Hybrid-based cancellation in presence of antenna mismatch

• US 10,615,949 B2
• Filed: 02/17/2015
• Issued: 04/07/2020
• Est. Priority Date: 02/14/2014
• Status: Active Grant

• Current Assignee: University of Southern California
• Original Assignee: University of Southern California
• Inventors: Goel, Ankush, Analui, Behnam, Hashemi, Hossein
• Primary Examiner(s): Divito, Walter J
• Application Number:
  US14/624,289
• Publication Number:
  US 20150236842A1
• Time in Patent Office: 1,876 Days
• CPC Class Codes: H03H 7/463 Duplexers
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 1/58 Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa
• CPC Class Codes: H04L 5/1461 Suppression of signals in the return path, i.e. bidirectional control circuits

Abstract

A multi-port hybrid-based cancellation network may include a first and second hybrid coupler, and a first and second two-port network. The second hybrid coupler may be distinct from the first hybrid coupler. The first two-port network may include a first filter connected between the first and the second hybrid couplers. The second two-port network may include a second filter that is distinct from but essentially the same as the first filter connected between the first and the second hybrid couplers. Other circuitry components may be connected to one of the ports of multi-port hybrid-based cancellation network. These other circuitry components may have a configuration that increases or maximizes signal isolation between at least two of the ports of the multi-port hybrid-based cancellation network.

Claims

1. A multi-port hybrid-based cancellation network comprising

a first hybrid coupler having a first port, a second port, a third port, and a fourth port;

a second hybrid coupler that is distinct from the first hybrid coupler, the second hybrid coupler having a fifth port, a sixth port, a seventh port, and an eighth port;

a first two-port network connected between the first port of the first hybrid coupler and the fifth port of the second hybrid coupler;

a second two-port network that is distinct from, but essentially similar to the first two-port network, connected between the second port of the first hybrid coupler and the sixth port of the second hybrid coupler;

a third two-port network that is distinct from the first and the second two-port networks connected to the third port of the first hybrid coupler;

an antenna having an antenna impedance connected to the fourth port of the first hybrid coupler; and

a load having a load impedance connected to the eighth port of the second hybrid coupler, the load having a load reflection coefficient matched to the antenna impedance with a phase that is 180°

different than that of the antenna impedance at bandpass frequencies of the first two-port network and the second two-port network.

2. The multi-port hybrid-based cancellation network of claim 1 further comprising one or more other circuit components, at least one of which is connected to at least one port of one of the first hybrid coupler, the second hybrid coupler, the first two-port network, the second two-port network, and the third two-port network, in a configuration that:

reduce a signal reflection coefficient in at least one of the ports of the multi-port hybrid-based cancellation network;

or

increase signal isolation between at least two of the ports of the multi-port hybrid-based cancellation network.

3. The multi-port hybrid-based cancellation network of claim 2 wherein the one or more other circuit components have a tunable transfer function.

4. The multi-port hybrid-based cancellation network of claim 3 wherein the tunable transfer function can be adjusted to minimize the signal reflection coefficient or maximize signal isolation.

5. The multi-port hybrid-based cancellation network of claim 4 wherein the tunable transfer function is automatically adjusted by one or more additional circuitry components.

6. The multi-port hybrid-based cancellation network of claim 3 wherein the tunable transfer function can be adjusted based on a sensed condition.

7. The multi-port hybrid-based cancellation network of claim 6 wherein the sensed condition includes noise.

8. The multi-port hybrid-based cancellation network of claim 2 wherein the one or more other circuit components include one or more variable or fixed attenuators.

9. The multi-port hybrid-based cancellation network of claim 2 wherein the one or more other circuit components include one or more variable or fixed phase shifters.

10. The multi-port hybrid-based cancellation network of claim 2 wherein the one or more other circuit components include one or more variable or fixed delay elements.

11. The multi-port hybrid-based cancellation network of claim 2 wherein the one or more other circuit components include an impedance matching network.

12. The multi-port hybrid-based cancellation network of claim 2 wherein the one or more other circuit components reduce the signal reflection coefficient.

13. The multi-port hybrid-based cancellation network of claim 12 wherein at least one of the first hybrid coupler, the second hybrid coupler, the first two-port network, the second two-port network, the third two-port network, or the one or more other circuit components can be adjusted to reduce the signal reflection coefficient.

14. The multi-port hybrid-based cancellation network of claim 2 wherein the one or more other circuit components increase signal isolation.

15. The multi-port hybrid-based cancellation network of claim 14 wherein at least one of the first hybrid coupler, the second hybrid coupler, the first two-port network, the second two-port network, the third two-port network, or the one or more other circuit components can be adjusted to increase signal isolation.

16. The multi-port hybrid-based cancellation network of claim 1 wherein at least one of the first two-port network, the second two-port network, the third two-port network, is tunable.

17. The multi-port hybrid-based cancellation network of claim 1 wherein the multi-port hybrid-based cancellation network operates effectively within multiple frequency bands.

18. The multi-port hybrid-based cancellation network of claim 2 wherein at least some of the one or more other circuit components, the first hybrid coupler, the second hybrid coupler, the first two-port network, the second two-port network, and the third two-port network are part of a single integrated circuit.

19. The multi-port hybrid-based cancellation network of claim 2 wherein at least some of the one or more other circuit components, the first hybrid coupler, the second hybrid coupler, the first two-port network, the second two-port network, and the third two-port network are part of a single substrate.

20. The multi-port hybrid-based cancellation network of claim 2 wherein the multi-port hybrid-based cancellation network includes a port having a configuration that is appropriate to connect to a transmitter, a port having a configuration that is appropriate to connect to a receiver, and a port having a configuration that is appropriate to connect to an antenna.

21. The multi-port hybrid-based cancellation network of claim 20 wherein the one or more other circuit components reduce the signal reflection coefficient of the port that is appropriate to connect to the antenna.

22. The multi-port hybrid-based cancellation network of claim 20 wherein the one or more other circuit components increase signal isolation between the port that is appropriate to connect to the receiver and the port that is appropriate to connect to the transmitter.

23. The multi-port hybrid-based cancellation network of claim 1 wherein all or some of the components are integrated with a receiver, a transmitter, or a transceiver.

24. The multi-port hybrid-based cancellation network of claim 1 wherein the load is variable.

25. The multi-port hybrid-based cancellation network of claim 2 wherein one or more of the one or more other circuit components is connected between the first port of the first hybrid coupler and the first two-port network.

26. The multi-port hybrid-based cancellation network of claim 25 wherein one or more of the one or more other circuit components include tunable phase shifters, tunable attenuators, tunable delay elements, or combinations thereof.

27. The multi-port hybrid-based cancellation network of claim 25 further comprising a monitoring block and a calibration block, the monitoring block being connected to the fourth port of the first hybrid coupler and the seventh port of the second hybrid coupler and providing an input to the calibration block, the calibration block providing values to automatically set the one or more of the one or more other circuit components.

28. The multi-port hybrid-based cancellation network of claim 2 wherein one or more of the one or more other circuit components have a value that varies as a function of changes in an impedance that is presented to one of the ports of the multi-port hybrid-based cancellation network.

29. The multi-port hybrid-based cancellation network of claim 1 further comprising a monitoring block and a calibration circuitry, the monitoring block being connected to the fourth port of the first hybrid coupler and the seventh port of the second hybrid coupler and providing an input to the calibration block, the calibration circuitry adjusting the load impedance.

30. The multi-port hybrid-based cancellation network of claim 1 wherein reflected signals from the load cancel reflections from the antenna when they combine at the seventh port.

31. The multi-port hybrid-based cancellation network of claim 1 further comprising:

a first circuit component having a tunable transfer function interposed between the first two-port network and the first port of the first hybrid coupler; and

a second circuit component having a tunable transfer function interposed between the second two-port network and the second port of the first hybrid coupler.

32. The multi-port hybrid-based cancellation network of claim 31 further comprising a monitoring block and a calibration circuitry, the monitoring block being connected to the fourth port of the first hybrid coupler and the seventh port of the second hybrid coupler and providing an input to the calibration block, the calibration circuitry adjusting the load impedance, the first circuit component having a tunable transfer function, and the second circuit component having a tunable transfer function.