Wireless device with adaptively-tunable electrically-small antennas

1. A communication device, comprising:

a transmitter (TX), which is configured to produce a TX signal for transmission on a TX frequency band;

a receiver (RX), which is configured to process an RX signal received on an RX frequency band that is different from the TX frequency band;

an adaptively-tunable Transmit/Receive (TX/RX) Electrically-Small Antenna (ESA), configured to transmit the TX signal on the TX frequency band and to receive the RX signal on the RX frequency band;

an adaptively-tunable Receive-only (RX) ESA, configured to receive the RX signal on the RX frequency band; and

a control unit, which is configured to:

adaptively tune a narrowband response of the TX/RX ESA to the TX frequency band, both while transmitting on the TX band and while receiving on the RX band, such that the TX/RX ESA has degraded reception performance relative to the RX ESA in the RX band; and

while receiving on the RX band, to apply diversity reception to the RX signal received by the TX/RX ESA and the RX-only ESA, and to reduce an impact of the degraded reception performance of the TX/RX ESA by assigning the RX ESA to serve as a primary antenna and assigning the TX/RX ESA to serve as a secondary antenna.

2. The device according to claim 1 , wherein at least one of the adaptively-tunable ESAs has an instantaneous bandwidth that corresponds to the instantaneous bandwidth of the RX or TX signal.

3. The device according to claim 1 , wherein the control unit is configured to tune at least one of the adaptively-tunable ESAs to match an actual frequency of the RX or TX signal.

4. The device according to claim 1 , wherein the control unit is configured to tune the adaptively-tunable TX/RX ESA so as to balance a performance of the adaptively-tunable TX/RX ESA over the RX and TX bands.

5. The device according to claim 1 , wherein at least one of the adaptively-tunable ESAs comprises an impedance matching network, and wherein the control unit is configured to adaptively tune the one of the adaptively-tunable ESAs by adjusting the impedance matching network.

6. The device according to claim 1 , wherein at least one of the adaptively-tunable ESAs comprises an aperture-tuning element, and wherein the control unit is configured to adaptively tune the one of the adaptively-tunable ESAs by adjusting the aperture-tuning element.

7. The device according to claim 1 , wherein the control unit is configured to adaptively tune at least one of the adaptively-tunable ESAs by adaptively connecting or disconnecting one or more elements of the one of the adaptively-tunable ESAs.

8. The device according to claim 1 , wherein the control unit is configured to adaptively tune at least one of the adaptively-tunable ESAs based on at least one metric selected from a group of metrics consisting of:

a Voltage Standing Wave Ratio (VSWR) of the one of the adaptively-tunable ESAs;

a property of the RX signal;

a property of the TX signal; and

an indication from a detector or sensor in the device.

9. The device according to claim 1 , wherein the TX and RX are configured to transmit the TX signals and receive the RX signals using Frequency-Division Duplex (FDD) or Half-duplex FDD (HFDD).

10. A method for communication, comprising:

transmitting a transmit (TX) signal on a TX frequency band via an adaptively-tunable Transmit/Receive (TX/RX) Electrically-Small Antenna (ESA), and receiving a receive (RX) signal on an RX frequency band, different from the TX frequency band, via the adaptively-tunable TX/RX ESA and via an adaptively-tunable Receive-only (RX) ESA;

adaptively tuning a narrowband response of the TX/RX ESA to the TX frequency band, both while transmitting on the TX band and while receiving on the RX band, such that the TX/RX ESA has degraded reception performance relative to the RX ESA in the RX band; and

while receiving on the RX band, applying diversity reception to the RX signal received by the TX/RX ESA and the RX-only ESA, and reducing an impact of the degraded reception performance of the TX/RX ESA by assigning the RX ESA to serve as a primary antenna and assigning the TX/RX ESA to serve as a secondary antenna.

11. The method according to claim 10 , wherein at least one of the adaptively-tunable ESAs has an instantaneous bandwidth that corresponds to the instantaneous bandwidth of the RX or TX signal.

12. The method according to claim 10 , and comprising tuning at least one of the adaptively-tunable ESAs to match an actual frequency of the RX or TX signal.

13. The method according to claim 10 , wherein adaptively tuning the response comprises tuning the adaptively-tunable TX/RX ESA so as to balance a performance of the adaptively-tunable TX/RX ESA over the RX and TX bands.

14. The method according to claim 10 , wherein adaptively tuning the response comprises adjusting an impedance matching network of at least one of the adaptively-tunable ESAs.

15. The method according to claim 10 , wherein adaptively tuning the response comprises adjusting an aperture-tuning element of at least one of the adaptively-tunable ESAs.

16. The method according to claim 10 , wherein adaptively tuning the response comprises connecting or disconnecting one or more elements of at least one of the adaptively-tunable ESAs.

17. The method according to claim 10 , wherein adaptively tuning the response comprises tuning at least one of the adaptively-tunable ESAs based on at least one metric selected from a group of metrics consisting of:

a Voltage Standing Wave Ratio (VSWR) of the one of the adaptively-tunable ESAs;

a property of the RX signal;

a property of the TX signal; and

an indication from a detector or sensor.

18. The method according to claim 10 , wherein transmitting the TX signals and receiving the RX signals comprises applying Frequency-Division Duplex (FDD) or Half-duplex FDD (HFDD).