Same-aperture any-frequency simultaneous transmit and receive communication system

• US 10,651,886 B2
• Filed: 08/14/2019
• Issued: 05/12/2020
• Est. Priority Date: 07/30/2012
• Status: Active Grant

• Current Assignee: Photonic Systems Inc. (Photonics Systems Holding GmbH)
• Original Assignee: Photonic Systems Inc. (Photonics Systems Holding GmbH)
• Inventors: Cox, Charles H., Ackerman, Edward I.
• Primary Examiner(s): Tran, Tuan A
• Application Number:
  US16/540,584
• Publication Number:
  US 20190372616A1
• Time in Patent Office: 272 Days
• Field of Search: None
• CPC Class Codes: G01S 7/023 Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36
• CPC Class Codes: G01S 7/034 Duplexers switching devices for waveguides H01P1/10; transmit-receive switching in transceivers H04B1/44
• CPC Class Codes: G01S 7/038 Feedthrough nulling circuits
• CPC Class Codes: H04B 1/123 using adaptive balancing or compensation means adaptive filter circuits and algorithms H03H
• CPC Class Codes: H04B 1/48 in circuits for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter H04B1/46 takes precedence
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 1/56 with provision for simultaneous communication in two directions

Abstract

A same-aperture any-frequency simultaneously transmit and receive (STAR) system includes a signal connector having a first port electrically coupled to an antenna, a second port electrically coupled to a transmit signal path, and a third port electrically coupled to receive signal path. The signal connector passes a transmit signal in the transmit signal path to the antenna and a receive signal in the receive signal path. A signal isolator is positioned in the transmit signal path to remove a residual portion of the receive signal from transmit signal path. An output of the signal isolator provides a portion of the transmit signal with the residual portion of the receive signal removed. A signal differencing device having a first input electrically coupled to the output of the signal isolator and a second input electrically coupled to the third port of the signal connector subtracts a portion of the transmit signal in the receive signal path thereby providing a more accurate receive signal.

Claims

1. An any-frequency simultaneous transmit and receive (STAR) system, the system comprising:

a) a first antenna element that transmits a first RE transmit signal and that receives an RF receive signal;

b) a second antenna element that transmits a second RF transmit signal, wherein the first and second RF transmit signals and the RF receive signal occupy any RF frequency;

c) a signal connector configured to connect a path to and from the first antenna element, a path from an output of a transmit path and an input of a receive path;

d) a first transmit signal adjuster comprising an input connected to the transmit path;

e) a second transmit signal adjuster, wherein an output of the first transmit signal adjuster and an output of the second transmit signal adjuster are combined at an output of a combiner;

f) a signal differencing device comprising a first input connected to the receive path and a second input connected to the output of the combiner, the signal differencing device being configured to receive combined copies of the first and second RF transmit signals and to subtract them from the RE receive signal, thereby mitigating an effect of both the first and the second RF transmit signals on the RF receive signal; and

g) a signal processor comprising an input connected to an output of the signal differencing device, an output connected to an input of the first transmit signal adjuster and connected to an input of the second transmit signal adjuster and connected to a receive output, the signal processor being configured to receive attenuated combined copies of the first and second RF transmit signals and to determine a complex value of at least one of the first and second RF transmit signals so as to minimize at least one of residual first and second RF transmit signals in the RF receive signal at the receive output.

2. The system of claim 1 wherein the signal connector provides a matched impedance for at least one of the path from and to the first antenna element, the path from the output of the transmit path, and the path to the input of the receive path.

3. The system of claim 1 wherein the signal connector provides a higher impedance at the path from the output of the transmit path than at either of the path to and from the first antenna element and the path from the output of the transmit path.

4. The system of claim 1 wherein the signal connector comprises a fast switch.

5. The system of claim 1 wherein signal differencing device comprises an active differencing device.

6. The system of claim 1 wherein the signal differencing device comprises a passive differencing device.

7. The system of claim 1 wherein the signal differencing device comprises a photonic differencing device.

8. The system of claim 1 wherein an algorithm executed by the signal processor correlates a copy of at least one of the first and second RF transmit signal with the output of the differencing device and generates a more accurate representation of the RF receive signal.

9. The system of claim 1 wherein the signal processor comprises an analog signal processor.

10. The system of claim 1 wherein the signal processor comprises a digital signal processor.

11. The system of claim 1 wherein the first and second RF transmit signal comprise a same transmit signal.

12. The system of claim 1 wherein the first and second RF transmit signal comprise a different transmit signal.

13. The system of claim 1 wherein the system comprises a microwave system.