ANTENNA SWAP ARCHITECTURES FOR TIME-DIVISION DUPLEXING COMMUNICATION SYSTEMS

Antenna swap architectures for time-division duplexing communication systems. In some embodiments, an antenna routing architecture can include first nodes including a transmit (Tx) node, a primary receive (PRx) node and a diversity receive (DRx) node. The antenna routing architecture can further include second nodes including a main antenna node and a diversity antenna node. The antenna routing architecture can further include a routing circuit configured to provide one or more radio-frequency (RF) signal paths between the first nodes and the second nodes. The routing circuit can be further configured such that each of the Tx node and the PRx node is capable of being independently coupled to the main antenna node or the diversity antenna node.

BACKGROUND

Field

The present disclosure relates to communication systems having duplexing capability.

Description of the Related Art

In some radio-frequency (RF) applications, uplink operations such as transmit operations and downlink operations such as receive operations can be performed generally concurrently. For example, time-division duplexing (TDD) utilizes a configuration where uplink operation and downlink operation can be performed approximately concurrently by use of different time slots in a given frequency band. In another example, frequency-division duplexing (FDD) utilizes a configuration where two different and sufficiently separated frequencies are utilized for uplink and downlink operations.

SUMMARY

According to a number of implementations, the present disclosure relates to an antenna routing architecture that includes first nodes including a transmit (Tx) node, a primary receive (PRx) node and a diversity receive (DRx) node, and second nodes including a main antenna node and a diversity antenna node. The antenna routing architecture further includes a routing circuit configured to provide one or more radio-frequency (RF) signal paths between the first nodes and the second nodes. The routing circuit is further configured such that each of the Tx node and the PRx node is capable of being independently coupled to the main antenna node or the diversity antenna node.

In some embodiments, the routing circuit can be further configured to include duplexing functionality. The duplexing functionality can include time-division duplexing (TDD) functionality. The PRx node can be coupled to the main antenna node, and the DRx node can be coupled to the diversity antenna node.

In some embodiments, the PRx node can be always coupled to the main antenna node, and the DRx node can be always coupled to the diversity antenna node. In some embodiments, the routing circuit can include a first switching circuit configured to couple the Tx node to the main antenna node or the diversity antenna node. The first switching circuit can be further configured to provide the coupling of the PRx node to the main antenna node, and to provide the coupling of the DRx node to the diversity antenna node.

In some embodiments, the routing circuit can include a first TDD filter implemented between the first switching circuit and the main antenna node. The first TDD filter can be configured to allow TDD operation involving an amplified Tx signal associated with the Tx node and an Rx signal associated with the PRx node when the main antenna node is being utilized for the TDD operation.

In some embodiments, the routing circuit can further include a lossy path between the first switching circuit and the DRx node. The routing circuit can further include a low-noise amplifier (LNA) implemented between the lossy path and the DRx node, and the LNA can be configured to provide amplification for an Rx signal received through the DRx node.

In some embodiments, the routing circuit can further include a switchable path configured to selectively bypass the LNA. The routing circuit can include a bypass switch assembly implemented to allow routing of the Rx signal from the DRx node to the LNA, or to allow routing of an amplified Tx signal associated with the Tx node through the switchable bypass path. The bypass switch assembly can include a first switch between the DRx node and the LNA, and a second switch parallel with the first switch and between the DRx node and the lossy path.

In some embodiments, the first switch can be the only switch between the DRx node and the LNA, such that the Rx signal experiences a relatively low loss due to the only switch. The bypass switch assembly can further include a third switch between the LNA and the lossy path. In some embodiments, the second switch can be the only switch between the lossy path and the DRx node, such that the amplified Tx signal experiences a relatively low loss due to the only switch.

In some embodiments, the routing circuit can further include a second TDD filter implemented between the first bypass switch and the DRx node. The second TDD filter can be configured to allow TDD operation involving the amplified Tx signal and the Rx signal from the DRx node when the diversity antenna node is being utilized for the TDD operation. The first switching circuit and the bypass switch assembly can be configured to operate in cooperation to allow TDD operation involving the amplified Tx signal associated with the Tx node and the Rx signal associated with the DRx node when the diversity antenna node is being utilized for the TDD operation.

In some embodiments, the routing circuit can include a first switching circuit and a second switching circuit configured to couple the Tx node to the main antenna node or the diversity antenna node. The routing circuit can include a first TDD filter implemented between the first switching circuit and the second switching circuit. The first TDD filter can be configured to allow TDD operation involving an amplified Tx signal associated with the Tx node and an Rx signal associated with the PRx node when the main antenna node is being utilized for the TDD operation.

In some embodiments, the first switching circuit and the second switching circuit can be further configured to provide the coupling of the PRx node to the main antenna node. The second switching circuit can be further configured to provide the coupling of the DRx node to the diversity antenna node. The routing circuit can further include a lossy path between the second switching circuit and the DRx node. The routing circuit can further include a low-noise amplifier (LNA) and a second TDD filter implemented between the lossy path and the DRx node, with the LNA being configured to provide amplification for an Rx signal received through the DRx node. The routing circuit can further include a switchable path configured to selectively bypass the second TDD filter and the LNA. The routing circuit can include a bypass switch assembly implemented to allow routing of the Rx signal from the DRx node to the second TDD filter and the LNA, or to allow routing of an amplified Tx signal associated with the Tx node through the switchable bypass path. The bypass switch assembly can include a first switch between the DRx node and the second TDD filter, and a second switch parallel with the first switch and between the DRx node and the lossy path.

In some embodiments, the first switch can be the only switch between the DRx node and the LNA, such that the Rx signal experiences a relatively low loss due to the only switch. The bypass switch assembly can further include a third switch between the LNA and the lossy path. In some embodiments, the second switch can be the only switch between the lossy path and the DRx node, such that the amplified Tx signal experiences a relatively low loss due to the only switch.

In some embodiments, the second TDD filter can be configured to provide filtering functionality for the LNA. The second switching circuit and the bypass switch assembly can be configured to operate in cooperation to allow TDD operation involving the amplified Tx signal associated with the Tx node and the Rx signal associated with the DRx node when the diversity antenna node is being utilized for the TDD operation.

In some embodiments, the first and second switching circuits can be further configured to provide the coupling of the DRx node to the diversity antenna node. The routing circuit can further include a PRx/DRx switching circuit implemented between the first switching circuit and the PRx and DRx nodes. The PRx/DRx switching circuit can be configured to allow a DRx signal to be output to the DRx node even if it was obtained from the main antenna node, and to allow a PRx signal to be output to the PRx node even if it was obtained from the diversity antenna node. The PRx/DRx switching circuit can include a cross-point configuration.

In some embodiments, the routing circuit can further include a lossy path between the second switching circuit and the DRx node. The routing circuit can further include a low-noise amplifier (LNA) and a second TDD filter implemented between the lossy path and the DRx node, and the LNA can be configured to provide amplification for an Rx signal received through the DRx node.

In some embodiments, the routing circuit can further include a switchable path configured to selectively bypass the second TDD filter and the LNA. The routing circuit can include a bypass switch assembly implemented to allow routing of the Rx signal from the DRx node to the second TDD filter and the LNA, or to allow routing of an amplified Tx signal associated with the Tx node through the switchable bypass path. The bypass switch assembly can include a first switch between the DRx node and the second TDD filter, and a second switch parallel with the first switch and between the DRx node and the lossy path. The first switch can be the only switch between the DRx node and the LNA, such that the Rx signal experiences a relatively low loss due to the only switch. The bypass switch assembly can further include a third switch between the LNA and the lossy path. The second switch can be the only switch between the lossy path and the DRx node, such that the amplified Tx signal experiences a relatively low loss due to the only switch.

In some embodiments, the second TDD filter can be configured to provide filtering functionality for the LNA. The second switching circuit and the bypass switch assembly can be configured to operate in cooperation to allow TDD operation involving the amplified Tx signal associated with the Tx node and the Rx signal associated with the DRx node when the diversity antenna node is being utilized for the TDD operation.

In some implementations, the present disclosure relates to a time-division duplexing (TDD) architecture that includes a primary path configured for TDD operations involving a main antenna. The primary path has a single filter configured to support the TDD operations including a transmit (Tx) operation and a primary receive (PRx) operation with the main antenna. The TDD architecture further includes a diversity path configured for TDD operations involving a diversity antenna. The diversity path has a single filter configured to support the TDD operations including the Tx operation and a diversity receive (DRx) operation with the diversity antenna.

According to some teachings, the present disclosure relates to a method for performing time-division duplexing (TDD) of radio-frequency (RF) signals. The method includes maintaining a primary receive (PRx) connectivity to a main antenna, maintaining a diversity receive (DRx) connectivity to a diversity antenna, and swapping a transmit (Tx) connectivity between the main antenna and the diversity antenna.

In some embodiments, the swapping of the Tx connectivity can be performed without changing the PRx connectivity.

In a number of implementations, the present disclosure relates to a time-division duplexing (TDD) architecture having a primary path configured for TDD operations involving a main antenna, and a diversity path configured for TDD operations involving a diversity antenna. The TDD architecture further includes a first switching circuit configured to allow a transmit (Tx) signal to be routed to the main antenna or the diversity antenna, and a second switching circuit configured to allow a primary receive (PRx) signal to be obtained from the diversity antenna and be output to a PRx pin, and to allow a diversity receive (DRx) signal to be obtained from the main antenna and be output to a DRx pin.

In some implementations, the present disclosure relates to a wireless device that includes a transceiver configured to process radio-frequency (RF) signals, a main antenna and a diversity antenna, each in communication with the transceiver, and an antenna routing system implemented between the transceiver and the main and diversity antennas. The antenna routing system includes first nodes having a transmit (Tx) node, a primary receive (PRx) node and a diversity receive (DRx) node. The antenna routing system further includes second nodes having a main antenna node and a diversity antenna node. The antenna routing system further includes a routing circuit configured to provide one or more RF signal paths between the first nodes and the second nodes. The routing circuit is further configured such that each of the Tx node and the PRx node is capable of being independently coupled to the main antenna node or the diversity antenna node.

According to some implementations, the present disclosure relates to a wireless device having a transceiver configured to process radio-frequency (RF) signals, a main antenna and a diversity antenna, each in communication with the transceiver, and a time-division duplexing (TDD) architecture including a primary path configured for TDD operations involving the main antenna. The primary path has a single filter configured to support the TDD operations including a transmit (Tx) operation and a primary receive (PRx) operation with the main antenna. The TDD architecture further includes a diversity path configured for TDD operations involving the diversity antenna. The diversity path has a single filter configured to support the TDD operations including the Tx operation and a diversity receive (DRx) operation with the diversity antenna.

In some implementations, the present disclosure relates to a wireless device having a transceiver configured to process radio-frequency (RF) signals, a main antenna and a diversity antenna, each in communication with the transceiver, and a time-division duplexing (TDD) architecture including a primary path configured for TDD operations involving the main antenna, and a diversity path configured for TDD operations involving the diversity antenna. The TDD architecture further includes a first switching circuit configured to allow a transmit (Tx) signal to be routed to the main antenna or the diversity antenna. The TDD architecture further includes a second switching circuit configured to allow a primary receive (PRx) signal to be obtained from the diversity antenna and be output to a PRx pin in communication with the transceiver, and to allow a diversity receive (DRx) signal to be obtained from the main antenna and be output to a DRx pin in communication with the transceiver.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

FIG. 1shows a block diagram of an antenna routing system or architecture100having one or more features as described herein. Such an architecture can be configured to route radio-frequency (RF) signals between a plurality of nodes associated with transmit (Tx) and receive (Rx) operations and a plurality of antenna nodes. It will be understood that such antenna nodes can be connected to their respective antennas.

In the example ofFIG. 1, the plurality of nodes associated with Tx and Rx operations are indicated as “Tx” for a transmit portion of a first frequency band, “Rx1” for a receive portion of the first frequency band, and “Rx2” for a receive portion of a second frequency band. RF signals associated with such nodes can be routed to and/or from a first antenna (Ant.1) and a second antenna (Ant.2). In some embodiments, the TX and Rx1operations can be serviced with the first antenna, and the Rx2operation can be serviced with the second antenna. However, there may be situations where one or more swapping of antenna assignments for the Tx, Rx1and Rx2operations is/are desirable. As described herein, the antenna routing architecture100as described herein can provide such antenna swapping functionality in an efficient manner.

FIG. 2shows that in some embodiments, the first antenna (Ant.1) and the second antenna (Ant.2) ofFIG. 1can be a main antenna (Main) and a diversity antenna (Diversity). In such a context, Tx and Rx1can be transmit and receive portions of a primary frequency band primarily assigned to operate with the main antenna. Rx2can be a receive portion of a diversity frequency band assigned to operate with the diversity antenna. Accordingly, for the purpose of description, Rx1and Rx2can be indicated as PRx (primary receive) and DRx (diversity receive), respectively.

In an example context of wireless handsets such as cellular mobile devices, it is noted that such handsets are typically designed to have one antenna system on one end of the phone, and another antenna system on the other end. Such a configuration is designed to support multiple radio coexistence with increased isolation, and to achieve required or desired envelope correlation performance between intended independent antennas. Such support of multiple receivers for each active receive (Rx) link typically involves simultaneous primary Rx (PRx) and diversity Rx (DRx) operations on these two antenna systems at the same time.

To optimize or improve Rx performance, a low-noise amplifier (LNA) is preferably implemented as close as possible to each antenna to thereby reduce loss before the LNA, and to increase overall Rx signal-to-noise ratio (SNR). Such an LNA typically has a filter implemented before it to attenuate blocking signals that can exceed the LNA's linearity limits.

In the foregoing configuration with the near and remote antenna systems on either sides of the handset, it is desirable to be able to switch between these two antennas in an event that one of the antennas is in a state (e.g., loaded, obscured, and/or detuned) that does not allow the intended balance of ideal operation. Such a swap of antennas is typically required for transmit (Tx) operation, so that an amplified RF signal is routed to one of the two antennas.

FIG. 3shows a block diagram of an antenna routing system10configured to utilize a main antenna (Main) and a diversity antenna (Diversity). The antenna routing system10can route RF signals associated with Tx, PRx and DRx operations through various circuits therein. For example, the Tx and PRx operations can be duplexed by a duplexer circuit12so as to allow use of a common path14that supports both Tx and PRx operations. Such a common Tx/PRx path is shown to be coupled to a switch circuit16that can allow routing between the common Tx/PRx path14and either of the main and diversity antennas.

In the example ofFIG. 3, the DRx operation is shown to be supported by a diversity path18coupled to the switch circuit16. The switch circuit16can also allow routing between the diversity path18and either of the main and diversity antennas.

In the example ofFIG. 3, a path between the switch circuit16and the diversity antenna can include a circuit20configured to support the DRx operation or a bypass mode (e.g., when the diversity antenna is being used for non-DRx operation). Examples of such a circuit are described herein in greater detail.

FIG. 4Ashows the antenna routing system10ofFIG. 3in a first mode in which the common Tx/PRx path14is coupled to the main antenna (depicted as signal route22), and the diversity path18is coupled to the diversity antenna (depicted as signal route24), by the switch circuit16.FIG. 4Bshows the same antenna routing system10in a second mode in which the common Tx/PRx path14is coupled to the diversity antenna (depicted as signal route26), and the diversity path18is coupled to the main antenna (depicted as signal route28), by the switch circuit16.

It is noted that in both of the first and second modes ofFIGS. 4A and 4B, the Tx and PRx operations are tied together through the common Tx/PRx path14. As described herein, when such a constraint is removed, a number of antenna swapping configurations having desirable features can be implemented.

In the examples ofFIGS. 3 and 4, the duplexing (DPX) functionality between Tx and PRx operations can be frequency-division duplexing (FDD) or time-division duplexing (TDD).FIG. 5shows an example of an FDD architecture in which Tx and PRx operations are tied together through a common Tx/PRx path when being coupled to either of the main and diversity antennas. Similarly,FIG. 6shows an example of a TDD architecture in which Tx and PRx operations are tied together through a common Tx/PRx path when being coupled to either of the main and diversity antennas.

InFIG. 5, an example FDD architecture30is shown to include a switch circuit33that can couple a common Tx/PRx path47to a main antenna34or a diversity antenna46. For example, switch nodes33aand33bcan be connected (depicted as a solid line) to provide a route between the common Tx/PRx path47and the main antenna34. Similarly, switch nodes33aand33dcan be connected (depicted as a solid line) to provide a route between the common Tx/PRx path47and the diversity antenna46.

The switch circuit33can also couple a diversity path48to the main antenna34or the diversity antenna46. For example, switch nodes33cand33dcan be connected (depicted as a dashed line) to provide a route between the diversity path48and the diversity antenna46. Similarly, switch nodes33cand33bcan be connected (depicted as a dashed line) to provide a route between the diversity path48and the main antenna34.

In the example ofFIG. 5, the common Tx/PRx path47is shown to be coupled to Tx and PRx nodes through an FDD duplexer32(having a Tx filter32aand an Rx filter32b). The Tx portion of the duplexer32is shown to be coupled to an output of a power amplifier (PA)31. The Rx portion of the duplexer32is shown to be coupled to an input of an LNA35. A bypass path can be provided for the LNA35utilizing a switch36.

In the example ofFIG. 5, the diversity path48is shown to be coupled to a DRx node through a filter39and an LNA37. A bypass path can be provided for the LNA37utilizing a switch38. In the example shown, the LNA37can be operational (with switch38open) when the diversity path48is coupled to the main antenna34, or be non-operational (with switch38closed to provide bypass) when the diversity path48is coupled to the diversity antenna46. Such turning off of the LNA37in the latter example can be achieved when there is an LNA near the diversity antenna, as shown in the example ofFIG. 5.

In the example ofFIG. 5, the switch node33dof the switch circuit33is shown to be coupled to the diversity antenna46through a switch circuit45, a filter44, an LNA42, a switch circuit41, and a relatively lengthy and lossy path indicated as40.

In the example ofFIG. 5, switch nodes45cand45aof the switch circuit45can be connected (depicted as a dashed line), and switch nodes41cand41aof the switch circuit41can be connected (depicted as a dashed line), when the DRx operation is being performed through the diversity antenna46. In such a mode, the LNA42can be operational (with switch43open), and the downstream LNA37may or may not be operational.

In the example ofFIG. 5, switch nodes45cand45bof the switch circuit45can be connected (depicted as a solid line), and switch nodes41band41aof the switch circuit41can be connected (depicted as a solid line), when the duplexed Tx/PRx operations are being performed through the diversity antenna46. In such a mode, the filter44and the LNA42can be bypassed through a bypass path between the switch nodes45band41b.

InFIG. 6, an example TDD architecture50is shown to include a switch circuit54that can couple a common Tx/PRx path69to a main antenna56or a diversity antenna68. For example, switch nodes54aand54bcan be connected (depicted as a solid line) to provide a route between the common Tx/PRx path69and the main antenna56. Similarly, switch nodes54aand54dcan be connected (depicted as a solid line) to provide a route between the common Tx/PRx path69and the diversity antenna68.

The switch circuit54can also couple a diversity path70to the main antenna56or the diversity antenna68. For example, switch nodes54cand54dcan be connected (depicted as a dashed line) to provide a route between the diversity path70and the diversity antenna68. Similarly, switch nodes54cand54bcan be connected (depicted as a dashed line) to provide a route between the diversity path70and the main antenna56.

In the example ofFIG. 6, the common Tx/PRx path69is shown to be coupled to Tx and PRx nodes through a Tx/Rx filter53and a Tx/Rx switch52. The Tx/Rx switch52can be operated so as to provide TDD functionality between Tx and PRx modes. For example, switch node52ccan be connected to switch node52bfor Tx operation, or to switch node52afor PRx operation in a switching sequence. Accordingly, when the switch nodes52cand52bare connected for Tx operation, an output of a PA51can be connected to the Tx/Rx filter53. Similarly, when the switch nodes52cand52aare connected for PRx operation, the Tx/Rx filter53can be connected to an input of an LNA57. A bypass path can be provided for the LNA57utilizing a switch58.

In the example ofFIG. 6, the diversity path70is shown to be coupled to a DRx node through a filter61and an LNA59. A bypass path can be provided for the LNA59utilizing a switch60. In the example shown, the LNA59can be operational (with switch60open) when the diversity path70is coupled to the main antenna56, or be non-operational (with switch60closed to provide bypass) when the diversity path70is coupled to the diversity antenna68. Such turning off of the LNA59in the latter example can be achieved when there is an LNA near the diversity antenna, as shown in the example ofFIG. 6.

In the example ofFIG. 6, the switch node54dof the switch circuit54is shown to be coupled to the diversity antenna68through a switch circuit67, a filter66, an LNA64, a switch circuit63, and a relatively lengthy and lossy path indicated as62.

In the example ofFIG. 6, switch nodes67cand67aof the switch circuit67can be connected (depicted as a dashed line), and switch nodes63cand63aof the switch circuit63can be connected (depicted as a dashed line), when the DRx operation is being performed through the diversity antenna68. In such a mode, the LNA64can be operational (with switch65open), and the downstream LNA59may or may not be operational.

In the example ofFIG. 6, switch nodes67cand67bof the switch circuit67can be connected (depicted as a solid line), and switch nodes63band63aof the switch circuit63can be connected (depicted as a solid line), when the duplexed Tx/PRx operations are being performed through the diversity antenna68. In such a mode, the filter66and the LNA64can be bypassed through a bypass path between the switch nodes67band63b.

In the examples ofFIGS. 3-6, duplexed Tx/PRx operations (in FDD or TDD mode) are tied together through a common Tx/PRx path. Accordingly, the PRx operation depends on such a common Tx/PRx path, and therefore on Tx operation.

FIG. 7shows that in some embodiments, an antenna routing system or architecture100can include a duplexing system101configured to provide independent routing of RF signals associated with Tx and PRx operations. For the purpose of description, it will be understood that such independent routing can include a configuration where Tx and PRx operations do not necessarily need to be associated together with a given antenna (e.g., main antenna or diversity antenna). It will also be understood that such independent routing may or may not include a common signal path utilized by both Tx and PRx operations.

In the example ofFIG. 7, the duplexing system101is shown to provide various routing of RF signals between a plurality of input/output (I/O) nodes104and a plurality of antenna nodes106. The I/O nodes104can include Tx and PRx nodes corresponding to a duplexed frequency band(s), and a DRx node corresponding to a diversity frequency band. For the purpose of description, the Tx node can be on the input side or the output side of a PA. Similarly, the PRx node can be on the input side or the output side of an LNA. Similarly, the DRx node can be on the input side or the output side of an LNA, if such an LNA exists. Also for the purpose of description, the antenna nodes106can be nodes implemented on one or more modules (e.g., on a common module or on separate modules), nodes implemented in a circuit board such as a phone board, or any combination thereof, where such nodes are connected to or connectable to their respective antennas.

In the example ofFIG. 7, the antenna routing system100is shown to further include a DRx circuit108having bypass capability. Examples related to such a circuit are described herein in greater detail.

In some embodiments, the antenna routing system100ofFIG. 7can be implemented as a TDD system.FIGS. 8-16show various examples of such a TDD system.

FIG. 8shows an example TDD antenna routing system100that can be implemented with a reduced number of filters. Such an antenna routing system100can include a switching circuit104configured to provide both Tx/Rx TDD functionality, as well as antenna selection functionality. For example, switch node104aof the switching circuit104can be coupled to a Tx node through a PA102, and switch node104cof the switching circuit104can be coupled to a PRx node through an LNA110. A bypass path can be provided for the LNA110utilizing a switch112. Switch node104bof the switching circuit104can be coupled to a main antenna108through a first TDD filter (TDD1)106. Switch node104dof the switching circuit104can be coupled to a diversity antenna124through a second TDD filter (TDD2)122, a switch circuit120, an LNA118, a switch circuit116, and a relatively lengthy and lossy path indicated as114. Switch node104eof the switching circuit104can be coupled to a DRx node.

In the example ofFIG. 8, PRx operation can be assigned to the main antenna108. Accordingly, switch node104bis shown to be connected to switch node104c(depicted as a dashed line). Similarly, DRx operation can be assigned to the diversity antenna124. Accordingly, switch node104dis shown to be connected to switch node104e(depicted as a dashed line).

In the example ofFIG. 8, Tx operation can be assigned to the main antenna108or the diversity antenna124. Accordingly, switch node104acan be connected to switch node104b(depicted as a solid line) or to switch node104d(also depicted as a solid line). When the main antenna108is utilized for Tx operation, Tx and PRx can be time-division duplexed as shown inFIG. 9A. When the diversity antenna124is utilized for Tx operation, Tx and DRx can be time-division duplexed as shown inFIG. 9B.

In the example ofFIG. 8, switch nodes120cand120aof the switch circuit120can be connected (depicted as a dashed line), and switch nodes116cand116aof the switch circuit116can be connected (depicted as a dashed line), when the LNA118is to be utilized. Similarly, switch nodes120cand120bof the switch circuit120can be connected (depicted as a solid line), and switch nodes116band116aof the switch circuit116can be connected (depicted as a solid line), when the LNA118is to be bypassed.

In the example ofFIG. 8, the foregoing portion of the TDD antenna routing system100involving use of or bypassing of the LNA118between nodes126and129is indicated as125. An example of a switching scheme that can be utilized for such functionality is shown inFIG. 10.FIGS. 11A and 11Bshow examples of switching configurations of such a switching scheme for effectuating the example operating modes ofFIGS. 9A and 9B.

FIG. 9Ashows an example configuration in which the TDD antenna routing system100ofFIG. 8utilizes the main antenna108for Tx operation. In such a configuration, TDD can be achieved by switching actions (indicated as105) involving the switch circuit104. For example, switch nodes104band104acan be connected when the TDD operation is in a Tx mode; and switch nodes104band104ccan be connected when the TDD operation is in a PRx mode.

In the example ofFIG. 9A, DRx operation can be achieved through the diversity antenna124. Accordingly, the LNA118can be utilized, and to facilitate such LNA operation, switch nodes120cand120aof the switch circuit120, as well as switch nodes116cand116aof the switch circuit116, can be connected as shown.

FIG. 9Bshows an example configuration in which the TDD antenna routing system100ofFIG. 8utilizes the diversity antenna124for Tx operation. In such a configuration, TDD can be achieved by switching actions (indicated as107) involving the switch circuit104. For example, switch nodes104dand104acan be connected when the TDD operation is in a Tx mode; and switch nodes104dand104ecan be connected when the TDD operation is in a DRx mode.

In the example ofFIG. 9B, PRx operation can be maintained utilizing the main antenna108. Accordingly, switch nodes104band104cof the switch circuit104can remain connected as shown.

In the example ofFIG. 9B, the TDD operation involving the diversity antenna124can be facilitated by the portion125along the DRx amplification path. For example, when the TDD operation is in a Tx mode, the LNA118can be bypassed by having switch nodes120cand120bof the switch circuit120connected (depicted as a solid line), and switch nodes116band116aof the switch circuit116connected (depicted as a solid line). When the TDD operation is in a DRx mode, the LNA118can amplify the received signal (from the diversity antenna124) by having switch nodes120cand120aof the switch circuit120connected (depicted as a dashed line), and switch nodes116cand116aof the switch circuit116connected (depicted as a dashed line). In some embodiments, the foregoing switching actions (depicted as121and117) for TDD operation can be performed in cooperation with the switching action107involving the switch circuit104.

In the example ofFIGS. 8 and 9, there are two filters (TDD1and TDD2) that can facilitate the various TDD operations. In some embodiments, each of such filters can be configured with sufficient pass-band width to accommodate frequency bands associated with Tx and DRx operations, while providing sufficient performance characteristics. Such frequency bands can overlap, or be separated by a relatively small frequency gap. In the context of overlapping frequency bands, such bands can partially or fully overlap. For example, B38 band (2570 MHz to 2620 MHz) is contained entirely within B41 band (2496 MHz to 2690 MHz). In another example, A-XGP band (2545 MHz to 2575 MHz) overlaps slightly with the B38 band (2570 MHz to 2620 MHz). It will be understood that other combinations of bands can be utilized.

FIG. 10shows an example of a switching configuration that can be implemented between the nodes126and129ofFIGS. 8 and 9, for the portion125of the DRx amplification path. Such a switching configuration can include a switch circuit123in which switch S1can be provided between nodes126and127, with the node127being on the input side of the LNA118. Another switch S2can be provided between nodes128and129, with the node128being on the output side of the LNA118. Accordingly, the switch S1, the LNA118, and the switch S2form one path between the nodes126and129. An electrically parallel path between the nodes126and129is shown to include a switch S3.

In the foregoing example ofFIG. 10, it is noted that relatively low loss can be realized in the bypass path with use of a single switch (S3) when bypassing of the LNA118is desired (e.g., during a Tx mode). It is also noted that relatively low loss can also be realized for a signal received through the diversity antenna (124inFIGS. 8 and 9) and being provided to the LNA118, with use of a single switch (S1) when the LNA118is being utilized (e.g., during a receive mode). It will be understood that other switching configurations can also be utilized.

FIG. 11Ashows an example of how the switches S1to S3can be operated when the LNA118is being utilized (e.g., during a receive mode). In such a mode, S1and S2before and after the LNA118can be closed, and S3can be opened. The example configuration ofFIG. 11Acan correspond to, for example, the DRx phase of the TDD operation described in reference toFIG. 9B. The same configuration ofFIG. 11Acan also facilitate the DRx operation ofFIG. 9A.

FIG. 11Bshows an example of how the switches S1to S3can be operated when the LNA118is being bypassed (e.g., during a Tx mode). In such a mode, S1and S2before and after the LNA118can be opened, and S3can be closed. The example configuration ofFIG. 11Bcan correspond to, for example, the Tx phase of the TDD operation (with the diversity antenna) described in reference toFIG. 9B.

In the context of the TDD operation (with the diversity antenna) ofFIG. 9B, the TDD switching actions (depicted as121and117) can correspond to switching between the configurations ofFIGS. 11A and 11B. As described herein, such TDD switching actions can be performed in cooperation with the switching action107of the switch circuit104inFIG. 9B.

FIG. 12shows another example TDD antenna routing system100that can be implemented with a reduced number of filters. In the example ofFIG. 12, functionalities associated with the switch circuit104ofFIG. 8can be implemented as first and second switch circuit blocks130and132. In some embodiments, the second switch circuit block132can be part of an antenna switch module (ASM); and presence of such a second switch circuit block can provide, among others, support for carrier aggregation (CA).

By way of non-limiting examples, carrier aggregation of a plurality of simultaneous RF paths can be supported through a number of implementations. For example, separate ASMs and band groups of RF paths dedicated to them can be routed to separate antennas and leverage the antenna-to-antenna isolation for further benefit between the separate bands to be carrier aggregated.

In another example, separate ASMs can be combined with another set of grouped bands through another ASM with use of a diplex filter to merge the two RF paths into a single shared common path going to a common antenna feed. If the bands to be aggregated have reasonably large frequency separation, then the bands can be merged to a common antenna feed in this way with fairly low loss.

In yet another example, bands can be permanently “ganged” together at their shared common ANT port and be switched in appropriately. In yet another example, filters can be electrically switched into connection through a use of simultaneous switch throws in common switching circuits (e.g., switching circuits132,120inFIG. 12).

Referring toFIG. 12, the antenna routing system100can include a first switching circuit block130configured to provide Tx/PRx TDD functionality. For example, switch node130acan be coupled to a Tx node through a PA102, and switch node130ccan be coupled to a PRx node through an LNA110. A bypass path can be provided for the LNA110utilizing a switch112. Switch node130bcan be coupled to a second switching circuit block132(e.g., implemented as an ASM) through a first TDD filter (TDD1)106.

Referring to the second switching circuit block132ofFIG. 12, switch node132acan be coupled to the first TDD filter (TDD1)106, and switch node132bcan be coupled to a main antenna108. Switch node132ccan be coupled to a DRx node, and switch node132dcan be coupled to a diversity antenna124through a switch circuit120, a second TDD filter (TDD2)122, an LNA118, a switch circuit116, and a relatively lengthy and lossy path indicated as114.

With the foregoing example configuration ofFIG. 12, PRx operation can be assigned to the main antenna108by the ASM132. Accordingly, switch node132bis shown to be connected to switch node134a(depicted as a dashed line) during PRx operation. Similarly, DRx operation can be assigned to the diversity antenna124by the ASM132. Accordingly, switch node132dis shown to be connected to switch node132c(depicted as a dashed line).

In the example ofFIG. 12, Tx operation can be assigned to the main antenna108or the diversity antenna124. Accordingly, switch node132acan be connected to switch node132b(depicted as a solid line) or to switch node132d(also depicted as a solid line). When the main antenna108is utilized for Tx operation, Tx and PRx can be time-division duplexed as shown inFIG. 13A. When the diversity antenna124is utilized for Tx operation, Tx and DRx can be time-division duplexed as shown inFIG. 13B.

In the example ofFIG. 12, switch nodes120cand120aof the switch circuit120can be connected (depicted as a dashed line), and switch nodes116cand116aof the switch circuit116can be connected (depicted as a dashed line), when the LNA118is to be utilized. Similarly, switch nodes120cand120bof the switch circuit120can be connected (depicted as a solid line), and switch nodes116band116aof the switch circuit116can be connected (depicted as a solid line), when the LNA118is to be bypassed.

In the example ofFIG. 12, the foregoing portion of the TDD antenna routing system100involving use of or bypassing of the LNA118between nodes138and141is indicated as125. An example of a switching scheme that can be utilized for such functionality is shown inFIG. 14.FIGS. 15A and 15Bshow examples of switching configurations of such a switching scheme for effectuating the example operating modes ofFIGS. 13A and 13B.

It is noted that in some embodiments, the example switching functionality provided by, for example, switching circuits132,116and120can be extended to support one or more additional RF paths. As described herein, each of such additional RF path(s) can include separate band support and specific filtering as required or desired, simply by addition of switch throws and connectivity.

FIG. 13Ashows an example configuration in which the TDD antenna routing system100ofFIG. 12utilizes the main antenna108for Tx operation. In such a configuration, TDD can be achieved between Tx and PRx modes by switching actions (indicated as105) involving the Tx/PRx switch circuit130. For example, switch nodes130aand130bcan be connected when the TDD operation is in a Tx mode; and switch nodes130band130ccan be connected when the TDD operation is in a PRx mode.

In the example ofFIG. 13A, the connection of switch nodes132aand132bof the ASM132allows the Tx/PRx TDD operation to be performed with the main antenna. As described herein, when the Tx operation is to be performed with the diversity antenna, the PRx operation can remain with the main antenna. Accordingly, routing for PRx operation does not necessarily depend on the routing for Tx operation.

In the example ofFIG. 13A, DRx operation can be achieved through the diversity antenna124. Accordingly, the LNA118can be utilized, and to facilitate such LNA operation, switch nodes120cand120aof the switch circuit120, as well as switch nodes116cand116aof the switch circuit116, can be connected as shown.

In the example ofFIG. 13A, the DRx operation can optionally include a second LNA134downstream from the ASM132. A bypass path can be provided for the LNA134utilizing a switch136.

FIG. 13Bshows an example configuration in which the TDD antenna routing system100ofFIG. 12utilizes the diversity antenna124for Tx operation. In such a configuration, TDD can be achieved between Tx and DRx modes by switching actions (indicated as107) involving the ASM132. For example, switch nodes132dand132acan be connected when the TDD operation is in a Tx mode; and switch nodes132dand132ccan be connected when the TDD operation is in a DRx mode.

In the example ofFIG. 13B, PRx operation can remain with use of the main antenna108. Accordingly, switch nodes132band132aof the ASM132can remain connected as shown. For the Tx/PRx switch circuit130, switching action indicated as105can be performed in cooperation with the switching action107of the ASM132. Thus, when in a Tx mode, switch nodes130aand130bof the Tx/Rx switch circuit130can be connected; and when in a PRx mode, switch nodes130band130cof the Tx/Rx switch circuit130can be connected.

In the example ofFIG. 13B, the TDD operation involving the diversity antenna124can be facilitated by the portion125along what is normally a DRx amplification path. For example, when the TDD operation is in a Tx mode, the second TDD filter (TDD2)122and the LNA118can be bypassed by having switch nodes120cand120bof the switch circuit120connected (depicted as a solid line), and switch nodes116band116aof the switch circuit116connected (depicted as a solid line). When the TDD operation is in a receive mode, the LNA118can amplify the received signal (from the diversity antenna124), filtered by the second TDD filter (TDD2)122, by having switch nodes120cand120aof the switch circuit120connected (depicted as a dashed line), and switch nodes116cand116aof the switch circuit116connected (depicted as a dashed line). In some embodiments, the foregoing switching actions (depicted as121and117) for TDD operation can be performed in cooperation with the switching action107involving the ASM132.

In the example ofFIGS. 12 and 13, there are two filters (TDD1and TDD2) that can facilitate the various TDD operations. The second TDD filter (TDD2)122is shown to be bypassed completely when Tx operation is being performed through the diversity antenna124. Thus, the two filters (TDD1and TDD2) may or may not be configured to have overlapping frequency bands. For example, frequency bands associated with Tx and DRx modes do not need to overlap.

In some embodiments, the foregoing configuration of filters can be utilized in lower power applications such as machine type communications that utilize half-duplex operation such as TDD operation. Such applications can utilize TDD operation between separate paired bands of normally TDD spectrum to, for example, relax filtering requirements and self-desense degradation.

FIG. 14shows an example of a switching configuration that can be implemented between the nodes138and141ofFIGS. 12 and 13, for the portion125of the DRx amplification path. Such a switching configuration can include a switch circuit123in which switch S1can be provided between nodes138and139, with the node139being on the input side of the LNA118(through the filter122). Another switch S2can be provided between nodes140and141, with the node140being on the output side of the LNA118. Accordingly, the switch S1, the filter122, the LNA118, and the switch S2form one path between the nodes138and141. An electrically parallel path between the nodes138and141is shown to include a switch S3.

In the foregoing example ofFIG. 14, it is noted that relatively low loss can be realized in the bypass path with use of a single switch (S3) when bypassing of the LNA118is desired (e.g., during a Tx mode). It is also noted that relatively low loss can also be realized for a signal received through the diversity antenna (124) and being provided to the LNA118, with use of a single switch (S1) when the LNA118is being utilized (e.g., during a receive mode). It will be understood that other switching configurations can also be utilized.

FIG. 15Ashows an example of how the switches S1to S3can be operated when the LNA118is being utilized (e.g., during a receive mode). In such a mode, S1and S2before and after the LNA118can be closed, and S3can be opened. The example configuration ofFIG. 15Acan correspond to, for example, the DRx phase of the TDD operation described in reference toFIG. 13B. The same configuration ofFIG. 15Acan also facilitate the DRx operation ofFIG. 13A.

FIG. 15Bshows an example of how the switches S1to S3can be operated when the LNA118is being bypassed (e.g., during a Tx mode). In such a mode, S1and S2before and after the LNA118can be opened, and S3can be closed. The example configuration ofFIG. 15Bcan correspond to, for example, the Tx phase of the TDD operation (with the diversity antenna) described in reference toFIG. 13B.

In the context of the TDD operation (with the diversity antenna) ofFIG. 13B, the TDD switching actions (depicted as121and117) can correspond to switching between the configurations ofFIGS. 15A and 15B. As described herein, such TDD switching actions can be performed in cooperation with the switching action107of the switch circuit132inFIG. 13B.

FIG. 16shows yet another example TDD antenna routing system100that can be implemented with a reduced number of filters. In the example ofFIG. 16, the portion within the dashed boundary150can be similar to the example ofFIG. 12. Accordingly, various examples related to such a portion of the TDD antenna routing system100are described in reference toFIGS. 12 and 13.

In the example TDD antenna routing systems described in reference toFIGS. 8, 9, 12 and 13, one can see that other connections can be made between the Rx nodes and the antennas, in addition to the ones described, by appropriate operations of the various switching circuits. For example, and referring toFIGS. 9B and 13B, in which Tx operation is being achieved through the diversity antenna, the PRx amplification path from the main antenna can function as an amplification path for a DRx band. Similarly, the DRx amplification path from the diversity antenna can function as an amplification path for a PRx band. However, such swapping of PRx and DRx functionality results in the DRx signal being output to the PRx pin, and the PRx signal being output to the DRx pin.

In the example ofFIG. 16, a PRx/DRx switching circuit142is shown to be implemented relative to the PRx and DRx nodes. Such a switching circuit can be implemented in a cross-point configuration, and great flexibility can be achieved in possible connections between antennas (e.g., main and diversity) and Rx pins (e.g., PRx and DRx nodes). Such flexibility can include, for example, a DRx signal being output to the DRx pin even if it was obtained from the main antenna. Similarly, a PRx signal can be output to the PRx pin even if it was obtained from the diversity antenna.

Table 1 lists non-limiting examples of various connection configurations.

In Table 1, the first example configuration is a nominal configuration where a PRx signal originating from the main antenna and being output at the PRx pin is desired, with the DRx pin being OFF. Such a configuration can be achieved by, for example, TDD operation between Tx and PRx signal with the main antenna as described herein, and the DRx path being disabled. In the PRx/DRx switching circuit142, switch nodes142aand142bcan be connected, and all other switch nodes can be disconnected, to achieve such a configuration.

In Table 1, the second example configuration is a swapped configuration where a PRx signal originating from the diversity antenna and being output at the PRx pin is desired, with the DRx pin being OFF. Such a configuration can be achieved by, for example, TDD operation between Tx and PRx signal with the diversity antenna, and the PRx path being disabled. In the PRx/DRx switching circuit142, switch nodes142dand142acan be connected, and all other switch nodes can be disconnected, to achieve such a configuration.

In Table 1, the third example configuration is a nominal configuration where a DRx signal originating from the diversity antenna and being output at the DRx pin is desired, with the PRx pin being OFF. Such a configuration can be achieved by, for example, TDD operation of the DRx signal with the diversity antenna, and the PRx path being disabled. In the PRx/DRx switching circuit142, switch nodes142dand142ccan be connected, and all other switch nodes can be disconnected, to achieve such a configuration.

In Table 1, the fourth example configuration is a swapped configuration where a DRx signal originating from the main antenna and being output at the DRx pin is desired, with the PRx pin being OFF. Such a configuration can be achieved by, for example, TDD operation of the DRx signal with the main antenna, and the DRx path being disabled. In the PRx/DRx switching circuit142, switch nodes142band142ccan be connected, and all other switch nodes can be disconnected, to achieve such a configuration.

In Table 1, the fifth example configuration is a nominal configuration where a PRx signal originating from the main antenna and being output at the PRx pin, as well as a DRx signal originating from the diversity antenna and being output at the DRx pin, are desired. Such a configuration can be achieved by, for example, TDD operation between Tx and PRx signal with the main antenna, with switch nodes142band142abeing connected in the PRx/DRx switching circuit142; and the DRx path being operational to process a DRx signal, with switch nodes142dand142cbeing connected in the PRx/DRx switching circuit142.

In Table 1, the sixth example configuration is a swapped configuration where a PRx signal originating from the diversity antenna and being output at the PRx pin, as well as a DRx signal originating from the main antenna and being output at the DRx pin, are desired. Such a configuration can be achieved by, for example, TDD operation between Tx and PRx signal with the diversity antenna, with switch nodes142dand142abeing connected in the PRx/DRx switching circuit142; and the PRx path being operational to process a DRx signal, with switch nodes142band142cbeing connected in the PRx/DRx switching circuit142.

Among others, the foregoing examples in reference toFIG. 16and Table 1 show that a given Rx signal can be output to either of the PRx and DRx pins. Further, one or both of such Rx signals can be generated together. Thus, if a fixed pin assignment is desired (e.g., have a PRx signal be output only at the PRx pin, and a DRx signal be output only at the DRx pin), the example configuration ofFIG. 16can advantageously accommodate such design requirements.

In some implementations, an architecture, device and/or circuit having one or more features described herein can be included in an RF device such as a wireless device. Such an architecture, device and/or circuit can be implemented directly in the wireless device, in one or more modular forms as described herein, or in some combination thereof. In some embodiments, 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 modem configured to support machine type communications, a wireless access point, a wireless base station, etc. Although described in the context of wireless devices, it will be understood that one or more features of the present disclosure can also be implemented in other RF systems such as base stations.

FIG. 17depicts an example wireless device500having one or more advantageous features described herein. In some embodiments, such advantageous features can be implemented in a front-end (FE) module302, a diversity Rx module300, or any combination thereof. The FEM302is shown to include a power amplifier (PA) module512, an antenna switch module (ASM)514, and one or more low-noise amplifiers (LNAs)513.

As described herein, the diversity Rx module300can be configured so that its LNA is relatively close to a diversity antenna530which is preferably positioned relatively far from a main antenna520. Such a diversity module can be configured to provide, for example, bypassing functionalities associated with TDD operations involving Tx and signals received through the diversity antenna520.

PAs in the PA module512can receive their respective RF signals from a transceiver510that can be configured and operated to generate RF signals to be amplified and transmitted, and to process received signals. The transceiver510is shown to interact with a baseband sub-system508that is configured to provide conversion between data and/or voice signals suitable for a user and RF signals suitable for the transceiver510. The transceiver510is also shown to be connected to a power management component506that is configured to manage power for the operation of the wireless device500. Such power management can also control operations of the baseband sub-system508and other components of the wireless device500.

The baseband sub-system508is shown to be connected to a user interface502to facilitate various input and output of voice and/or data provided to and received from the user. The baseband sub-system508can also be connected to a memory504that 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.

A number of other wireless device configurations can utilize one or more features described herein. For example, a wireless device does not need to be a multi-band device. In another example, a wireless device 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 2. 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 2.