Patent Publication Number: US-11664963-B2

Title: Devices and methods related to radio-frequency front-end architecture for carrier aggregation of cellular bands

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation of U.S. patent application Ser. No. 16/598,847, filed Oct. 10, 2019, entitled “RADIO-FREQUENCY FRONT-END ARCHITECTURE FOR CARRIER AGGREGATION OF CELLULAR BANDS,” which is a continuation of U.S. patent application Ser. No. 14/824,161, filed Aug. 12, 2015, entitled “RADIO-FREQUENCY FRONT-END ARCHITECTURE FOR CARRIER AGGREGATION OF CELLULAR BANDS,” now U.S. Pat. No. 10,447,458, issued Oct. 15, 2019, which claims priority to U.S. Provisional Application No. 62/036,844, filed Aug. 13, 2014, entitled “RADIO-FREQUENCY FRONT-END ARCHITECTURE FOR CARRIER AGGREGATION OF CELLULAR BANDS,” the disclosure of each of which is hereby expressly incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Field 
     The present disclosure relates to carrier aggregation in radio-frequency applications. 
     Description of the Related Art 
     In some radio-frequency (RF) applications, cellular carrier aggregation (CA) can involve two or more RF signals being processed through a common path. For example, carrier aggregation can involve use of a path for a plurality of bands having frequency ranges that are sufficiently separated. In such a configuration, simultaneous operation of more than one band can be achieved. 
     SUMMARY 
     In accordance with a number of implementations, the present disclosure relates to a carrier aggregation (CA) architecture that includes a duplexer configured to provide duplexing functionality for a first frequency band and a second frequency band with a common antenna. The CA architecture further includes an a first amplification path and a second amplification path coupled to respective ports of the duplexer, each of the first amplification path and the second amplification path configured to amplify a signal in its respective frequency band, each amplification path including a transmit/receive (TX/RX) switch configured to provide time-division duplexing (TDD) functionality for the amplified signal and a received signal. 
     In some implementations, the first frequency band includes a B39 band. 
     In some implementations, the second frequency band includes a B41 band. 
     In some implementations, the CA architecture further includes an antenna switch module coupled to a node of the duplexer. 
     In some implementations, each of the first amplification path and the second amplification path include a band-selection switch. 
     In some implementations, the first amplification path includes a controller configured to provide one or more control functionalities for the operation of the first amplification path. 
     In some implementations, the first amplification path includes a power amplifier and a bias port configured to bias the power amplifier. 
     In some implementations, the TX/RX switch includes a common node coupled to the duplexer for TX and RX signals. 
     In some implementations, the present disclosure relates to a radio-frequency (RF) module that includes a packaging substrate configured to receive a plurality of components. The RF module further includes a carrier aggregation (CA) architecture implemented on the packaging substrate, the CA architecture including a duplexer configured to provide duplexing functionality for a first frequency band and a second frequency band with a common antenna, the CA architecture further including a first amplification path and a second amplification path coupled to respective ports of the duplexer, each of the first amplification path and the second amplification path configured to amplify a signal in its respective frequency band, each amplification path including a transmit/receive (TX/RX) switch configured to provide time-division duplexing (TDD) functionality for the amplified signal and a received signal. 
     In some implementations, the RF module is a power amplifier (PA) module. 
     In some implementations, the RF module is a front-end module (FEM). 
     In some implementations, the first frequency band includes a B39 band and the second frequency band includes a B41 band. 
     In some implementations, the CA architecture further includes an antenna switch module coupled to a node of the duplexer. 
     In some implementations, each of the first amplification path and the second amplification path include a band-selection switch. 
     In some implementations, the first amplification path includes a controller configured to provide one or more control functionalities for the operation of the first amplification path. 
     In some implementations, the first amplification path includes a power amplifier and a bias port configured to bias the power amplifier. 
     In some implementations, the TX/RX switch includes a common node coupled to the duplexer for TX and RX signals. 
     According to some teachings, the present disclosure relates to a radio-frequency (RF) device that includes a transceiver configured to process RF signals. The RF device further includes an RF module in communication with the transceiver, the RF module having a carrier aggregation (CA) architecture, the CA architecture including a duplexer configured to provide duplexing functionality for a first frequency band and a second frequency band with a common antenna, the CA architecture further including a first amplification path and a second amplification path coupled to respective ports of the duplexer, each of the first amplification path and the second amplification path configured to amplify a signal in its respective frequency band, each amplification path including a transmit/receive (TX/RX) switch configured to provide time-division duplexing (TDD) functionality for the amplified signal and a received signal. 
     In some implementations, the RF device includes a wireless device. 
     In some implementations, the wireless device is a cellular phone. 
     In some implementations, the first frequency band includes a B39 band and the second frequency band includes a B41 band. 
     In some implementations, the CA architecture further includes an antenna switch module coupled to a node of the duplexer. 
     In some implementations, each of the first amplification path and the second amplification path include a band-selection switch. 
     In some implementations, the first amplification path includes a controller configured to provide one or more control functionalities for the operation of the first amplification path. 
     In some implementations, the first amplification path includes a power amplifier and a bias port configured to bias the power amplifier. 
     In some implementations, the TX/RX switch includes a common node coupled to the duplexer for TX and RX signals. 
     For purposes of summarizing the disclosure, certain aspects, advantages and novel features of the inventions have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the present disclosure can be understood in greater detail, a more particular description may be had by reference to the features of various implementations, some of which are illustrated in the appended drawings. The appended drawings, however, merely illustrate the more pertinent features of the present disclosure and are therefore not to be considered limiting, for the description may admit to other effective features. 
         FIG.  1    is a schematic diagram of an example front-end architecture according to some implementations. 
         FIG.  2    is a schematic diagram of another example front-end architecture according to some implementations. 
         FIG.  3    is a schematic diagram of yet another example front-end architecture according to some implementations. 
         FIG.  4    is a schematic diagram of yet another example front-end architecture according to some implementations. 
         FIG.  5    is a schematic diagram of an example radio-frequency (RF) module including a front-end architecture according to some implementations. 
         FIG.  6    is a schematic diagram of an example RF device including a front-end architecture according to some implementations. 
     
    
    
     In accordance with common practice the various features illustrated in the drawings may not be drawn to scale. Accordingly, the dimensions of the various features may be arbitrarily expanded or reduced for clarity. In addition, some of the drawings may not depict all of the components of a given system, method or device. Finally, like reference numerals may be used to denote like features throughout the specification and figures. 
     DETAILED DESCRIPTION OF SOME IMPLEMENTATIONS 
     The headings provided herein, if any, are for convenience only and do not necessarily affect the scope or meaning of the claimed invention. 
     Cellular carrier aggregation (CA) can be supported by allowing two or more radio-frequency (RF) signals to be processed through a common path. For example, carrier aggregation can involve use of a path for a plurality of bands having frequency ranges that are sufficiently separated. In such a configuration, simultaneous operation of more than one band is possible. 
     In some implementations, the present disclosure relates to a front-end architecture that can be configured to support CA of two or more cellular bands. Various examples are described herein in the context of cellular bands B39 and B41 (e.g., as allocated for China Mobile network); however, it will be understood that one or more features of the present disclosure can also be implemented with other bands. 
     In some implementations, a front-end architecture having CA capability for the example bands of B39 having a frequency range of 1.880 to 1.920 GHz and B41 having a frequency range of 2.496 to 2.690 GHz can be implemented with a reduced component count, lower bill-of-materials (BoM) cost, and/or better RF performance. In some implementations, such an architecture can also be configured to support some or all of other carrier aggregation scenarios defined for a given mobile network. 
     In some implementations, CA is an evolution of the Long-Term Evolution (LTE) technology to increase data throughput. By aggregating two available spectra at the same or different frequency bands, the combined signal bandwidth can expand to allow transferring of more data at the same time. In one or more mobile networks, TD-LTE has been adopted as a 4G standard, and bands B39, B40 and B41 have been allocated. 
     In the example context of carrier aggregation of B39 band having a frequency range of 1.880 to 1.920 GHz and the B41 band having a frequency range of 2.496 to 2.690 GHz, technical challenges can arise. For example, due to the timing synchronization difficulty from two different towers to the handset and dynamically UL/DL (uplink/downlink) configuration adjustment being allowed, the transmit slot of one band could overlap in time with receive slot of the other band. In order to transmit and receive the signal from two bands at the same time, conventional architecture is to use two separate antennas for B39 and B41. Such a conventional architecture typically suffers from higher BoM costs and longer calibration procedures. 
     As described herein, one or more features of the present disclosure can provide a front-end architecture having a B39 TX/RX switch design to enable a single antenna design, as well as eliminating the need for a B39 RX filter. Such a front-end architecture can be implemented with a lower BoM cost and better performance. 
       FIG.  1    shows an example of a front-end architecture  100  configured to operate with two antennas  118 ,  130  for the example bands B39 and B41 according to some implementations. More particularly, a power amplifier (PA) path  120  is shown to be configured to provide B39 TX operation, where an input signal to be amplified is provided at an input node  122 . A PA  124  (e.g., associated with a high-band (HB) 4G signal) can amplify such an input signal, and the amplified signal is shown be provided to a band-selection switch  126  (e.g., a single-pull four-throw (SP4T) switch) configured to allow B39 TX operation. A B39 TX filter  127  is shown to be provided between the band-selection switch  126  and an antenna switch module (ASM)  128 . When the ASM  128  is operated in the B39 TX mode, the amplified and filtered RF signal can be routed to the antenna  130  for transmission. When the ASM  128  is operated in the B39 RX mode, a signal received through the antenna  130  can be routed to, for example, a low-noise amplifier (LNA) through a B39 RX filter  129 . 
     A PA path  102  is shown to be configured to facilitate B41 TX and B41 RX operations. An input signal to be amplified is provided at an input node  104 . A PA  106  can amplify such an input signal, and the amplified signal is shown be provided to a band/mode selection switch  108  configured to allow B41 TX/RX operations. A B41 TX filter  115  is shown to be provided between the band/mode selection switch  108  and an antenna switch module (ASM)  116 . When the ASM  116  is operated in the B41 band, the amplified and filtered RF signal can be routed to the antenna  118  for transmission. When in the B41 TX mode, the band/mode selection switch  108  is shown to route the amplified signal to the B41 TX filter. When in the B41 RX mode, a signal received through the antenna  118  can be routed to the band/mode selection switch  108  through the ASM  116 . The band/mode selection switch  108  can then route the received signal to, for example, a low-noise amplifier (LNA) through a B41 RX node. 
     In the example of  FIG.  1   , a controller  110  is shown to provide one or more control functionalities for the operation of the B41 amplification path  102 . Further, the PA  106  is shown to be biased through a bias node  112 . Such control and biasing functionalities can also be provided for the B39 amplification path  120 . In some implementations, the foregoing example of a two-antenna system for B39 and B41 bands can be bulky and have relatively high cost. 
       FIG.  2    shows an example of a front-end architecture  150  configured to operate with a single antenna  166  for the example bands B39 and B41 according to some implementations. More particularly, a power amplifier (PA) path  170  is shown to be configured to provide B39 TX operation, where an input signal to be amplified is provided at an input node  172 . A PA  174  (e.g., associated with a high-band (HB) 4G signal) can amplify such an input signal, and the amplified signal is provided to a band-selection switch  176  (e.g., a single-pull four-throw (SP4T) switch) configured to allow B39 TX operation. A B39 TX filter  177  is shown to be provided between the band-selection switch  176  and an antenna switch module (ASM)  164 . A phase shifting circuit  178  is shown to be provided between the B39 TX filter  177  and the ASM  164 . 
     A PA path  152  is shown to be configured to facilitate B41 TX and B41 RX operations. An input signal to be amplified is provided at an input node  154 . A PA  156  can amplify such an input signal, and the amplified signal is shown be provided to a band/mode selection switch  158  configured to allow B41 TX/RX operations. A B41 TX filter  159  is shown to be provided between the band/mode selection switch  108  and the ASM  164 . 
     In the example of  FIG.  2   , the ASM  164  can be configured as a multi-close switch to allow CA operations of the B39 and B41 bands with the single antenna  166 . For the B39 band, the ASM  164  can be operated to facilitate the TX operation through the foregoing PA path  170  and the RX operation through a B39 RX filter  179 . For the B41 band, the amplified and filtered RF signal can be routed to the antenna  166  for transmission through the band selection switch  158  and the ASM  164 , when in the B41 TX mode. When in the B41 RX mode, a signal received through the antenna  166  can be routed to the band/mode selection switch  158  through the ASM  166 . The band/mode selection switch  158  can then route the received signal to, for example, a low-noise amplifier (LNA) through a B41 RX node. 
     In the example of  FIG.  2   , a controller  160  is shown to provide one or more control functionalities for the operation of the B41 amplification path  152 . Further, the PA  156  is shown to be biased through a bias node  162 . Such control and biasing functionalities can also be provided for the B39 amplification path  170 . 
     In the foregoing example of  FIG.  2   , the phase shift provided by the phase shifting circuit  178  typically needs to be optimized or tuned to obtain desired system performance. Such optimization can be challenging, especially on small form factor boards such as a phone board. Further, RF performance can be easily degraded if optimized phase is not maintained. 
     In some implementations, a front-end architecture can include a switch configured to allow transmit and receive operations through a common node, but enables at different times. Along with such a switch, a B39/B41 duplexer can be implemented as described herein. Such a configuration can allow the front-end architecture to support some or all CA combinations with a single antenna, with a simpler implementation and elimination of a B39 RX filter. 
       FIG.  3    shows an example configuration  200  of a front-end architecture implemented on a multi-mode multi-band (MMMB) power amplifier module (PAM) according to some implementations. It will be understood that one or more features of such a front-end architecture can also be implemented in other types of modules or products. 
     While pertinent features are shown, those of ordinary skill in the art will appreciate from the present disclosure that various other features have not been illustrated for the sake of brevity and so as not to obscure more pertinent aspects of the example implementations disclosed herein. To that end, referring to the configuration  200  of  FIG.  3   , a power amplifier (PA) path  220  is shown to be configured to facilitate B39 TX and RX operations. An input signal to be amplified is provided at an input node  222 . A PA  224  can amplify such an input signal, and the amplified signal is shown be provided to a band-selection switch  226  configured to allow B39 TX operation. A B39/B41 duplexer  214  is shown to be provided between the band-selection switch  226  and an antenna switch module (ASM)  216 . 
     In  FIG.  3   , the band-selection switch  226  is shown to include a TX/RX switch  228  that facilitates the TX and RX operations for the B39 band. For example, during a TX operation, the switch  228  can be operated so that the output of the PA  224  is connected to a common node associated with the B39 portion of the duplexer  214 , and the B39 RX node is disconnected from the common node. During an RX operation, the switch  228  can be operated so that the output of the PA  224  is disconnected from the common node, and the B39 RX node is connected to the common node. In some implementations, the TX/RX switch  228  is configured to provide time-division duplexing (TDD) functionality for the amplified B39 TX signal and the B39 RX signal. 
     Referring to the configuration  200  of  FIG.  3   , a PA path  202  is shown to be configured to facilitate B41 TX and B41 RX operations. An input signal to be amplified is provided at an input node  204 . A PA  206  can amplify such an input signal, and the amplified signal is shown be provided to a band/mode selection switch  208  configured to allow B41 TX/RX operations. The B39/B41 duplexer  214  is shown to be provided between the band/mode selection switch  208  and the ASM  216 . 
     During a TX operation, the switch  208  can be operated so that the output of the PA  206  is connected to a common node associated with the B41 portion of the duplexer  214 , and the B41 RX node is disconnected from the common node. During an RX operation, the switch  208  can be operated so that the output of the PA  206  is disconnected from the common node, and the B41 RX node is connected to the common node. In some implementations, at least a portion of the switch  208  is a TX/RX switch that is configured to provide time-division duplexing (TDD) functionality for the amplified B41 TX signal and the B41 RX signal. 
     In the example of  FIG.  3   , a controller  210  is shown to provide one or more control functionalities for the operation of the B41 amplification path  202 . Further, the PA  206  is shown to be biased through a bias node  212 . Such control and biasing functionalities can also be provided for the B39 amplification path  220 . 
     In the example of  FIG.  3   , the ASM  216  is shown to allow routing of a path between the B39/B41 duplexer  214  and a common antenna  218 . A carrier aggregation of the B39 and B41 bands in the foregoing example manner can achieve similar functionality as in the example of  FIG.  2   , but with a lower component count, easier implementation, better performance, and a lower BoM cost. 
       FIG.  4    shows an example configuration  250  of a front-end architecture implemented on a TX front-end module (FEM) according to some implementations. It will be understood that one or more features of such a front-end architecture can also be implemented in other types of modules or products. 
     While pertinent features are shown, those of ordinary skill in the art will appreciate from the present disclosure that various other features have not been illustrated for the sake of brevity and so as not to obscure more pertinent aspects of the example implementations disclosed herein. To that end, referring to the configuration  250  of  FIG.  4   , a power amplifier (PA) path  270  is shown to be configured to facilitate B39 TX and RX operations. An input signal (e.g., associated with a high-band (HB) 2G/TD signal) to be amplified is shown to be provided through an input node  272 . A PA  274  can amplify such an input signal, and the amplified signal is shown be provided to matching network  280 . The input node  272  and the PA  274  can be configured to support multiple frequency bands, including the example B39 TX band. In the example shown, other band(s) can include a high-band (HB) signal for 2G/TD operation. For 2G operation, a low-band (LB) signal is shown to be provided to a PA  278  through an input node  276 , and the amplified signal from the PA  278  is shown to be provided to the matching network  280 . 
     In the example of  FIG.  4   , a TX/RX switch  282  is shown to be implemented to facilitate the TX and RX operations for the B39 band. For example, during a TX operation, the switch  282  can be operated so that the output of the PA  274  is connected to a common node associated with the B39 portion of the duplexer  264 , and the B39 RX node is disconnected from the common node. During an RX operation, the TX/RX switch  282  can be operated so that the output of the PA  274  is disconnected from the common node, and the B39 RX node is connected to the common node. In some implementations, the TX/RX switch  282  is configured to provide time-division duplexing (TDD) functionality for the amplified B39 TX signal and the B39 RX signal. 
     The TX/RX switch  282  can further be configured to allow routing of other non-B39 band(s) associated with the PA  274 . For example, the switch  282  can be operated so that the output of the PA  274  is routed to filters  284 ,  286 . In another example, the output PA  278  is routed to filter  288 . In some implementations, the switch  282  can optionally be operated so that the output PA  278  is routed to filter  288  (not shown). In the example of  FIG.  4   , a controller  290  is shown to provide one or more control functionalities for the operation of the B39 amplification path  270 . 
     Referring to the configuration  250  of  FIG.  4   , a PA path  252  is shown to be configured to facilitate B41 TX and B41 RX operations. An input signal to be amplified is provided at an input node  254 . A PA  256  can amplify such an input signal, and the amplified signal is shown be provided to a band/mode selection switch  258  configured to allow B41 TX/RX operations. The B39/B41 duplexer  264  is shown to be provided between the band/mode selection switch  258  and an antenna switch module (ASM)  292 . In some implementations, at least a portion of the switch  258  is a TX/RX switch that is configured to provide time-division duplexing (TDD) functionality for the amplified B41 TX signal and the B41 RX signal. 
     In the example of  FIG.  4   , a controller  260  is shown to provide one or more control functionalities for the operation of the B41 amplification path  252 . Further, the PA  256  is shown to be biased through a bias node  262 . Such control and biasing functionalities can also be provided for the B39 amplification path  270 . 
     In the example of  FIG.  4   , the ASM  292  is shown to allow routing of a path between the B39/B41 duplexer  264  and a common antenna  294 . A carrier aggregation of the B39 and B41 bands in the foregoing example manner can achieve similar functionality as in the example of  FIG.  2   , but with a less component count, easier implementation, better performance, and a lower BoM cost. 
       FIG.  5    shows that in some implementations, one or more features of the present disclosure can be implemented in a radio-frequency (RF) module  300 . While pertinent features are shown, those of ordinary skill in the art will appreciate from the present disclosure that various other features have not been illustrated for the sake of brevity and so as not to obscure more pertinent aspects of the example implementations disclosed herein. To that end, in some implementations, the RF module  300 , such as a front-end module (FEM) or a power amplifier module (PAM) for an RF device (e.g., a wireless device), has a substrate  306  (e.g., a laminate substrate). The RF module  300  can include a carrier aggregation (CA) architecture  302  having one or more features as described herein (e.g., the configuration  200  of a front-end architecture in  FIG.  3   , or the configuration  250  of a front-end architecture in  FIG.  4   ). In some implementations, the CA architecture  302  can be implemented on one or more semiconductor die. As also described herein, such a CA architecture  302  can provide CA functionalities with a common antenna  304 . 
     In some implementations, the RF module  300  is an architecture, a device, and/or a circuit having one or more features described herein can be included in an RF device such as a wireless device. Such an architecture, a device and/or a circuit can be implemented directly in the wireless device, in one or more modular forms as described herein, or in some combination thereof. 
       FIG.  6    schematically depicts an example radio-frequency (RF) device  400  having one or more advantageous features described herein. While pertinent features are shown, those of ordinary skill in the art will appreciate from the present disclosure that various other features have not been illustrated for the sake of brevity and so as not to obscure more pertinent aspects of the example implementations disclosed herein. To that end, in some implementations, the RF device  400  is a wireless device. In some implementations, such a wireless device can include, for example, a cellular phone, a smart-phone, a hand-held wireless device with or without phone functionality, a wireless tablet, a wireless router, a wireless access point, a wireless base station, etc. 
     In some implementations the RF device  400  includes one or more PAs in a PA module  412  configured to receive their respective RF signals from a transceiver  410  that can be configured and operated in known manners to generate RF signals to be amplified and transmitted, and to process received signals. The transceiver  410  is shown to interact with a baseband sub-system  408  that is configured to provide conversion between data and/or voice signals suitable for a user and RF signals suitable for the transceiver  410 . The transceiver  410  is also shown to be connected to a power management component  406  that is configured to manage power for the operation of the RF device  400 . Such power management can also control operations of the baseband sub-system  408  and other components of the RF device  400 . 
     The baseband sub-system  408  is shown to be connected to a user interface  402  to facilitate various input and output of voice and/or data provided to and received from the user. The baseband sub-system  408  can also be connected to a memory  404  that is configured to store data and/or instructions to facilitate the operation of the wireless device, and/or to provide storage of information for the user. 
     In the example RF device  400 , the PA module  412  can include one or more filters and/or one or more band/mode selection switches (collectively depicted as  413 ) configured to provide duplexing and/or switching functionalities as described herein. Such filters/switches  413  can be in communication with an antenna switch module (ASM)  416  having one or more features as described herein. In  FIG.  6   , some received signals are shown to be routed from the ASM  416  to one or more low-noise amplifiers (LNAs)  418 . Amplified signals from the LNAs  418  are shown to be routed to the transceiver  410 . According to some implementations, the PA module  412 , the filters/switches  413 , and/or the ASM  416  comprise at least a portion of the CA architecture  302  of the RF module  300  (e.g., the configuration  200  of a front-end architecture in  FIG.  3   , or the configuration  250  of a front-end architecture in  FIG.  4   ). 
     A number of other wireless device configurations can utilize one or more features described herein. For example, the RF device  400  does not need to be a multi-band device. In another example, the RF device  400  can include additional antennas such as diversity antenna, and additional connectivity features such as Wi-Fi, Bluetooth, and GPS. 
     One or more features of the present disclosure can be implemented with various cellular frequency bands as described herein. Examples of such bands are listed in Table 1. It will be understood that at least some of the bands can be divided into sub-bands. It will also be understood that one or more features of the present disclosure can be implemented with frequency ranges that do not have designations such as the examples of Table 1. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 Band 
                 Mode 
                 Tx Frequency Range (MHz) 
                 Rx Frequency Range (MHz) 
               
               
                   
               
             
            
               
                  B1 
                 FDD 
                   1,920-1,980 
                   2,110-2,170 
               
               
                  B2 
                 FDD 
                   1,850-1,410 
                   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 
                   1,400-1,920 
                   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 
               
               
                 B33 
                 TDD 
                   1,400-1,920 
                   1,400-1,920 
               
               
                 B34 
                 TDD 
                   2,010-2,025 
                   2,010-2,025 
               
               
                 B35 
                 TDD 
                   1,850-1,410 
                   1,850-1,410 
               
               
                 B36 
                 TDD 
                   1,930-1,990 
                   1,930-1,990 
               
               
                 B37 
                 TDD 
                   1,410-1,930 
                   1,410-1,930 
               
               
                 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 
               
               
                   
               
            
           
         
       
     
     For the purpose of description, it will be understood that “multiplexer,” “multiplexing” and the like can include “diplexer,” “diplexing” and the like. 
     Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” The word “coupled”, as generally used herein, refers to two or more elements that may be either directly connected, or connected by way of one or more intermediate elements. 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. 
     The above detailed description of embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise form disclosed above. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. For example, while processes or blocks are presented in a given order, alternative embodiments may perform routines having steps, or employ systems having blocks, in a different order, and some processes or blocks may be deleted, moved, added, subdivided, combined, and/or modified. Each of these processes or blocks may be implemented in a variety of different ways. Also, while processes or blocks are at times shown as being performed in series, these processes or blocks may instead be performed in parallel, or may be performed at different times. 
     The teachings of the invention provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various embodiments described above can be combined to provide further embodiments. 
     While some implementations 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.