Same-Aperture Any-Frequency Simultaneous Transit And Receive Communication System

• US 20150207537A1
• Filed: 07/30/2013
• Published: 07/23/2015
• 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.
• Granted Patent: US 10,374,656 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04L 5/1461 Suppression of signals in the return path, i.e. bidirectional control circuits

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. -20. (canceled)

21. A same-aperture any-frequency simultaneously transmit and receive (STAR) system, the STAR system comprising:

a) 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 a receive signal path, the signal connector passing a transmit signal in the transmit signal path to the antenna and passing a receive signal in the receive signal path;

b) a signal isolator positioned in the transmit signal path that removes a residual portion of the receive signal from transmit signal path, an output of the signal isolator providing a portion of the transmit signal with the residual portion of the receive signal removed;

c) 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, the signal differencing device subtracting a portion of the transmit signal in the receive signal path, thereby providing a copy of the receive signal at an output of the signal differencing device; and

d) an adaptive signal processor having a first input electrically coupled to the output of the signal differencing device and a second input electrically coupled to the transmit signal path, the adaptive signal processor processing the copy of the receive signal so as to reduce a residual transmit signal in the receive signal path.

22. The system of claim 21 wherein the adaptive signal processor comprises an analog signal processor.

23. The system of claim 21 wherein the adaptive signal processor comprises a digital signal processor.

24. The system of claim 21 wherein the adaptive signal processor processes the copy of the receive signal so as to minimize the residual transmit signal in the receive signal path.

25. The system of claim 21 wherein the adaptive signal processor generates multiple delayed copies of the transmit signal.

26. The system of claim 21 wherein the processing performed by the adaptive signal processor comprises correlating a copy of the transmit signal with the output of the signal differencing device and generating a more accurate representation of the receive signal at the output of the signal differencing device.

27. The system of claim 21 further comprising a transmit signal adjusting circuit having a first input electrically coupled to an output of the adaptive signal processor and a second input electrically coupled to the output of the signal isolator, and an output that is electrically coupled to the first input of the signal differencing device, the transmit signal adjusting circuit setting a complex value of the transmit signal.

28. The system of claim 27 wherein the setting of the complex value of the transmit signal is determined from the transmit signal at RF frequencies.

29. The system of claim 27 wherein the setting of the complex value of the transmit signal is determined from the transmit signal at down-converted IF frequencies.

30. The system of claim 27 wherein the setting of the complex value of the transmit signal comprises adjusting a magnitude and a phase of the transmit signal.

31. The system of claim 27 wherein the setting of the complex value of the transmit signal comprises adjusting an in-phase component and an in-quadrature component of the transmit signal.

32. The system of claim 21 wherein the signal connector provides a matched impedance for at least one of the first, second, and third ports.

33. The system of claim 21 wherein the signal connector provides a higher impedance at the second port than at either the first and the second ports.

34. The system of claim 21 wherein the signal connector comprises a fast switch.

35. The system of claim 21 wherein the signal differencing device comprises an active differencing device.

36. The system of claim 21 wherein the signal differencing device comprises a passive differencing device.

37. The system of claim 21 wherein the signal differencing device comprises a photonic differencing device.

38. The system of claim 21 wherein the signal isolator comprises an electronic voltage-source-based isolator.

39. The system of claim 21 wherein the signal isolator comprises a current-source-based signal isolator.

40. The system of claim 21 wherein the signal isolator comprises a non-reciprocal RF isolator.

41. The system of claim 21 wherein the signal isolator comprises a photonic isolator.

42. The system of claim 21 further comprising a feedback system having an input coupled to the output of the signal differencing device and an output coupled to the first input of the signal differencing device, the feedback system generating a signal that when added to the portion of the transmit signal from the signal isolator more fully subtracts the transmit signal from the receive signal.

43. The system of claim 42 wherein the feedback system generates at the output a desired complex value of the transmit signal that when added the portion of the transmit signal from the isolator more fully subtracts the transmit signal from the receive path.

44. A method of same-aperture any-frequency simultaneously transmitting and receiving, the method comprising:

a) connecting a receive signal from an antenna with a transmit signal from a transmit signal path so that the receive signal is passed to a receive signal path and a transmit signal is passed to an antenna;

b) isolating a portion of the transmit signal from a residual receive signal in the transmit signal path;

c) subtracting the isolated portion of the transmit signal in the transmit signal path from the receive signal in the receive signal path, thereby removing a residual portion of the transmitted signal from the receive signal path making a more accurate representation of the receive signal; and

d) processing the copy of the receive signal so as to reduce a residual transmit signal in the receive signal path.

45. The method of claim 44 wherein the processing the copy of the receive signal minimizes the residual transmit signal in the receive signal path.

46. The method of claim 44 wherein the processing the copy of the receive signal so as to reduce a residual transmit signal in the receive signal path comprises correlation.

47. The method of claim 44 further comprising correlating a copy of the transmit signal with the subtracted signal to generate a more accurate representation of the receive signal.

48. The method of claim 44 further comprising setting a complex value of the transmit signal.

49. The system of claim 48 wherein the setting of the complex value of the transmit signal is determined from the transmit signal at RF frequencies.

50. The system of claim 48 wherein the setting of the complex value of the transmit signal is determined from the transmit signal at down-converted IF frequencies.

51. The system of claim 48 wherein the setting of the complex value of the transmit signal comprises adjusting a magnitude and a phase of the transmit signal.

52. The system of claim 48 wherein the setting of the complex value of the transmit signal comprises adjusting an in-phase component and an in-quadrature component of the transmit signal.

53. The method of claim 44 wherein the isolating is performed non-reciprocally.

54. A same-aperture any-frequency simultaneously transmit and receive (STAR) system, the system comprising:

a) means for connecting a receive signal with a transmit signal so that the receive signal is passed to a receive signal path and the transmit signal is passed from a transmit signal path to an antenna;

b) means for isolating a portion of the transmit signal from a residual receive signal component in the transmit signal path;

c) means for subtracting the isolated portion of the transmit signal from the receive signal in the receive signal path, thereby removing a residual portion of the transmitted signal from the receive signal path making a more accurate representation of the receive signal; and

d) means for processing the copy of the receive signal with an adaptive signal processor so as to reduce a residual transmit signal in the receive signal path.