ADAPTIVE MULTIBAND LNA FOR CARRIER AGGREGATION ", filed on October 31, 2014, entitled " DIVERSITY FRONT END SYSTEM WITH VARIABLE- GAIN AMPLIFIERS " No. 14 / 727,739, filed June 9, 2015, entitled " DIVERSITY RECEIVER FRONT END SYSTEM WITH SWITCHING NETWORK ".

Field of invention

The present disclosure relates generally to wireless communication systems having one or more diversity receiving antennas.

In wireless communication applications, size, cost, and performance are examples of factors that may be important for a given product. For example, to increase performance, wireless components such as diversity receive antennas and associated circuits are becoming more and more popular.

In many wireless-frequency (RF) applications, the diversity receive antenna is physically located away from the main antenna. Once both antennas are used, the transceiver can process signals from both antennas to increase data throughput.

According to some implementations, the present disclosure is directed to a receiving system including a plurality of amplifiers. Each of the plurality of amplifiers is arranged to correspond to one of a plurality of paths between the input of the receiving system and the output of the receiving system and is configured to amplify the signal received at the amplifier. The receiving system further includes a switching network including one or more single-pole / single-throw switches. Each of the switches combines two of the plurality of paths. The receiving system further comprises a controller configured to receive a band selection signal, and based on the band selection signal, enables one of the plurality of amplifiers and controls the switching network.

In some embodiments, in response to receiving a band selection signal representative of a single frequency band, the controller may control the switching network to enable one of a plurality of amplifiers corresponding to a single frequency band and to open both of the one or more switches .

In some embodiments, in response to receiving a band selection signal representing a plurality of frequency bands, the controller may enable one of the plurality of amplifiers corresponding to one of the plurality of frequency bands, And may be configured to control the switching network to close at least one of the one or more switches between the paths.

In some embodiments, the receiving system may further include a plurality of phase-shift components. Each of the plurality of phase-shift components is disposed along a corresponding one of the plurality of paths and includes a signal passing through the phase-shift component to increase the impedance for a frequency band corresponding to another of the plurality of paths Phase-shifted. In some embodiments, each of the plurality of phase-shift components may be disposed between the switching network and the input. In some embodiments, at least one of the plurality of phase-shift components is tuned to phase-shift the signal passing through the tunable phase-shift component by an amount controlled by the phase-shift tuning signal received from the controller And may include possible phase-shift components. In some embodiments, the controller can be configured to generate a phase-shift tuning signal based on the band selection signal.

In some embodiments, the receiving system may further include a plurality of impedance matching components. Each of the plurality of impedance matching components may be arranged along a corresponding one of the plurality of paths and configured to reduce the noise figure of the corresponding one of the plurality of paths. In some embodiments, each of the plurality of impedance matching components may be disposed between a switching network and a corresponding one of the plurality of amplifiers. In some embodiments, at least one of the plurality of impedance matching components may comprise a tunable impedance matching component configured to indicate an impedance controlled by an impedance tuning signal received from the controller. In some embodiments, the controller may be configured to generate an impedance tuning signal based on the band selection signal.

In some embodiments, the receiving system may further comprise a multiplexer configured to divide the input signal received at the input into a plurality of signals in each of a plurality of frequency bands propagated along a plurality of paths.

In some embodiments, at least one of the plurality of amplifiers may include a dual-stage amplifier.

In some embodiments, the controller may be configured to enable one of the plurality of amplifiers and disable the other of the plurality of amplifiers.

In some implementations, this disclosure is directed to a wireless-frequency (RF) module that includes a packaging substrate configured to accommodate a plurality of components. The RF module further includes a receiving system implemented on a packaging substrate. The receiving system includes a plurality of amplifiers. Each of the plurality of amplifiers is arranged to correspond to one of a plurality of paths between the input of the receiving system and the output of the receiving system and is configured to amplify the signal received at the amplifier. The receiving system further includes a switching network including one or more single-pole / single-throw switches. Each of the switches combines two of the plurality of paths. The receiving system further comprises a controller configured to receive a band selection signal, and based on the band selection signal, enables one of the plurality of amplifiers and controls the switching network.

In some embodiments, the RF module may be a diversity receiver front-end module (FEM).

In some embodiments, the receiving system may further include a plurality of phase-shift components. Each of the plurality of phase-shift components is disposed along a corresponding one of the plurality of paths and includes a signal passing through the phase-shift component to increase the impedance for a frequency band corresponding to another of the plurality of paths Phase-shifted.

According to some teachings, the present disclosure is directed to a wireless device including a first antenna configured to receive a first radio-frequency (RF) signal. The wireless device further includes a first front-end module (FEM) in communication with the first antenna. The first FEM includes a packaging substrate configured to receive a plurality of components. The first FEM further comprises a receiving system implemented on a packaging substrate. The receiving system includes a plurality of amplifiers. Each of the plurality of amplifiers is arranged to correspond to one of a plurality of paths between the input of the receiving system and the output of the receiving system and is configured to amplify the signal received at the amplifier. The receiving system further includes a switching network including one or more single-pole / single-throw switches. Each of the switches combines two of the plurality of paths. The receiving system further comprises a controller configured to receive a band selection signal, and based on the band selection signal, enables one of the plurality of amplifiers and controls the switching network. The wireless device further includes a transceiver configured to receive a processed version of the first RF signal from the output via the cable and to generate data bits based on the processed version of the first RF signal.

In some implementations, the wireless device may further comprise a second antenna configured to receive a second radio-frequency (RF) signal and a second FEM in communication with the first antenna. The transceiver may also be configured to receive the processed version of the second RF signal from the output of the second FEM and generate a data bit based on the processed version of the second RF signal.

In some implementations, the receiving system may further include a plurality of phase-shift components. Each of the plurality of phase-shift components is disposed along a corresponding one of the plurality of paths and includes a signal passing through the phase-shift component to increase the impedance for a frequency band corresponding to another of the plurality of paths Phase-shifted.

For the purpose of summarizing the disclosure, certain aspects, advantages and novel features of the invention have been described herein. It is to be understood that not necessarily all of these advantages need be achieved in accordance with any particular embodiment of the present invention. Accordingly, the present invention may be embodied or carried out in such a manner that one advantage or one group of advantages taught herein may be achieved or optimized without necessarily having to otherwise observe or implicitly observe the advantages herein.

1 shows a wireless device having a communication module coupled to a primary antenna and a diversity antenna.
Figure 2 shows a diversity receiver (DRx) configuration including a DRx front-end module (FEM).
Figure 3 illustrates, in some embodiments, that a diversity receiver (DRx) configuration may include a DRx module having a plurality of paths corresponding to a plurality of frequency bands.
Figure 4 illustrates that, in some embodiments, the diversity receiver configuration may include a diversity RF module with fewer amplifiers than the diversity receiver (DRx) module.
Figure 5 illustrates, in some embodiments, that the diversity receiver configuration may include a DRx module with a single-pole / single-throw switch.
6 illustrates that, in some embodiments, the diversity receiver configuration may include a DRx module with a tunable phase-shift component.
Figure 7 shows an embodiment of a flow diagram representation of a method of processing an RF signal.
Figure 8 illustrates a module having one or more features described herein.
9 illustrates a wireless device having one or more features described herein.

The introduction provided herein, if any, is merely for convenience and does not necessarily affect the scope or meaning of the claimed invention.

Figure 1 illustrates a wireless device 100 having a communication module 110 coupled to a primary antenna 130 and a diversity antenna 140. [ The communication module 110 (and its constituent components) may be controlled by the controller 120. The communication module 110 includes a transceiver 112 configured to convert between an analog radio-frequency (RF) signal and a digital data signal. For that purpose, the transceiver 112 may be a digital-to-analog converter, an analog-to-digital converter, a local oscillator for modulating a baseband analog signal to a carrier frequency or demodulating a baseband analog signal from a carrier frequency, A baseband processor that converts between samples and data bits (e.g., voice or other types of data), or other components.

The communication module 110 further includes an RF module 114 coupled between the primary antenna 130 and the transceiver 112. The RF module 114 may be referred to as a front-end module (FEM) because the RF module 114 may physically be proximate to the primary antenna 130 to reduce attenuation due to cable loss . The RF module 114 may perform processing on an analog signal received from the transceiver 112 for transmission via the primary antenna 130 or received from the primary antenna 130 for the transceiver 112. [ For this purpose, the RF module 114 may include a filter, a power amplifier, a band selection switch, a matching circuit, and other components. Similarly, communication module 110 includes a diversity RF module 116 coupled between a transceiver 112 and a diversity antenna 140 that perform similar processing.

When a signal is transmitted to the wireless device, the signal may be received at both the primary antenna 130 and the diversity antenna 140. The primary antenna 130 and the diversity antenna 140 are physically spaced apart so that the signals at the primary antenna 130 and the diversity antenna 140 are received with different characteristics. For example, in one embodiment, the primary antenna 130 and the diversity antenna 140 may receive signals having different attenuation, noise, frequency response, or phase shifts. The transceiver 112 may utilize both signals having different characteristics to determine the data bits corresponding to the signals. In some implementations, the transceiver 112 selects between the primary antenna 130 and the diversity antenna 140 based on the characteristics, such as selecting the antenna with the highest signal-to-noise ratio. In some implementations, transceiver 112 combines the signals from primary antenna 130 and diversity antenna 140 to increase the signal-to-noise ratio of the combined signal. In some implementations, the transceiver 112 processes signals to perform multiple-input / multiple-output (MIMO) communications.

Because the diversity antenna 140 is physically spaced from the primary antenna 130, the diversity antenna 140 may be coupled to the communication module (not shown) by a transmission line 135, such as a cable or a printed circuit board 110). In some implementations, the transmission line 135 has a loss and attenuates the signal received at the diversity antenna 140 before it reaches the communication module 110. Thus, in some implementations, gain is applied to the signal received at the diversity antenna 140, as described below. The gain (and other analog processing, such as filtering) may be applied by a diversity receiver module. Such a diversity receiver module may be physically located in proximity to the diversity antenna 140, and thus may be referred to as a diversity receiver front-end module.

2 shows a diversity receiver (DRx) configuration 200 that includes a DRx front-end module (FEM) The DRx configuration 200 includes a diversity antenna 140 configured to receive a diversity signal and provide a diversity signal to the DRx FEM 210. [ The DRx FEM 210 is configured to perform processing relating to the diversity signal received from the diversity antenna 140. [ For example, the DRx FEM 210 may be configured to filter the diversity signal into one or more active frequency bands, for example, as indicated by the controller 120. As another example, the DRx FEM 210 may be configured to amplify the diversity signal. For this purpose, the DRx FEM 210 may include filters, low-noise amplifiers, band selection switches, matching circuits, and other components.

The DRx FEM 210 sends the processed diversity signal to a downstream module such as a diversity RF (D-RF) module 116 that provides an additional processed diversity signal to the transceiver 112, 135). The diversity RF module 116 (and, in some implementations, the transceiver) is controlled by the controller 120. In some implementations, the controller 120 may be implemented within the transceiver 112.

3 illustrates that, in some embodiments, the diversity receiver (DRx) configuration 300 may include a DRx module 310 having a plurality of paths corresponding to a plurality of frequency bands. The DRX configuration 300 includes a diversity antenna 140 configured to receive a diversity signal. In some implementations, the diversity signal may be a single-band signal comprising data modulated in a single frequency band. In some implementations, the diversity signal may be a multi-band signal (also referred to as an inter-band carrier aggregation signal) comprising data modulated in a plurality of frequency bands.

The DRx module 310 provides an input for receiving a diversity signal from the diversity antenna 140 and a processed diversity signal to the transceiver 330 (via the transmission line 135 and the diversity RF module 320) Lt; / RTI > The input of the DRx module 310 is provided as an input of the first multiplexer 311. The first multiplexer (MUX) 311 includes a plurality of multiplexer outputs, each of which corresponds to a path between the input and the output of the DRx module 310. Each of the paths may correspond to each frequency band. The output of the DRx module 310 is provided by the output of the second multiplexer 312. The second multiplexer 312 includes a plurality of multiplexer inputs, each of which corresponds to one of the paths between the input and the output of the DRx module 310.

The frequency bands may be cellular frequency bands, such as Universal Mobile Telecommunications System (UMTS) frequency bands. For example, the first frequency band may be a UMTS downlink or "Rx" band 2 between 1930 megahertz (MHZ) and 1990 MHz, the second frequency band may be a UMTS downlink between 869 MHz and 894 MHz "Rx" band 5. Other downlink frequency bands may be used, such as those described in Table 1 below or other non-UMTS frequency bands.

In some implementations, the DRx module 310 includes a DRx controller 302 that receives signals from a controller 120 (also referred to as a communications controller), and based on the received signals, Or < / RTI > In some implementations, the DRx module 310 does not include the DRx controller 302 and the controller 120 selectively activates one or more of the plurality of paths directly.

As noted above, in some implementations, the diversity signal is a single-band signal. Thus, in some implementations, the first multiplexer 311 may be configured to receive a signal from the DRX controller 302, such as a single signal that routes the diversity signal to one of a plurality of paths corresponding to the frequency band of the single- Pole / multiple-throw (SPMT) switch. The DRx controller 302 may generate a signal based on the band selection signal received by the DRx controller 302 from the communications controller 120. [ Similarly, in some implementations, the second multiplexer 312 receives a signal from the corresponding one of the plurality of paths corresponding to the frequency band of the single-band signal based on the signal received from the DRx controller 302 It is an SPMT switch that routes.

As noted above, in some implementations, the diversity signal is a multi-band signal. Thus, in some implementations, the first multiplexer 311 is operable to receive at least two of the plurality of paths corresponding to two or more frequency bands of the multi-band signal based on the splitter control signal received from the DRx controller 302 Is a signal splitter that routes diversity signals. The function of the signal splitter may be implemented as an SPMT switch, a diplexer filter, or some combination thereof. Similarly, in some implementations, the second multiplexer 312 may select one or more of a plurality of paths corresponding to two or more frequency bands of the multi-band signal based on the combiner control signal received from the DRx controller 302 Lt; / RTI > The function of the signal combiner may be implemented as an SPMT switch, a diplexer filter, or some combination thereof. The DRX controller 302 may generate a splitter control signal and a combiner control signal based on the band selection signal received by the DRx controller 302 from the communication controller 120. [

Thus, in some implementations, the DRx controller 302 may selectively enable one or more of the plurality of paths based on the band selection signal received by the DRx controller 302 (e.g., from the communications controller 120) . In some implementations, the DRX controller 302 is configured to selectively enable one or more of the plurality of paths by sending a splitter control signal to the signal splitter and sending a combiner control signal to the signal combiner.

The DRx module 310 includes a plurality of bandpass filters 313a-313d. Each of the bandpass filters 313a-313d is arranged to correspond to one of the plurality of paths and is configured to filter the signal received at the bandpass filter into a respective one of the plurality of paths . In some implementations, the bandpass filters 313a-313d may also filter the received signal at the bandpass filter into a downlink frequency sub-band of the respective one of the plurality of paths . The DRx module 310 includes a plurality of amplifiers 314a-314d. Each of the amplifiers 314a-314d is arranged to correspond to one of the plurality of paths and is configured to amplify the signal received at the amplifier.

In some implementations, amplifiers 314a-314d are narrowband amplifiers configured to amplify signals within the respective frequency bands of the path in which the amplifiers are located. In some implementations, the amplifiers 314a-314d are controllable by the DRx controller 302. For example, in some implementations, each of the amplifiers 314a-314d includes an enable / disable input and is enabled (or disabled) based on the received amplifier enable signal and the enable / disable input . The amplifier enable signal may be transmitted by the DRX controller 302. Thus, in some implementations, the DRX controller 302 may transmit one or more of the plurality of paths by sending an amplifier enable signal to one or more of the amplifiers 314a-314d, respectively, disposed along one or more of the plurality of paths Lt; / RTI > In this implementation, rather than being controlled by the DRX controller 302, the first multiplexer 311 may be a signal splitter that routes diversity signals to each of the plurality of paths, and the second multiplexer 312 may be a multiplexer Lt; / RTI > may be a signal combiner that combines the signals from each of the plurality of input signals. However, in an implementation in which the DRX controller 302 controls the first multiplexer 311 and the second multiplexer 312, the DRx controller 302 may also be coupled to a particular amplifier 314a-314d Can be enabled (or disabled).

In some implementations, the amplifiers 314a-314d are variable-gain amplifiers (VGAs). Thus, in some implementations, the DRx module 310 includes a plurality of variable-gain amplifiers (VGAs), each of which is arranged along a corresponding one of a plurality of paths and receives signals received at the VGA, Amplified by a gain controlled by an amplifier control signal received from the amplifier 302.

The gain of the VGA may be bypassable, step-variable, or continuously-variable. In some implementations, at least one of the VGAs includes a fixed-gain amplifier and a bypass switch that can be controlled by an amplifier control signal. The bypass switch closes the line from the input of the fixed-gain amplifier (at the first position) to the output of the fixed-gain amplifier, allowing the signal to bypass the fixed-gain amplifier. The bypass switch opens the line between the input and the output (in the second position) and passes the signal through the fixed-gain amplifier. In some implementations, when the bypass switch is in the first position, the fixed-gain amplifier is disabled or otherwise reconfigured to accommodate the bypass mode.

In some implementations, at least one of the VGAs includes a step-variable gain amplifier configured to amplify the signal received at the VGA with one of a plurality of configured quantities indicated by the amplifier control signal. In some implementations, at least one of the VGAs includes a continuous-variable gain amplifier configured to amplify the signal received at the VGA with a gain proportional to the amplifier control signal.

In some implementations, the amplifiers 314a-314d are variable-current amplifiers (VCAs). The current drawn by the VCA may be bypassable, step-variable, or continuous-variable. In some implementations, at least one of the VCAs includes a fixed-current amplifier and a bypass switch controllable by the amplifier control signal. The bypass switch closes the line between the input of the fixed-current amplifier (at the first position) and the output of the fixed-current amplifier, allowing the signal to bypass the fixed-current amplifier. The bypass switch opens the line between the input (at the second position) and the output, allowing the signal to pass through the fixed-current amplifier. In some implementations, when the bypass switch is in the first position, the fixed-current amplifier is disabled or otherwise reconfigured to accommodate the bypass mode.

In some implementations, at least one of the VCAs includes a step-variable current amplifier configured to amplify a signal received at the VCA by pulling one of a plurality of configured quantities indicated by the amplifier control signal. In some implementations, at least one of the VCAs includes a continuous-variable current amplifier configured to amplify the signal received at the VCA by drawing a current proportional to the amplifier control signal.

In some implementations, amplifiers 314a-314d are fixed-gain, fixed-current amplifiers. In some implementations, the amplifiers 314a-314d are fixed-gain, variable-current amplifiers. In some implementations, amplifiers 314a-314d are variable-gain, fixed-current amplifiers. In some implementations, the amplifiers 314a-314d are variable-gain, variable-current amplifiers.

In some implementations, the DRX controller 302 generates the amplifier control signal (s) based on the quality of service metric of the input signal received at the input. In some implementations, the DRx controller 302 is operable to receive the amplifier control signal (s) based on a signal received from the communication controller 120, which may eventually be based on a quality of service (QoS) . The QoS metric of the received signal may be based, at least in part, on the diversity signal received at the diversity antenna 140 (e.g., the input signal received at the input). The QoS metric of the received signal may be further based on the signal received at the primary antenna. In some implementations, the DRX controller 302 generates the amplifier control signal (s) based on the QoS metric of the diversity signal without receiving a signal from the communication controller 120.

In some implementations, the QoS metric includes signal strength. As another example, the QoS metric may include a bit error rate, data throughput, transmission delay, or any other QoS metric.

The DRx module 310 receives the diversity signal from the diversity antenna 140 and the processed diversity signal (via the transmission line 135 and the diversity RF module 320) And provides the output to the transceiver 330. Diversity RF module 320 receives the processed diversity signal on transmission line 135 and performs further processing. In particular, the processed diversity signal is split by the diversity RF multiplexer 321 into signals that are split or split or routed by the corresponding band-pass filters 323a-323d and corresponding amplifiers 324a- 0.0 > 324d. ≪ / RTI > The output of each of the amplifiers 324a-324d is provided to the transceiver 330. [

The diversity RF multiplexer 321 may be controlled by the controller 120 (either directly or through an on-chip diversity RF controller) to selectively activate one or more of the paths. Similarly, the amplifiers 324a-324d may be controlled by the controller 120. [ For example, in some implementations, each of the amplifiers 324a-324d includes an enable / disable input and is enabled (or disabled) based on the amplifier enable signal. In some implementations, amplifiers 324a-324d are controlled by an amplifier control signal received from controller 120 (or an on-chip diversity RF controller controlled by controller 120) Gain amplifier (VGA) that amplifies the signal to gain. In some implementations, the amplifiers 324a-324d are variable-current amplifiers (VCAs).

The number of bandpass filters in the DRx configuration 300 is doubled by the DRx module 310 that is added to the receiver chain that already includes the diversity RF module 320. Thus, in some implementations, bandpass filters 323a-323d are not included in the diversity RF module 320. [ Rather, the bandpass filters 313a-313d of the DRx module 310 are used to reduce the strength of the out-of-band blockers. The automatic gain control (AGC) table of the diversity RF module 320 also indicates the amount of gain provided by the amplifiers 324a-324d of the diversity RF module 320 to the DRx module By the amount of gain provided by the amplifiers 314a-314d of the amplifier 310. [

For example, if the DRx module gain is 15 dB and the receiver sensitivity is -100 dBm, the diversity RF module 320 will see a sensitivity of -85 dBm. If the closed loop AGC of the diversity RF module 320 is active, the gain will automatically drop by 15 dB. However, both the signal components and the out-of-band blockers are amplified and received by 15 dB. Thus, the 15 dB gain drop of the diversity RF module 320 may also be accompanied by a 15 dB increase in its linearity. In particular, the amplifiers 324a-324d of the diversity RF module 320 may be designed such that the linearity of the amplifiers increases with a gain reduction (or current increase).

In some implementations, the controller 120 controls the gains (and / or current) of the amplifiers 314a-314d of the DRx module 310 and the amplifiers 324a-324d of the diversity RF module 320. Controller 120 is responsive to increasing the amount of gain provided by amplifiers 314a-314d of the DRx module 310, as in the example above, to amplifiers 324a-324d Can be reduced. Thus, in some implementations, the controller 120 may control the amplifiers 324a-324d of the diversity RF module 320 based on the amplifier control signals (for the amplifiers 314a-314d of the DRx module 310) To control the gain of one or more downstream amplifiers 324a-324d coupled to the output (via the transmission line 135) (of the DRx module 310) to generate a downstream amplifier control signal. In some implementations, the controller 120 also controls the gain of other components of the wireless device, such as an amplifier in the front-end module (FEM), based on the amplifier control signal.

As noted above, in some implementations, bandpass filters 323a-323d are not included. Thus, in some implementations, at least one of the downstream amplifiers 324a-324d is coupled to the output (via the transmission line 135) (of the DRx module 310) without passing through a downstream bandpass filter.

4 illustrates that, in some embodiments, the diversity receiver configuration 400 may include a diversity RF module 420 having fewer amplifiers than the diversity receiver (DRx) module 310. The diversity receiver configuration 400 includes a diversity antenna 140 and a DRx module 310 as described above with respect to FIG. The output of the DRx module 310 is different from the diversity RF module 320 of Figure 3 in that the diversity RF module 420 of Figure 4 includes fewer amplifiers than the DRx module 310. [ And is transmitted to the RF module 420 through the transmission line 135.

As noted above, in some implementations, the diversity RF module 420 does not include a bandpass filter. Thus, in some implementations, one or more of the amplifiers 424 of the diversity RF module 420 need not be band-specific. In particular, the diversity RF module 420 may include one or more paths, each path including an amplifier 424 that is not 1-to-1 mapped to the paths of the DRx module 310. This mapping of paths (or a corresponding amplifier) may be stored in the controller 120.

Thus, the DRx module 310 includes multiple paths, each path corresponding to a frequency band, while the diversity RF module 420 may include one or more paths that do not correspond to a single frequency band.

In some implementations (shown in FIG. 4), diversity RF module 420 includes a single wideband amplifier 424 that amplifies the signal received from transmission line 135 and provides the amplified signal to multiplexer 421 Output. Multiplexer 421 includes a plurality of multiplexer outputs, each output corresponding to a respective frequency band. In some implementations, the diversity RF module 420 does not include any amplifiers.

In some implementations, the diversity signal is a single-band signal. Thus, in some implementations, the multiplexer 421 is an SPMT switch that routes the diversity signal to one of a plurality of outputs corresponding to the frequency band of the single-band signal based on the signal received from the controller 120. In some implementations, the diversity signal is a multi-band signal. Thus, in some implementations, the multiplexer 421 may multiplex the diversity signal (s) to two or more of the plurality of outputs corresponding to two or more frequency bands of the multi-band signal based on the splitter control signal received from the controller 120 Lt; / RTI > In some implementations, the diversity RF module 420 may be combined with the transceiver 330 as a single module.

In some implementations, the diversity RF module 420 includes a plurality of amplifiers, each of which corresponds to a set of frequency bands. The signal from the transmission line 135 may be transmitted in a band splitter that outputs a high frequency to the high frequency amplifier along the first path and a low frequency to the low frequency amplifier along the second path. The output of each of the amplifiers may be provided to a multiplexer 421 that is configured to route the signal to a corresponding input of the transceiver 330.

Figure 5 illustrates that, in some embodiments, the diversity receiver configuration 500 may include a DRx module 510 with a single-pole / single-throw switch 519. [ The DRx module 510 includes two paths from the input of the DRx module 510 coupled to the antenna 140 and the output of the DRx module 510 coupled to the transmission line 135. The DRx module 510 includes a plurality of amplifiers 514a-514b, each of the plurality of amplifiers 514a-514b being arranged along a corresponding one of the plurality of paths and amplifying the signal received at the amplifier . In some implementations, as shown in FIG. 5, at least one of the plurality of amplifiers includes a dual-stage amplifier.

In the DRx module 510 of FIG. 5, the signal splitter and bandpass filters are implemented as a diplexer 511. The diplexer 511 includes an input coupled to the antenna 140, a first output coupled to a phase-shift component 527a disposed along a first path, a second output coupled to a second phase- And a second output coupled to component 527b. At the first output, the diplexer 511 outputs the signal received at the input (e.g., from the antenna 140) filtered in the first frequency band. At the second output, the diplexer 511 outputs the received signal at the input filtered to the second frequency band. In some implementations, the diplexer 511 may multiplex the input signal received at the input of the triplexer, the quadruplexer, or the DRx module 510 into a plurality of Lt; RTI ID = 0.0 > multiplexers < / RTI >

In some implementations, an output multiplexer or other signal combiner placed at the output of the DRx module, such as the second multiplexer 312 of FIG. 3, may degrade the performance of the DRx module when receiving a single-band signal. For example, the output multiplexer may attenuate noise or introduce noise to a single-band signal. In some implementations, when a plurality of amplifiers, such as amplifiers 314a-314d in FIG. 3, are enabled simultaneously to support multi-band signals, each amplifier not only has in-band noise for each of the other plurality of bands Out-of-band noise can be introduced.

The DRx module 510 of FIG. 5 solves some of these challenges. The DRx module 510 includes a single-pole / single-throw (SPST) switch 519 that couples the first path to the second path. To operate in the single-band mode for the first frequency band, the switch 519 is placed in the open position, the first amplifier 514a is enabled, and the second amplifier 514b is disabled. Thus, the single-band signal in the first frequency band propagates from the antenna 140 to the transmission line 135 along the first path without switching loss. Similarly, to operate in the single-band mode for the second frequency band, the switch 519 is placed in the open position, the first amplifier 514a is disabled, and the second amplifier 514b is enabled. Thus, the single-band signal in the second frequency band propagates from the antenna 140 to the transmission line 135 along the second path without switching loss.

The switch 519 is placed in the closed position and the first amplifier 514a is enabled and the second amplifier 514b is enabled to operate in the multi- Lt; / RTI > Thus, the first frequency band portion of the multi-band signal propagates along the first path through the first phase-shift component 527a, the first impedance matching component 526a, and the first amplifier 514a. The first frequency band portion is prevented from propagating backward along the second path by the second phase-shift component 527b across the switch 519. [ In particular, the second phase-shift component 527a phase-shifts the first frequency-band portion of the signal passing through the second phase-shift component 527b to maximize (or at least increase) the impedance in the first frequency band .

The second frequency band portion of the multi-band signal propagates through the second phase-shift component 527b along the second path and traverses the switch 519 along the first path to the first impedance matching component 526a And the first amplifier 314a. The second frequency band portion is prevented from propagating backward along the first path by the first phase-shift component 527a. In particular, the first phase-shift component 527a phase-shifts the second frequency band portion of the signal passing through the first phase-shift component 527a to maximize (or at least increase) the impedance in the second frequency band .

Each of the paths can be characterized by noise figure and gain. The noise figure of each path is a representation of the deterioration of the signal-to-noise ratio (SNR) caused by the amplifier and impedance matching components 526a-526b placed along the path. In particular, the noise figure of each path is the difference in decibels (dB) between the SNR at the input of the impedance matching components 526a-526b and the SNR at the output of the amplifiers 314a-314b. Thus, the noise figure is a measure of the difference between the noise output of the amplifier and the noise output of an "ideal" amplifier (which does not produce noise) with the same gain.

The noise figure for each path can be different for each frequency band. For example, the first path may have a first noise figure for the first frequency band and a second noise figure for the second frequency band. The noise figure and gain for each path (in each frequency band) may depend, at least in part, on the impedance (in each frequency band) of the impedance matching components 526a-526b. Thus, it may be beneficial for the impedance of the impedance matching components 526a-526b to minimize (or reduce) the noise figure of each path.

In some implementations, the second impedance matching component 526b represents an impedance that minimizes (or reduces) the noise figure for the second frequency band. In some implementations, the first impedance matching component 526a minimizes (or reduces) the noise figure for the first frequency band. Because the second frequency band portion of the multi-band signal may be partially propagated along the first portion, in some implementations, the first impedance matching component 526a may provide a noise figure for the first band and a noise figure for the second band Minimize (or reduce) the metric including the noise figure.

Impedance matching components 526a-526b may be implemented as passive circuits. In particular, impedance matching components 526a-526b may be implemented as RLC circuits and may include one or more passive components such as resistors, inductors, and / or capacitors. The passive components may be connected in parallel and / or in series and may be connected between the output of phase-shift components 527a-527b and the inputs of amplifiers 514a-514b or connected to the outputs of phase-shift components 527a-527b And may be connected between the ground voltage.

Similarly, phase-shift components 527a-527b may be implemented as passive circuits. In particular, phase-shift components 527a-527b may be implemented as LC circuits and may include one or more passive components, such as inductors and / or capacitors. The passive components may be connected in parallel and / or in series and may be connected between the output of the diplexer 511 and the input of the impedance matching components 526a-526b or between the output of the diplexer 511 and the ground voltage Can be connected.

Figure 6 illustrates that, in some embodiments, the diversity receiver configuration 600 may include a DRx module 610 with tunable phase-shift components 627a-627d. Each of the tunable phase-shift components 627a-627d may be configured to phase-shift the signal passing through the tunable phase-shift component by an amount controlled by the phase-shift tuning signal received from the controller.

The diversity receiver configuration 600 includes a DRx module 610 having an input coupled to the antenna 140 and an output coupled to the transmission line 135. The DRx module 610 includes a number of paths between the inputs and outputs of the DRx module 610. Each of the paths includes a multiplexer 311, bandpass filters 313a-313d, tunable phase-shift components 627a-627d, a switching network 612, tunable impedance matching components 626a-626d, (314a-314d). As described above, the amplifiers 314a-314d may be variable-gain amplifiers and / or variable-current amplifiers.

Tunable phase-shift components 627a-627d may include one or more variable components, such as inductors and capacitors. The variable components may be connected in parallel and / or in series and connected between the output of the multiplexer 311 and the input of the switching network 612 or may be connected between the output of the multiplexer and the ground voltage.

The tunable impedance matching components 626a-626d may be a tunable T-circuit, a tunable PI-circuit, or any other tunable matching circuit. The tunable impedance matching components 626a-626d may include one or more variable components, such as resistors, inductors, and capacitors. The variable component may be connected in parallel and / or in series and may be connected between the output of the switching network 612 and the input of the amplifiers 314a-314d or may be connected between the output of the switching network 612 and the ground voltage .

The DRX controller 602 is configured to selectively enable one or more of a plurality of paths between an input and an output. In some implementations, the DRX controller 602 is configured to selectively enable one or more of the plurality of paths based on the band selection signal received by the DRx controller 602 (e.g., from a communications controller). The DRX controller 602 may be enabled to enable or disable the amplifiers 314a-314d, for example, to control the multiplexer 311 and / or the switching network 612, .

In some implementations, the DRX controller 602 controls the switching network 612 based on the band selection signal. The switching network includes a plurality of SPST switches, each of the switches coupling two of the plurality of paths. The DRX controller 602 may send a switching signal (or a plurality of switching signals) to the switching network to open or close a plurality of SPST switches. For example, if the band selection signal indicates that the input signal comprises a first frequency band and a second frequency band, the DRx controller 602 may close the switch between the first path and the second path. If the band selection signal indicates that the input signal includes the second frequency band and the fourth frequency band, the DRx controller 602 may close the switch between the second path and the fourth path. If the band selection signal indicates that the input signal comprises a first frequency band, a second frequency band, and a fourth frequency band, the DRx controller 602 may close both switches (and / or the first and second paths) The switch between the path and the switch between the first path and the fourth path). If the band selection signal indicates that the input signal comprises a second frequency band, a third frequency band, and a fourth frequency band, then the DRx controller 602 may switch between the second path and the third path, (And / or switch between the second path and the third path and switch between the second path and the fourth path can be closed).

In some implementations, the DRX controller 602 is configured to tune the tunable phase-shift components 627a-627d. In some implementations, the DRX controller 602 tunes the tunable phase-shift components 627a-627d based on the band selection signal. For example, the DRX controller 602 may tune the tunable phase-shift components 627a-627d based on a look-up table that associates the frequency band (or set of frequency bands) indicated by the band select signal with the tuning parameters have. Thus, in response to the band selection signal, the DRX controller 602 sends a phase-shift tuning signal to the tunable phase-shift components 627a-627d of each active path to provide a tunable phase- (Or its variable components).

The DRx controller 602 may be configured to tune the tunable phase-shift component 627a-627d of each active path to maximize (or at least increase) the impedance in the frequency bands corresponding to the other active paths have. Thus, if the first path and the third path are active, the DRx controller 602 can tune the first phase-shift component 627a to maximize (or at least increase) the impedance in the third frequency band If the first and fourth paths are active, the DRx controller 602 may tune the first phase-shift component 627a to maximize (or at least increase) the impedance in the fourth frequency band.

In some implementations, the DRX controller 602 is configured to tune the tunable impedance matching components 626a-626d. In some implementations, the DRX controller 602 tunes the tunable impedance matching components 626a-626d based on the band selection signal. For example, the DRX controller 602 can tune the tunable impedance matching components 626a-626d based on a lookup table that associates the frequency band (or frequency band set) indicated by the band select signal with the tuning parameters have. Thus, in response to the band select signal, the DRX controller 602 may send an impedance tuning signal to the tunable impedance matching component 626a-626d of the path having the active amplifier according to the tuning parameter.

In some implementations, the DRX controller 602 includes a tunable impedance matching component 626a-626d of the path with an active amplifier to minimize (or reduce) the metric including the noise figure for the corresponding frequency band of each active path, Lt; / RTI >

In various implementations, one or more of the tunable phase-shift components 627a-627d or the tunable impedance matching components 626a-626d may be replaced by a fixed component that is not controlled by the DRx controller 602 .

FIG. 7 illustrates an embodiment of a flow diagram representation of a method 700 for processing an RF signal. In some implementations (and as described below by way of example), the method 700 is performed by a controller, such as the DRx controller 602 of FIG. In some implementations, the method 700 is performed by processing logic, including hardware, firmware, software, or a combination thereof. In some implementations, the method 700 is performed by a processor executing code stored in a non-volatile computer-readable medium (e.g., memory). In summary, the method 700 includes receiving a band selection signal and routing the received RF signal along one or more paths to process the received RF signal.

The method 700 begins at block 710 with the controller receiving a band selection signal. The controller may receive a band selection signal from another controller or a band selection signal from a cellular base station or other external source. The band selection signal may indicate one or more frequency bands in which the wireless device transmits and receives the RF signal. In some implementations, the band selection signal represents a set of frequency bands for carrier aggregation communication.

At block 720, the controller sends an amplifier enable signal to the amplifier of the DRx module based on the band selection signal. In some implementations, the band select signal represents a single frequency band and the controller transmits an amplifier enable signal to enable an amplifier disposed along a path corresponding to a single frequency band. The controller may send an amplifier enable signal to disable other amplifiers arranged along different paths corresponding to different frequency bands. In some implementations, the band selection signal represents a plurality of frequency bands and the controller transmits an amplifier enable signal to enable the amplifiers arranged along one of the paths corresponding to one of the plurality of frequency bands. The controller may send an amplifier enable signal to disable other amplifiers. In some implementations, the controller enables an amplifier disposed along a path corresponding to the lowest frequency band.

At block 730, the controller sends a switching signal to control the switching network of single-pole / single-throw (SPST) switches based on the band selection signal. The switching network includes a plurality of SPST switches coupling a plurality of paths corresponding to the plurality of frequency bands. In some implementations, the band select signal represents a single frequency band and the controller transmits a switching signal that opens both SPST switches. In some implementations, the band selection signal represents a plurality of frequency bands and the controller transmits a switching signal that closes one or more of the SPST switches to combine paths corresponding to the plurality of frequency bands.

At block 740, the controller sends a tuning signal to one or more tunable components based on the band selection signal. The tunable component may include one or more of a plurality of tunable phase-shift components or a plurality of tunable impedance matching components. The controller may tune the tunable components based on a lookup table that associates the frequency band (or set of frequency bands) indicated by the band select signal with the tuning parameters. Thus, in response to the band selection signal, the DRx controller can send a tuning signal to the tunable component (of the active path) to tune the tunable component (or its variable component) according to the tuning parameter.

8 illustrates that in some embodiments, some or all of the diversity receiver configurations (e.g., those shown in FIGS. 3, 4, 5, and 6) may be implemented in whole or in part, Lt; / RTI > Such a module may be, for example, a front-end module (FEM). Such a module may be, for example, a diversity receiver (DRx) FEM. In the example of FIG. 8, the module 800 may include a packaging substrate 802, and a plurality of components may be mounted on the packaging substrate 802. For example, a controller 804 (which may include a front-end power management integrated circuit [FE-PIMC]), a low noise amplifier assembly 806 (which may include one or more variable- gain amplifiers) A matching component 808 (which may include more than one fixed or tunable phase-shift component 831 and more than one fixed or tunable impedance matching component 832) (including a switching network 833 of SPST switches) ) And a filter bank 812 (which may include one or more bandpass filters) may be mounted and / or implemented on and / or on the packaging substrate 802 . Other components, such as multiple SMT devices 814, may also be mounted on the packaging substrate 802. While all of the various components are shown as being laid out on the packaging substrate 802, it will be understood that some component (s) may be implemented on other component (s).

In some implementations, devices and / or circuits having one or more of the features described herein may be included in an RF electronic device, such as a wireless device. Such devices and / or circuits may be implemented directly in a wireless device in a modular fashion as described herein, or in some combination thereof. In some embodiments, such a wireless device may include, for example, a cellular telephone, a smart phone, a handheld wireless device with or without telephone capability, a wireless tablet, and the like.

FIG. 9 illustrates an example wireless device 900 having one or more beneficial features described herein. In the context of one or more modules having one or more of the features described herein, such modules generally include a dashed box 901 (e.g., which may be implemented as a front-end module), a downstream module And a diversity receiver (DRx) module 800 (which may be implemented as a front-end module, for example).

9, power amplifiers (PAs) 920 receive their respective RF signals from a transceiver 910, which may be configured and operated in a known manner to generate RF signals to be amplified and transmitted , And can process the received signal. The transceiver 910 is shown to interact with a baseband subsystem 908 that is configured to provide a conversion between a suitable data and / or voice signal for the user and an RF signal suitable for the transceiver 910. The transceiver 910 may also communicate with a power management component 906 configured to manage power for operation of the wireless device 900. [ This power management may also control the operation of baseband subsystem 908 and modules 901, 911, and 800.

The baseband subsystem 908 is shown connected to the user interface 902 to enable various inputs and outputs of voice and / or data provided to or received from the user. The baseband subsystem 908 may also be connected to a memory 904 configured to store data and / or instructions that enable operation of the wireless device and / or provide a storage of information to a user.

In the example wireless device 900, the outputs of PAs 920 are shown to be matched (via respective matching circuits 922) and routed to their respective duplexers 924. These amplified and filtered signals may be routed to the primary antenna 916 via antenna switch 914 for transmission. In some embodiments, duplexer 924 may allow transmission and reception operations to be performed concurrently using a common antenna (e. G., Primary antenna 916). In FIG. 9, the received signal is shown to be routed to the "Rx" path, which may include, for example, a low-noise amplifier (LNA).

The wireless device also includes a diversity receiver module (800) that receives signals from a diversity antenna (926) and a diversity antenna (926). The diversity receiver module 800 processes the received signal and transmits it to the diversity RF module 911 which further processes the signal prior to feeding the processed signal to the transceiver 910 via a cable 935 do.

One or more features of the present disclosure may be implemented in the various cellular frequency bands described herein. Examples of these bands are listed in Table 1. It will be appreciated that at least some of the bands may be divided into sub-bands. It will also be appreciated that one or more features of the present disclosure may be implemented in a frequency range that does not have the same designation as the example of Table 1.

It is to be understood that the words "comprises", "including", etc., unless the context clearly dictates otherwise throughout the description and claims, should be interpreted as an inclusive meaning, not an exclusive or exhaustive sense do; That is, "including, but not limited to," The term "coupled" as used herein generally refers to two or more elements that can be directly connected or connected through one or more intermediate elements. In addition, the words "herein "," above ", "below ", and similar terms, when used in this application, refer to this application as a whole, rather than any particular portion of the present application. The words of the above description using singular or plural, as the context allows, may also include a plurality or a singular number, respectively. The word "or" when referring to a list of two or more items encompasses all of the following interpretations: any of the items in the list, all of the items in the list, and any combination of items in the list.

The above detailed description of embodiments of the present invention is not intended to be exhaustive or to limit the invention to the precise form disclosed above. Although specific embodiments and examples of the present invention have been described above for purposes of illustration, various equivalents of modifications are possible within the scope of the present invention, as ordinary skill in the pertinent art will recognize. For example, although processes or blocks are presented in a given order, alternative embodiments may use routines with steps in different orders or may use systems with blocks, 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, although processes or blocks are sometimes depicted as being performed continuously, these processes or blocks may instead be performed in parallel, or may be performed at different times.

The teachings of the present invention provided herein may not necessarily be applied to the systems described above but also to other systems. The elements and operations of the various embodiments described above may be combined to provide further embodiments.

While some embodiments of the present invention have been described, these embodiments are presented by way of example only, and are not intended to limit the scope of the present disclosure. Indeed, the novel methods and systems described herein may be implemented in various other forms; In addition, various omissions, substitutions and changes in the form of methods and systems described herein may be made without departing from the spirit of the disclosure. The appended claims and their equivalents are intended to cover such forms or modifications as fall within the scope and spirit of the present disclosure.

Claims (20)

A receiving system comprising:
A first amplifier, the first amplifier being arranged along a first path between an input of the receiving system and an output of the receiving system and being configured to amplify a signal received at the first amplifier;
A second amplifier, the second amplifier being arranged along a second path between the input of the receiving system and the output of the receiving system and configured to amplify the signal received at the second amplifier;
A single-pole / single-throw (SPST) switch disposed between the first path and the second path and configured to couple the first path and the second path; And
A controller configured to receive a band selection signal and enable one of the first amplifier or the second amplifier based on the band selection signal and to control the SPST switch,
≪ / RTI > The method of claim 1, wherein the controller is responsive to receiving a band selection signal representative of a single frequency band, enabling one of the first amplifier or the second amplifier corresponding to the single frequency band, To open the receiving system. 2. The apparatus of claim 1, wherein the controller is responsive to receiving a band selection signal representative of a plurality of frequency bands, wherein the controller enables one of the first amplifier or the second amplifier corresponding to one of the plurality of frequency bands And to close the SPST switch. 2. The method of claim 1, further comprising: a first phase-shift component, wherein the first phase-shift component is disposed along the first path and includes a second phase-shift component to increase the impedance for a frequency band corresponding to the second path, And to phase-shift the signal passing through the first phase-shift component. 5. The receiving system of claim 4, wherein the first phase-shift component is disposed between the SPST switch and an input of the receiving system. 5. The method of claim 4, wherein the first phase-shift component comprises a tunable phase-shift component, wherein the tunable phase-shift component comprises: Shifted by an amount controlled by a phase-shift tuning signal. 7. The receiving system of claim 6, wherein the controller is configured to generate the phase-shift tuning signal based on the band selection signal. 2. The system of claim 1, further comprising a first impedance matching component disposed along the first path and configured to reduce the noise figure of the first path. 9. The receiving system of claim 8, wherein the first impedance matching component is disposed between the SPST switch and the first amplifier. 9. The receiving system of claim 8, wherein the first impedance matching component comprises a tunable impedance matching component configured to indicate an impedance controlled by an impedance tuning signal received from the controller. 11. The receiving system of claim 10, wherein the controller is configured to generate the impedance tuning signal based on the band selection signal. 2. The method of claim 1, further comprising: receiving an input signal received at an input of the receiving system as a first signal in a first frequency band propagated along the first path and a second signal in a second frequency band propagated along the second path, RTI ID = 0.0 > 2 < / RTI > signals. The receiving system of claim 1, wherein at least one of the first amplifier or the second amplifier comprises a dual-stage amplifier. 2. The receiving system of claim 1, wherein the controller is further configured to disable the other of the first amplifier or the second amplifier. As a radio frequency (RF) module,
A packaging substrate configured to receive a plurality of components; And
A receiving system implemented on the packaging substrate
/ RTI >
The receiving system being arranged to amplify a signal received at the first amplifier, the first amplifier being disposed along a first path between an input of the RF module and an output of the RF module; A second amplifier, the second amplifier being disposed along a second path between an input of the RF module and an output of the RF module; A single-pole / single-throw switch disposed between the first path and the second path and configured to couple the first path and the second path; And a controller configured to receive the band selection signal and enable one of the first amplifier or the second amplifier based on the band selection signal, and to control the switch. 16. The radio frequency (RF) module of claim 15, wherein the RF module is a diversity receiver front-end module (FEM). 16. The receiver of claim 15, wherein the receiving system further comprises a first phase-shift component, wherein the first phase-shift component is arranged along the first path and has an impedance for a frequency band corresponding to the second path Shift component to phase-shift the signal passing through the first phase-shift component. A wireless device,
A first antenna configured to receive a first radio-frequency (RF) signal;
A first front end module (FEM) in communication with the first antenna, the first FEM including a packaging substrate configured to accommodate a plurality of components, the first FEM including a receiving system implemented on the packaging substrate Further includes -; And
A transceiver configured to receive a processed version of the first RF signal from an output of the first FEM over a cable and to generate data bits based on the processed version of the first RF signal;
Lt; / RTI >
The receiving system being arranged to amplify a signal received at the first amplifier, the first amplifier being disposed along a first path between an input of the first FEM and an output of the first FEM, the first amplifier having: A second amplifier, the second amplifier being arranged along a second path between the input of the first FEM and the output of the first FEM and configured to amplify the signal received at the second amplifier; A single-pole / single-throw switch disposed between the first path and the second path and configured to couple the first path and the second path; And a controller configured to receive a band selection signal and enable one of the first amplifier or the second amplifier based on the band selection signal, and to control the switch. 19. The apparatus of claim 18, further comprising: a second antenna configured to receive a second radio-frequency (RF) signal; and a second FEM in communication with the first antenna, Receive a processed version of the second RF signal and generate data bits based on the processed version of the second RF signal. 19. The system of claim 18, wherein the receiving system further comprises a first phase-shift component, wherein the first phase-shift component is arranged along the first path and has an impedance for a frequency band corresponding to the second path Shift component of the first phase-shift component to increase the phase-shift of the first phase-shift component.

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