Patent Publication Number: US-2023146310-A1

Title: Consolidated front-end architecture

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Patent Application No. 63/276,997, filed Nov. 8, 2021 and titled “CONSOLIDATED FRONT-END ARCHITECTURE,” which is herein incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     Field 
     Embodiments of the invention relate to electronic systems, and in particular, to radio frequency electronics. 
     Description of Related Technology 
     In wireless applications, wireless communication devices typically include components in a front-end module that are configured to condition (for instance, filter and/or amplify) received radio-frequency (RF) signals. The RF signals can be cellular signals, wireless local area network (WLAN) signals, or the like. The front-end module can be configured to direct these signals to appropriate antennas, filters, amplifiers, and/or downstream modules for processing. 
     Front-end modules can be used for transmitting and/or receiving signals of a wide range of frequencies. For example, a front-end modules can be used to wirelessly communicate RF signals in a frequency range of about 30 kHz to 300 GHz, such as in the range of about such as in the range of about 400 MHz to about 7.125 GHz for Frequency Range 1 (FR1) of the Fifth Generation (5G) communication standard or in the range of about 24.250 GHz to about 71.000 GHz for Frequency Range 2 (FR2) of the 5G communication standard. 
     Examples of RF communication systems with front-end modules include, but are not limited to, mobile phones, tablets, base stations, network access points, customer-premises equipment (CPE), laptops, and wearable electronics. 
     SUMMARY 
     According to one embodiment there is provided a radio-frequency front-end configuration having a shared amplifier network, the front-end configuration comprising a first signal path configured to provide a cellular radio-frequency signal, a second signal path configured to provide a Wi-Fi radio-frequency signal, and a shared amplifier network that forms at least part of the first signal path and the second signal path, the shared amplifier network comprising a low noise amplifier configured to amplify the cellular and the Wi-Fi radio-frequency signals provided by the respective signal path and a power amplifier configured to amplify the cellular and the Wi-Fi radio-frequency signals provided by the respective signal path to an antenna. 
     One example further comprises a multiplexer configured to provide the cellular radio-frequency signal from the antenna to the first signal path and configured to provide the Wi-Fi radio-frequency signal from the antenna to the second signal path. 
     Another example further comprises an antenna switch module for selecting between a first radio-frequency band of the cellular radio-frequency signal and a second radio-frequency band of the cellular radio-frequency signal. 
     In one example the first signal path includes a first band pass filter configured to pass cellular radio-frequency signals in a first radio-frequency band, and wherein the second signal path includes a second band pass filter configured to pass cellular radio-frequency signals in a second radio-frequency band. 
     In one example the cellular frequency range is separated from the Wi-Fi frequency range by a frequency gap that is smaller than or equal to approximately 15 MHz, 13 MHz or 3 MHz. 
     In one example the Wi-Fi radio-frequency signal includes a frequency band for WLAN communication having a frequency range of between 2403 MHz to 2483 MHz, 5150 MHz to 5850 MHz, or 5925 MHz to 7125 MHz. 
     In one example the cellular radio-frequency signal includes frequencies between 2300 MHz to 2400 MHz and between 2496 MHz to 2690 MHz and the Wi-Fi radio-frequency signal includes frequencies between 2403 MHz to 2483 MHz. 
     In one example the cellular radio-frequency signal includes frequencies between 4400 MHz to 5000 MHz and the Wi-Fi radio-frequency signal includes frequencies between 5150 MHz to 5850 MHz. 
     In one example the cellular radio-frequency signal includes frequencies between 5855 MHz to 5925 MHz and the Wi-Fi radio-frequency signal includes frequencies between 5925 MHz to 7125 MHz. 
     In one example the first signal path includes a first filter configured to pass frequencies between 2300 MHz to 2400 MHz and a second filter configured to pass frequencies between 2496 MHz to 2690 MHz. 
     Another example further comprises a transmit/receive select switch configured to select either the low noise amplifier or the power amplifier for amplifying the first radio-frequency signal or the second radio-frequency signal. 
     In one example the first radio-frequency signal is provided via a first signal port and the second radio-frequency signal is provided via a second signal port. 
     According to another embodiment there is provided a radio-frequency module comprising a packaging substrate configured to receive a plurality of components, and a semiconductor die implemented on the packaging substrate, the semiconductor die including a front-end configuration comprising a first signal path configured to provide a cellular radio-frequency signal, a second signal path configured to provide a Wi-Fi radio-frequency signal, and a shared amplifier network that forms at least part of the first signal path and the second signal path, the shared amplifier network comprising a low noise amplifier configured to amplify the cellular and the Wi-Fi radio-frequency signals provided by the respective signal path and a power amplifier configured to amplify the cellular and the Wi-Fi radio-frequency signals provided by the respective signal path to an antenna. 
     In one example the radio-frequency module is a diversity receiver front-end configuration or a multi-input multi-output module. 
     Another example further comprises a multiplexing assembly. 
     According to another embodiment there is provided a wireless device comprising an antenna port coupled to one or more antennas, an antenna switch module, a radio-frequency module, the radio-frequency module including a front-end configuration comprising a first signal path configured to provide a cellular radio-frequency signal, a second signal path configured to provide a Wi-Fi radio-frequency signal, and a shared amplifier network that forms at least part of the first signal path and the second signal path, the shared amplifier network comprising a low noise amplifier configured to amplify the cellular and the Wi-Fi radio-frequency signals provided by the respective signal path and a power amplifier configured to amplify the cellular and the Wi-Fi radio-frequency signals provided by the respective signal path to an antenna, and a controller configured to provide a control signal to the switching circuit. 
     One example further comprises a controller for controlling a transmit/receive select switch to thereby coordinate the transmission and reception of the cellular and Wi-Fi radio-frequency signals. 
     According to another embodiment there is provided a method of coordinating the transmission and reception of a cellular radio-frequency signal and a Wi-Fi radio-frequency signal, the method comprising providing a shared amplifier network that forms at least part of a first signal path for providing a cellular radio-frequency signal and a second signal path for providing a Wi-Fi radio-frequency signal, the shared amplifier network including a low noise amplifier and a power amplifier, and controlling, with a controller, the reception or transmission of the cellular radio-frequency signal with the reception or transmission of the Wi-Fi radio-frequency signal to thereby enable the amplification of one of the cellular or Wi-Fi radio-frequency signals with the low noise amplifier and the amplification of the other of the cellular or Wi-Fi radio-frequency signals with the power amplifier. 
     Still other aspects, embodiments, and advantages of these exemplary aspects and embodiments are discussed in detail below. Embodiments disclosed herein may be combined with other embodiments in any manner consistent with at least one of the principles disclosed herein, and references to “an embodiment,” “some embodiments,” “an alternate embodiment,” “various embodiments,” “one embodiment” or the like are not necessarily mutually exclusive and are intended to indicate that a particular feature, structure, or characteristic described may be included in at least one embodiment. The appearances of such terms herein are not necessarily all referring to the same embodiment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram of an example wireless device having a primary antenna and a diversity antenna. 
         FIG.  2    is a schematic diagram of an example front-end configuration. 
         FIG.  3    is a schematic diagram of another example front-end configuration. 
         FIG.  4    is a schematic diagram showing example frequency bands for use in wireless communications. 
         FIG.  5    is a schematic diagram of a front-end configuration according to one embodiment. 
         FIG.  6 A  is a schematic diagram of a front-end configuration according to another embodiment. 
         FIG.  6 B  is a schematic diagram of a front-end configuration according to another embodiment. 
         FIG.  7    is a schematic diagram of a diversity receive module according to one embodiment. 
         FIG.  8    is a schematic diagram of a wireless device that includes the example diversity receive module of  FIG.  7   . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The following detailed description of certain embodiments presents various descriptions of specific embodiments. However, the innovations described herein can be embodied in a multitude of different ways, for example, as defined and covered by the claims. In this description, reference is made to the drawings where like reference numerals can indicate identical or functionally similar elements. It will be understood that elements illustrated in the figures are not necessarily drawn to scale. Moreover, it will be understood that certain embodiments can include more elements than illustrated in a drawing and/or a subset of the elements illustrated in a drawing. Further, some embodiments can incorporate any suitable combination of features from two or more drawings. 
     Aspects and embodiments described herein are directed to a front-end configuration having consolidated radio frequency paths. This advantageously enables modules incorporating the front-end configuration to have a reduced printed circuit board (PCB) footprint, resulting in greater miniaturization and lower cost. 
     Typically, wireless communication frequencies can be divided into a low frequency band (e.g., approximately 698 MHz-approximately 960 MHz, LB), a middle frequency band (e.g., approximately 1427 MHz-approximately 2200 MHz, MB), a high frequency band (e.g., approximately 2300 MHz-approximately 2690 MHz, HB) and an ultrahigh frequency band (e.g., approximately 3400 MHz-approximately 3600 MHz, UHB). The frequency bands may be cellular frequency bands, such as UMTS (Universal Mobile Telecommunications System) frequency bands described below in Table 1, or other non-UMTS frequency bands. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                   
                 Tx Frequency 
                 Rx Frequency 
               
               
                   
                 Band 
                 Mode 
                 Range (MHz) 
                 Range (MHz) 
               
               
                   
                   
               
             
            
               
                   
                 B1 
                 FDD 
                 1,920-1,980 
                 2,110-2,170 
               
               
                   
                 B2 
                 FDD 
                 1,850-1,910 
                 1,930-1,990 
               
               
                   
                 B3 
                 FDD 
                 1,710-1,785 
                 1,805-1,880 
               
               
                   
                 B4 
                 FDD 
                 1,710-1,755 
                 2,110-2,155 
               
               
                   
                 B5 
                 FDD 
                 824-849 
                 869-894 
               
               
                   
                 B6 
                 FDD 
                 830-840 
                 875-885 
               
               
                   
                 B7 
                 FDD 
                 2,500-2,570 
                 2,620-2,690 
               
               
                   
                 B8 
                 FDD 
                 880-915 
                 925-960 
               
               
                   
                 B9 
                 FDD 
                 1,749.9-1,784.9 
                 1,844.9-1,879.9 
               
               
                   
                 B10 
                 FDD 
                 1,710-1,770 
                 2,110-2,170 
               
               
                   
                 B11 
                 FDD 
                 1,427.9-1,447.9 
                 1,475.9-1,495.9 
               
               
                   
                 B12 
                 FDD 
                 699-716 
                 729-746 
               
               
                   
                 B13 
                 FDD 
                 777-787 
                 746-756 
               
               
                   
                 B14 
                 FDD 
                 788-798 
                 758-768 
               
               
                   
                 B15 
                 FDD 
                 1,900-1,920 
                 2,600-2,620 
               
               
                   
                 B16 
                 FDD 
                 2,010-2,025 
                 2,585-2,600 
               
               
                   
                 B17 
                 FDD 
                 704-716 
                 734-746 
               
               
                   
                 B18 
                 FDD 
                 815-830 
                 860-875 
               
               
                   
                 B19 
                 FDD 
                 830-845 
                 875-890 
               
               
                   
                 B20 
                 FDD 
                 832-862 
                 791-821 
               
               
                   
                 B21 
                 FDD 
                 1,447.9-1,462.9 
                 1,495.9-1,510.9 
               
               
                   
                 B22 
                 FDD 
                 3,410-3,490 
                 3,510-3,590 
               
               
                   
                 B23 
                 FDD 
                 2,000-2,020 
                 2,180-2,200 
               
               
                   
                 B24 
                 FDD 
                 1,626.5-1,660.5 
                 1,525-1,559 
               
               
                   
                 B25 
                 FDD 
                 1,850-1,915 
                 1,930-1,995 
               
               
                   
                 B26 
                 FDD 
                 814-849 
                 859-894 
               
               
                   
                 B27 
                 FDD 
                 807-824 
                 852-869 
               
               
                   
                 B28 
                 FDD 
                 703-748 
                 758-803 
               
               
                   
                 B29 
                 FDD 
                 N/A 
                 716-728 
               
               
                   
                 B30 
                 FDD 
                 2,305-2,315 
                 2,350-2,360 
               
               
                   
                 B31 
                 FDD 
                 452.5-457.5 
                 462.5-467.5 
               
               
                   
                 B32 
                 FDD 
                 N/A 
                 1,452-1,496 
               
               
                   
                 B33 
                 TDD 
                 1,900-1,920 
                 1,900-1,920 
               
               
                   
                 B34 
                 TDD 
                 2,010-2,025 
                 2,010-2,025 
               
               
                   
                 B35 
                 TDD 
                 1,850-1,910 
                 1,850-1,910 
               
               
                   
                 B36 
                 TDD 
                 1,930-1,990 
                 1,930-1,990 
               
               
                   
                 B37 
                 TDD 
                 1,910-1,930 
                 1,910-1,930 
               
               
                   
                 B38 
                 TDD 
                 2,570-2,620 
                 2,570-2,620 
               
               
                   
                 B39 
                 TDD 
                 1,880-1,920 
                 1,880-1,920 
               
               
                   
                 B40 
                 TDD 
                 2,300-2,400 
                 2,300-2,400 
               
               
                   
                 B41 
                 TDD 
                 2,496-2,690 
                 2,496-2,690 
               
               
                   
                 B42 
                 TDD 
                 3,400-3,600 
                 3,400-3,600 
               
               
                   
                 B43 
                 TDD 
                 3,600-3,800 
                 3,600-3,800 
               
               
                   
                 B44 
                 TDD 
                 703-803 
                 703-803 
               
               
                   
                 B45 
                 TDD 
                 1,447-1,467 
                 1,447-1,467 
               
               
                   
                 B46 
                 TDD 
                 5,150-5,925 
                 5,150-5,925 
               
               
                   
                 B65 
                 FDD 
                 1,920-2,010 
                 2,110-2,200 
               
               
                   
                 B66 
                 FDD 
                 1,710-1,780 
                 2,110-2,200 
               
               
                   
                 B67 
                 FDD 
                 N/A 
                 738-758 
               
               
                   
                 B68 
                 FDD 
                 698-728 
                 753-783 
               
               
                   
                   
               
            
           
         
       
     
     The high frequency band includes, but is not limited to, Band 40 (B40), Band 30 (B30), Band 41 (B41) and Band 7 (B7), etc. B41 is used in time division duplexing (TDD) and thus has a single frequency band of approximately 2496 MHz to approximately 2690 MHz, which is utilized for both transmit (Tx) and receive (Rx) operations. Similarly, B40 is used in TDD and thus has a single frequency band of approximately 2300 MHz to approximately 2400 MHz. B41 and B40 can be utilized in cellular communications, e.g., 3rd generation partnership project (3GPP) wireless device. B7 is used in frequency division duplexing (FDD) and thus performs simultaneous Tx and Rx operations via different frequencies, for example, Tx (approximately 2500 MHz to approximately 2570 MHz) and Rx (approximately 2620 MHz to approximately 2690 MHz) paths. This is typically accomplished by the use of a duplexer, which combines the Tx and Rx paths into a common terminal, or signal port. B30 is also used in FDD and thus performs simultaneous Tx and Rx operations via different frequencies, for example, Tx (approximately 2305 MHz to approximately 2315 MHz) and Rx (approximately 2350 MHz to approximately 2360 MHz) paths. 
     The middle frequency band includes, but is not limited to, band 51 (B51) (e.g., approximately 1427 MHz-approximately 1432 MHz, TDD), band 74 (B74) (e.g., approximately 1427 MHz-approximately 1432 MHz and approximately 1475 MHz-approximately 1518 MHz, FDD), Band 65 (B65) (e.g., approximately 1920 MHz-approximately 2010 MHz and approximately 2110 MHz-approximately 2200 MHz, FDD) etc. The 2.4 GHz Wi-Fi band has a frequency range of approximately 2403 MHz to approximately 2483 (or approximately 2483.5) MHz, which lies between B40 and B41 and can be utilized in wireless local area network (WLAN). 
     Existing cellular front-end architecture designs are typically configured to maintain separate and independent radio frequency signal paths for each radio access technology (RAT) such as cellular and Wi-Fi. The reason for this is largely due to legacy implementations of transceivers and modems that need to be kept separate, which naturally led to the separation of cellular and Wi-Fi RATs in front-end modules. However, maintaining these two separate RF solutions in the front-end module results in a large printed circuit board (PCB) footprint and increased associated costs. 
     It would therefore be advantageous to be able to miniaturize front-end modules by consolidating aspects of the two RAT signal paths. However, in order to support both RATs the consolidated path must be capable of supporting, for example, the different waveforms, modulation orders, timing, gain flatness, and dynamic error vector magnitude (EVM) of each RAT. 
       FIG.  1    shows an example wireless device  100  having a primary antenna  130  and a diversity antenna  140 . The wireless device  100  includes an RF module  114  and a cellular transceiver  112  that may be controlled by a controller  120 . The RF module  114  may be referred to as a front-end module (FEM) due to the physical proximity between the primary antenna  130  and RF module  114  to reduce attenuation due to cable/line loss. The RF module  114  may perform processing on an RF receive signal received from the primary antenna  130  and/or and RF transmit signal from the cellular transceiver  112  for transmission via the primary antenna  130 . To that end, the RF module  114  may include filters, power amplifiers, band select switches, matching circuits, and/or other components, as further described below. 
     In some embodiments, the primary antenna  130  and/or diversity antenna 140 are configured to receive signals within cellular frequency bands and wireless local area network (WLAN), also referred to herein as Wi-Fi, frequency bands. In such embodiments, the wireless device  100  can include one or more frequency multiplexers, such as multiplexer  142  coupled to the diversity antenna  140  that is configured to separate the diversity signal into different frequency ranges. The multiplexer  142  can also be referred to herein as an antenna-plexer. The multiplexer can be configured to include a low pass filter structure that passes a frequency range that includes low band cellular frequencies, a bandpass filter structure that passes a frequency range that includes low band WLAN signals and mid-band and high-band cellular signals, and a high pass filter structure that passes a frequency range that includes high-band WLAN signals. The controller  120  can be configured to control the DRx FEM  150  to selectively direct signals to suitable signal paths. The wireless device  100  also includes the WLAN transceiver  160  for processing WLAN signals. 
     In the example shown in  FIG.  1   , the diversity antenna  140  is coupled to the cellular transceiver  112  by a transmission line  135 , such as a cable or a printed circuit board (PCB) trace. 
       FIG.  2    illustrates an example front-end configuration  210 , such as a front-end module (FEM), diversity receiver module (DRx), and/or multiple input multiple output (MiMo) module. The front-end configuration  210  includes an antenna  140  configured to receive a radio frequency signal, a multiplexer  211  that includes a switching network  215  and a filter assembly  213 , an amplifier assembly  214  and a controller  220  for controlling the amplifier assembly  214  and switching network  215 . The front-end configuration  210  may be implemented in a module with multiple paths corresponding to multiple frequency bands and/or different communication protocols. 
     As illustrated, the multiplexer  211  receives a signal at a signal port  216  and provides up to 3 signals at output ports  217   a,    217   b,  and  217   c.  The multiplexer  211  is configured to select one or more radio access networks for processing by forming selected signal paths through the switching network  215 , and directing signals to designated filters in filter assembly  213  and/or amplifiers in amplifier assembly  214  that are associated with a desired or targeted radio access network. Controller  220  selects the enabled paths through the multiplexer  211 . 
     A filter for an individual signal path through the filter assembly  213  can be designed to a pass a frequency band associated with a particular radio access network. The radio access networks can correspond to cellular frequency bands, examples of which are described in Table 1 above, and/or WLAN frequency bands. 
     The filter assembly  213  provides filtering for the respective signals provided by the switching network  215 . The filter assembly  213  includes at least one filter per signal path through the filter assembly  213  that are disposed along a corresponding one of the plurality of signal paths and configured to act as a bandpass filter for a respective frequency band of the path. For example, a first filter may be configured to filter signals corresponding to the first radio access network, corresponding to a frequency band of a cellular communication standard, while a second filter may be configured to filter signals corresponding to the second radio access network, corresponding to a frequency band of a WLAN communication standard. 
     The amplifier assembly  214  provides amplification for one or more signals that pass through the assembly. The amplifier assembly  214  includes amplifiers disposed along a corresponding one of the signal paths through the multiplexer, with the amplifiers being configured to amplify a signal received at the amplifier assembly  214 . The amplifier assembly  214  and switching network  215  are controllable by the controller  220 . For example, in some implementations, each of the amplifiers in the amplifier assembly  214  includes an enable/disable input and is enabled (or disabled) based on an amplifier enable signal received and the enable/disable input. In some implementations, the amplifier enable signal may be transmitted by the controller  220 . 
       FIG.  3    shows an example front-end configuration  300  that includes an antenna  140 , multiplexer  311 , a cellular module  320 , and a Wi-Fi module  330 . In the example shown in  FIG.  3   , the multiplexer is configured to provide signals in a first frequency range to the cellular module  320  and to provide signals in a second frequency range to the Wi-Fi module  330 . In one example, the multiplexer  311  provides high band TDD cellular RF signals to the cellular module  320  and 2.4 GHz Wi-Fi signals to the Wi-Fi module  330 . As shown in  FIG.  3   , the multiplexer  311  supports a shared single feed from antenna  140 , and the separation of RF signals according to each RAT is achieved by filtering and/or splitting the RF signals by frequency with low loss. 
     The cellular module  320  comprises a band select switch  321 , a first high band filter  322 , a second high band filter  323 , a transmit/receive (Rx/Tx) select switch  324 , a first amplifier  325  (power amplifier), a second amplifier  326  (low noise amplifier), an RF transmit port  327  and an RF receive port  328 . In certain implementations, the first high band filter  322  is configured to pass RF band B40 signals such that selecting the first high band filter  322  with the band select switch  321  enables transmission or reception of B40 signals, while a second high band filter  323  is configured to pass RF band B41 signals such that selecting the second high band filter  323  with the band select switch  321  enables transmission or reception of B41 signals. 
     As discussed above, B40 and B41 are commonly used high frequency bands that coexist very close to the 2.4 GHz Wi-Fi band frequency range.  FIG.  4    illustrates the relative separation between the 2.4 GHz Wi-Fi band and the conventional B40 and B41 bands. As shown in  FIG.  4   , the 2.4 GHz Wi-Fi band has a frequency range of 2403 MHz to 2483 MHz, band B40 has a frequency range of 2300 MHz to 2400 MHz, and B41 has a frequency range of 2496 MHz to 2690 MHz. The gap between a lower channel of the Wi-Fi band and an upper channel of Band B40 is 3 MHz, and a gap between an upper channel of the Wi-Fi band and a lower channel of Band B41 is 13 MHz. As shown in  FIG.  4   , using a band configuration of B40 and B41 with the 2.4 GHz Wi-Fi band results in a relatively small frequency offset gap of 3 MHz and 13 MHz respectively. 
     It will be appreciated that although the specific examples described herein relate to enabling the consolidation of signal paths for 2.4 GHz Wi-Fi signals and adjacent frequency bands B40 and B41, features of the disclosure are not limited to such examples and may be applied to other Wi-Fi signals and their corresponding adjacent frequency bands. For example, similar principles may be applied when using the 5 GHz Wi-Fi band (ranging from approximately 5.15 GHz to approximately 5.85 GHz) and adjacent frequency band n79 (approximately 4.4 GHz to approximately 5.00 GHz), where the 5 GHz Wi-Fi band is separated from the n79 band by a frequency gap of approximately 15 MHz, or when using the 6 GHz Wi-Fi band (approximately 5.925 GHz to approximately 7.125 GHz) and adjacent frequency band B47 (approximately 5.855 GHz to 5.925 GHz), where there is effectively no frequency gap between the 6 GHz Wi-Fi band and the B47 band. 
     The Wi-Fi module  330  of  FIG.  3    comprises an Rx/Tx select switch  331  (also referred to as a transmit/receive switch), a first amplifier  332  configured to amplify WLAN signals for transmission (e.g., a power amplifier or PA), a second amplifier  333  configured to amplify received WLAN signals (e.g., a low-noise amplifier or LNA). The Wi-Fi module  330  further comprises a WLAN transmit port  334  configured to receive signals for transmission using antenna  140 , and a WLAN receive port  335  configured to receive signals that have been received via antenna  140 . Accordingly, the front-end configuration  300  can be configured to multiplex multiple cellular signals, extract received WLAN signals, and process WLAN signals for transmission. In some embodiments, the front-end configuration  710  is configured to support simultaneous processing of multiple mid-band and/or high-band cellular frequency bands in conjunction with filtering the WLAN signals. 
     Thus, the solutions described above employ separate, dedicated paths that are implemented for each RAT through the use of separate hardware in the same front-end architecture to provide bi-directional communication of cellular signals for two separate frequency bands and bi-directional communication of Wi-Fi signals. 
       FIG.  5    shows a front-end configuration  500  that addresses the above problems by consolidating RF signal paths to provide a combined cellular/Wi-Fi module. The example front-end configuration  500  of  FIG.  5    includes an antenna  140 , multiplexer  511 , and a combined cellular/Wi-Fi module  520 . In the example shown in  FIG.  5   , the multiplexer  511  is configured to provide signals in a first frequency range to a first port  512  of the cellular/Wi-Fi module  520  and to provide signals in a second frequency range to a second port  513  of the cellular/Wi-Fi module  520 . 
     The cellular/Wi-Fi module  520  includes an antenna switch module (ASM)  521  (also referred to herein as an antenna switch), a first high band filter  522 , a second high band filter  523 , a transmit/receive (Rx/Tx) select switch  524 , a shared amplifier network comprising a first amplifier  525  (power amplifier), a second amplifier  526  (low noise amplifier), a transmit port  527 , and a receive port  528 . 
     The ASM  521  is configured to select between a first high frequency RF signal band and a second high frequency RF signal band. In certain implementations, a first high band filter  322  is configured to pass RF cellular band B40 signals such that selecting high band filter  322  with the band select switch  321  enables B40 signals to pass through the first signal path, while a second high band filter  323  is configured to pass RF cellular band B41 signals such that selecting high band filter  323  with the band select switch  321  enables B41 signals to pass through the first signal path. 
     The first amplifier  525  is configured as a power amplifier for amplifying transmission signals that are received from transmission port  527  and provided to the antenna  140 , and the second amplifier  526  is configured as an LNA for amplifying received signals from antenna  140  that are provided from the antenna  140  to the receive port  528 . 
     Accordingly, front-end configuration  500  uses circuit components of existing cellular RF paths in a typical smartphone architecture developed for TDD high frequency bands (such as bands B40 and B41) to process Wi-Fi signals (such as 2.4 GHz Wi-Fi signals). In particular, the amplifiers of the high frequency band TDD cellular path are configured to meet the power levels, linearity, dynamic and timing specs required to process the Wi-Fi signal. In certain implementations, the TDD high frequency bands cover frequency ranges that are substantially the same as, at least partially overlap with, or have a relatively small frequency offset gap with the Wi-Fi carrier frequency range. For example, the cellular frequency range may be separated from the Wi-Fi frequency range by a frequency gap that is smaller than or equal to approximately 15 MHz, 13 MHz or 3 MHz. 
     Power amplifier  525  is therefore configured for use with both cellular and Wi-Fi signals when the front-end configuration  500  is in transmit mode. Similarly, LNA  526  is reused when the front-end configuration  500  is in receive mode. In re-using existing components of the cellular RF path hardware, the dedicated Wi-Fi module  330  may be eliminated to provide savings on cost and PCB footprint area. 
     A separate output on the band select switch  524  enables the Wi-Fi path to be routed to the second port  513  of the cellular/Wi-Fi module  520 , which is configured to act as a separate, dedicated output pin for Wi-Fi signals. The Wi-Fi signals may then be connected to the antenna multiplexer  511  in a similar manner as described above for  FIG.  3   . 
     Although front-end configuration  500  is able to facilitate a reduced PCB footprint area, front-end configuration  500  may be unable to provide uncoordinated simultaneous independent use of both the HB TDD cellular RF path and Wi-Fi RF path at the same time. This usually occurs for the specific instance where a user is placing a voice call and simultaneously accessing data through a Wi-Fi link. In such instances, it is not possible to coordinate the transmission and reception of the cellular and Wi-Fi signals as the cellular base-station and Wi-Fi router operate independently. Therefore, the base-station and Wi-Fi router each act as the master of their respective RAT to determine the separate, and uncoordinated, timing of the transmit and receive signals for each RAT. In such instances where each RAT is uncoordinated, the consolidation of the RF paths in front-end configuration  500  results in one of the signals being prioritized for transmission/reception to at least maintain its communication link while the other signal is blocked, or “blanked”, and so suffers from data drop. 
     However, there are several important instances where a mobile device is able to coordinate the transmission and reception of cellular and Wi-Fi signals. These instances involve the mobile device acting as a Wi-Fi router for other peripheral devices, whereby the mobile device is able to coordinate the timing of its operation as a Wi-Fi router with the timing of cellular transmit/receive signals. In other words, the mobile device is able to control the transmission and reception of cellular and Wi-Fi signals to prevent a cellular signal and a Wi-Fi signal from being transmitted simultaneously and/or to prevent a cellular signal and a Wi-Fi signal from being received simultaneously. Thus, the mobile device prevents both the cellular and Wi-Fi signals from being provided simultaneously to either the low noise amplifier or the power amplifier. Important examples of when a mobile device acts as a Wi-Fi router include “screen mirroring” or content casting, where content is transmitted from the mobile device to a remote display, and when a mobile device acts as a local “Wi-Fi hotspot” for surrounding mobile devices by enabling the sharing of cellular data via a Wi-Fi connection. In these instances, the front-end configuration  500  would still be able to support both RATs at reduced cost and with reduced PCB footprint, provided the transmission and reception of each RAT is coordinated to avoid signal conflict on the shared components or common transmit/receive paths. 
     It will be appreciated that the front-end configuration  500  shown in  FIG.  5    is merely one example of implemented front-end implemented in accordance with the teachings herein.  FIG.  6 A  shows a second example front-end configuration that provides a combined cellular/Wi-Fi module having consolidated RF signal paths. 
     The example front-end configuration includes an antenna  140 , and a combined cellular/Wi-Fi module  620 . The front-end configuration provides a common RF receive path, whereby the separate RF signals are separated according to their respective frequencies within the consolidated cellular/Wi-Fi module  620 . 
     In the example shown in  FIG.  6 A , received signals are provided from the antenna  140  to a shared port  610  of the cellular/Wi-Fi module  620 . The cellular/Wi-Fi module  620  comprises a first band pass filter  621 , a second band pass filter  622 , a third band pass filter  623 , a transmit/receive (Rx/Tx) select switch  624 , a shared amplifier network including a first amplifier  625  (power amplifier), a second amplifier  626  (low noise amplifier), a transmit port  631  and a receive port  632 . 
     The first band pass filter  621  is configured to pass signals having a first frequency range, for example RF cellular band B40 signals, via a first signal path. The second band pass filter  622  is configured to pass signals having a second frequency range, for example RF cellular band B41 signals, via a second signal path. The third band pass filter  623  is configured to pass signals having a third frequency range, for example 2.4 GHz (Channel 1) Wi-Fi signals, via a third signal path. Once each of the signals has been separated, further circuitry (not shown) may provide signal conditioning and demodulation for the separate cellular and Wi-Fi signals. 
     As described above for  FIG.  5   , the first amplifier  625  is configured as a power amplifier for amplifying transmission signals that are received from transmission port  631 , and the second amplifier  626  is configured as an LNA for amplifying signals received from shared port  632 . 
     It will be appreciated that the front-ends herein are not limited to the use of three signal paths as shown in  FIG.  6 A  and that more, or fewer, signal paths may be provided. 
       FIG.  6 B  is a schematic diagram of a front-end configuration according to another embodiment. The example front-end configuration includes an antenna  140  and a combined cellular/Wi-Fi module  620 ′. 
     The cellular/Wi-Fi module  620 ′ includes a first high band transmit filter  621   a  (for example, B40 TX), a second high band transmit filter  622   a  (for example, 2.4 GHz WiFi Tx), a third high band transmit filter  623   a  (for example, B41 TX), a first high band receive filter  621   b  (for example, B40 RX), a second high band receive filter  622   b  (for example, 2.4 GHz WiFi RX), a third high band receive filter  622   c  (for example, B41 RX), a power amplifier  625 , a first LNA  626   a,  a second LNA  626   b,  a third LNA  626   c,  a transmit band selection switch  627 , an antenna switch  628 , a shared antenna port  610 , an RF transmit port  631 , a first RF receive port  632   a,  a second RF receive port  632   b,  and a third RF receive port  632   c.    
     In the example shown in  FIG.  6 B , received signals are provided from the antenna  140  to the shared antenna port  610  of the cellular/Wi-Fi module  620 ′. Thereafter, multi-on switch combining (for example, using the antenna switch  628  capable of connected to one of the Tx filters as well as one of the Rx filters) of the Tx and Rx filters for each frequency band enables TDD operation within a given band. 
     Accordingly, in comparison to  FIG.  6 A , the embodiment of  FIG.  6 B  replaces common shared Tx and Rx filters with separate Tx and Rx filters to enable better isolation. For example, isolation can be enhanced for Tx and Rx between the aggressor and victim bands. 
     Moreover, switch combining of these Tx and Rx filters with the other bands can be performed as Tx and Rx communications are switched back and forth in accordance with TDD operations. 
     Thus, operation can be considered as asynchronous and utilizes very high isolation between Tx and Rx of different frequency bands. The splitting of Tx and Rx filters relaxes the switch isolation specifications relative to a configuration in which the transmit and receive signals flow through common Tx and Rx filters. 
     Although shown as including three separate LNAs, in other implementations a broadband switch for the Rx/LNA paths followed by a single broadband LNA can be used instead of the dedicated three LNAs. 
       FIG.  7    shows that in some embodiments, the front-end configurations described above can be implemented, wholly or partially, in a module. Such a module can be, for example, a front-end module (FEM). Such a module can be, for example, a diversity receiver (DRx) FEM. Such a module can be, for example, a multi-input, multi-output (MiMo) module. 
     In the example of  FIG.  7   , a module  750  can include a packaging substrate  702 , and a number of components can be mounted on such a packaging substrate  702 . For example, a controller  720  (which may include a front-end power management integrated circuit [FE-PIMC]), an amplifier assembly  706  having one or more features as described herein (e.g., power amplifiers, low noise amplifiers, etc.), a multiplexing assembly  710  that includes a reconfigurable multiplexer  711 , and a filter bank  708 , which may include one or more bandpass filters, can be mounted and/or implemented on and/or within the packaging substrate  702 . In some embodiments, the filter bank  708  is implemented as part of the multiplexing assembly  710 . Other components, such as a number of surface-mount technology (SMT) devices  705 , can also be mounted on the packaging substrate  702 . Although all of the various components are depicted as being laid out on the packaging substrate  702 , it will be understood that some component(s) can be implemented over other component(s). 
       FIG.  8    is an exemplary block diagram illustrating a simplified wireless device  800  that includes a combined cellular/Wi-Fi module  500 ,  600  configured to switch and condition/filter the RF transmit signal and the RF receive signal in order to implement selected frequency band configuration. 
     The wireless device  800  includes a speaker  802 , a display  804 , a keyboard  806 , and a microphone  808 , all connected to a baseband subsystem  810 . A power source  842 , which may be a direct current (DC) battery or other power source, is also connected to the baseband subsystem  810  to provide power to the wireless device  800 . In a particular embodiment, the wireless device  800  can be, for example but not limited to, a portable telecommunication device such as a mobile cellular-type telephone. The speaker  802  and the display  804  receive signals from baseband subsystem  810 , as known to those skilled in the art. Similarly, the keyboard  806  and the microphone  808  supply signals to the baseband subsystem  810 . The baseband subsystem  810  includes a microprocessor (μP)  820 , memory  822 , analog circuitry  824 , and a digital signal processor (DSP)  826  in communication via bus  828 . Bus  828 , although shown as a single bus, may be implemented using multiple busses connected as necessary among the subsystems within the baseband subsystem  810 . The baseband subsystem  810  may also include one or more of an application specific integrated circuit (ASIC)  832  and a field programmable gate array (FPGA)  830 . 
     The microprocessor  820  and memory  822  provide the signal timing, processing, and storage functions for wireless device  800 . The analog circuitry  824  provides the analog processing functions for the signals within baseband subsystem  810 . The baseband subsystem  810  provides control signals to a transmitter  850 , a receiver  870 , a power amplifier  880 , and a switching module  890 , for example. 
     It should be noted that, for simplicity, only the basic components of the wireless device  800  are illustrated herein. The control signals provided by the baseband subsystem  810  control the various components within the wireless device  800 . Further, the function of the transmitter  850  and the receiver  870  may be integrated into a transceiver. 
     The baseband subsystem  810  also includes an analog-to-digital converter (ADC)  834  and digital-to-analog converters (DACs)  836  and  838 . In this example, the DAC  836  generates in-phase (I) and quadrature-phase (Q) signals  840  that are applied to a modulator  852 . The ADC  834 , the DAC  836 , and the DAC  838  also communicate with the microprocessor  820 , the memory  822 , the analog circuitry  824 , and the DSP  826  via bus  828 . The DAC  836  converts the digital communication information within baseband subsystem  810  into an analog signal for transmission to the modulator  852  via connection  840 . Connection  840 , while shown as two directed arrows, includes the information that is to be transmitted by the transmitter  850  after conversion from the digital domain to the analog domain. 
     The transmitter  850  includes the modulator  852 , which modulates the analog information on connection  840  and provides a modulated signal to upconverter  854 . The upconverter  854  transforms the modulated signal to an appropriate transmit frequency and provides the upconverted signal to the power amplifier  880 . The power amplifier  880  amplifies the signal to an appropriate power level for the system in which the wireless device  800  is designed to operate. 
     Details of the modulator  852  and the upconverter  854  have been omitted, as they will be understood by those skilled in the art. For example, the data on connection  840  is generally formatted by the baseband subsystem  810  into in-phase (I) and quadrature (Q) components. The I and Q components may take different forms and be formatted differently depending upon the communication standard being employed. 
     The power amplifier  880  supplies the amplified signal to a front-end module  862 , where the amplified signal may be conditioned and filtered by one or more signal conditioning filters for transmission. In an embodiment, the PA circuitry  808  comprises the power amplifier  880 . The RF transmit signal is supplied from the front-end module  862  to the antenna  860 . In an embodiment, the antenna  860  comprises an FDD/TDD antenna. 
     In an embodiment, the front-end module  862  comprises some or all of the front-end configurations  500 ,  600  described above. In an embodiment, switching module  890  comprises an RF module including a packaging substrate  702  and semiconductor die. 
     A signal received by antenna  860  will be directed from the front-end module  862  to the receiver  870 . The receiver  870  includes low noise amplifier circuitry  872 , a downconverter  874 , a filter  876 , and a demodulator  878 . 
     If implemented using a direct conversion receiver (DCR), the downconverter  874  converts the amplified received signal from an RF level to a baseband level (DC), or a near-baseband level (approximately 100 kHz). Alternatively, the amplified received RF signal may be downconverted to an intermediate frequency (IF) signal, depending on the application. The downconverted signal is sent to the filter  876 . The filter  876  comprises a least one filter stage to filter the received downconverted signal as known in the art. 
     The filtered signal is sent from the filter  876  to the demodulator  878 . The demodulator  878  recovers the transmitted analog information and supplies a signal representing this information via connection  886  to the ADC  834 . The ADC  834  converts these analog signals to a digital signal at baseband frequency and transfers the signal via bus  828  to the DSP  826  for further processing. 
     Having described above several aspects of at least one embodiment, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure and are intended to be within the scope of the invention. Accordingly, the foregoing description and drawings are by way of example only, and the scope of the invention should be determined from proper construction of the appended claims, and their equivalents. 
     It is to be appreciated that embodiments of the methods and apparatuses discussed herein are not limited in application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The above detailed description of certain embodiments is not intended to be exhaustive or to limit the invention to the precise form disclosed above. The methods and apparatuses are capable of implementation in other embodiments and of being practiced or of being carried out in various ways. Accordingly, the examples of specific implementations provided herein are for illustrative purposes only and are not intended to be limiting. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those ordinary skilled in the relevant art will recognize in view of the disclosure herein. 
     Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” The words “coupled” or “connected”, as generally used herein, refer to two or more elements that may be either directly connected, or connected by way of one or more intermediate elements. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list. 
     Moreover, conditional language used herein, such as, among others, “can,” “could,” “might,” “may,” “e.g.,” “for example,” “such as” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or states. Thus, such conditional language is not generally intended to imply that features, elements and/or states are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without author input or prompting, whether these features, elements and/or states are included or are to be performed in any particular embodiment. 
     The teachings of the invention provided herein can be applied to other systems, not necessarily the systems described above. The elements and acts of the various embodiments described above can be combined to provide further embodiments. 
     Some of the embodiments described above have provided examples in connection with mobile devices. However, the principles and advantages of the embodiments can be used for any other systems or apparatus that have needs for power amplifiers with power detection and clamping. Examples of such RF communication systems include, but are not limited to, mobile phones, tablets, base stations, network access points, customer-premises equipment (CPE), laptops, and wearable electronics. 
     While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure.