Multicode aperture transmitter/receiver

• US 8,509,205 B2
• Filed: 06/05/2008
• Issued: 08/13/2013
• Est. Priority Date: 06/05/2008
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Jain, Atul, Whelan, David A.
• Primary Examiner(s): Moore, Ian N
• Assistant Examiner(s): Huynh, Dung B
• Application Number:
  US12/133,959
• Publication Number:
  US 20090303126A1
• Time in Patent Office: 1,895 Days
• Field of Search: None
• US Class Current: 370/342
• CPC Class Codes: G01S 13/003 Bistatic radar systems; Multistatic radar systems
• CPC Class Codes: G01S 13/288 phase modulated
• CPC Class Codes: G01S 2013/0254 Active array antenna
• CPC Class Codes: G01S 2013/0281 LPI, Low Probability of Intercept radar
• CPC Class Codes: H04B 7/0678 using different spreading codes between antennas code allocation H04J13/16
• CPC Class Codes: H04B 7/0837 using pre-detection combining H04B7/0868 takes precedence

Abstract

Systems and methods according to one or more embodiments provide for a multicode transmitter/receiver that acts like a high power array when a correlated receiver is used, but acts as a collection of small low gain transmitters when an uncorrelated receiver is used. In one embodiment, a method of transmitting and receiving signals comprises splitting a signal into more than one portion for feeding the signal into separate elements of an array; coding each portion of the signal for transmission through each separate element of the array with a different code respectively; transmitting each coded portion of the signal through a corresponding separate element of the array; receiving the coded portions of the signal by at least one element on a receiver side; decoding the coded portions of the signal; and adding decoded portions of the signal to form a complete received signal.

Claims

1. A method of transmitting and receiving signals, the method comprising:

splitting a signal into two or more low power portions for feeding the signal into separate elements of an array;

coding each low power portion of the signal for transmission through each separate element of the array with a different code respectively, wherein the coding comprises convolving the low power portion of the signal with the respective different code individually corresponding to the respective separate element;

transmitting each coded portion of the signal through a corresponding separate element of the array;

receiving the coded portions of the signal by at least one element on a receiver side, wherein receiving the coded portions of the signals further comprises receiving return signals at the at least one element on the receiver side upon illuminating a target object;

decoding the coded portions of the signal; and

adding decoded portions of the signal with a correlated receiver to form a complete received signal, wherein the array acts like a high power transmitter array when the correlated receiver is used, but acts as a collection of small transmitter arrays when an uncorrelated receiver is used.

2. The method of claim 1, wherein the array further comprises an active antenna array or a conventional phased array.

3. The method of claim 1, wherein the splitting the signal further comprises using a corporate feed system.

4. The method of claim 1, wherein the at least one element on the receiver side further comprises multiple separate receiver elements wherein each separate receiver element receives all the coded portions of the signal.

5. The method of claim 1, wherein the coding each portion of the signal for transmission through each separate element further comprises coding each portion of the signal respectively with coded waveforms that are orthogonal to each other.

6. The method of claim 1, wherein the array further comprises an ultrasound, an optical or an infrared transmitter/receiver array.

7. The method of claim 2, further comprising using the active antenna array in a communications system or in a radar system.

8. The method of claim 7, wherein the receiving the coded portions of the signal by the at least one element on the receiver side of the radar system further comprises receiving the coded portions of the signal reflected from a target object by separate receiver elements at the active antenna array.

9. The method of claim 7, wherein the at least one element on a receiver side in the communications system is located externally with an external receiver.

10. The method of claim 1, wherein the decoding comprises convolving the coded portions of the signal with a complex conjugate of a sum of the different codes.

19. The array of claim 10, wherein the different codes further comprise coded waveforms that are orthogonal to each other.

20. The array of claim 19, wherein the different codes are supplied by a waveform generator.

11. A multicode array for receiving and transmitting a signal comprising:

a feed adapted to receive and split the signal into low power signals;

individual elements at a transmitter side of the multicode array wherein each low power signal is coded with different codes respectively and transmitted through each individual element of the multicode array, wherein the coding with different codes comprises convolving each low power signal with the different code individually corresponding to the respective individual element;

at least one element at a receiver side wherein the at least one element receives all the low power signals, wherein receiving the coded, low power signals further comprises receiving return signals at the multicode array upon illuminating a target object; and

a correlated receiver adapted to add decoded low power signals to form a complete received signal, wherein the multicode array acts like a high power transmitter array when the correlated receiver is used, but acts as a collection of small transmitter arrays when an uncorrelated receiver is used.

12. The array of claim 11, wherein the at least one element at the receiver side further comprises multiple separate receiver elements.

13. The array of claim 11, further comprising control electronics and a power conditioning block.

14. The array of claim 11, further comprising an active antenna array or a conventional phased array.

15. The array of claim 14, wherein the active antenna array is adapted for use in a communications system or in a radar system.

16. The array of claim 15, wherein the at least one element at the receiver side in the communications system is located externally with an external receiver.

17. The array of claim 14, wherein the at least one element at the receiver side in the radar system is part of the active antenna array itself.

18. The array of claim 11, further comprising an ultrasound, an optical or an infrared receiver/transmitter array.

21. The array of claim 11, further comprising a correlator located external to the receiver, wherein the correlator is adapted to decode the low power signals received from the at least one element at the receiver side and to supply decoded low power signals to the receiver.

22. The array of claim 11, further comprising at least one transmit/receive (T/R) module.

23. The array of claim 22, wherein the different codes are built-in within the at least one module.

24. The array of claim 11, wherein the receiver further comprises a memory for storing coded waveforms for decoding the low power signals received from the at least one element at the receiver side.

25. A method of transmitting and receiving signals in a high power radar system, the method comprising:

splitting a signal into low power signals;

coding the low power signals with different codes, wherein the coding comprises convolving each low power signal with the different code individually corresponding to a respective separate element of an active antenna array;

transmitting the coded low power signals through the individual elements of the active antenna array;

receiving the coded low power signals by at least one individual receiver element, wherein receiving the coded low power signals further comprises receiving return signals at the active antenna array upon illuminating a target object;

decoding the coded low power signals; and

adding the decoded signals with a correlated receiver to form a complete received signal,

wherein the active antenna array acts like a high power transmitter array when the correlated receiver is used, but acts as a collection of small transmitter arrays when an uncorrelated receiver is used.

26. The method of claim 25, comprising an active antenna array for a communications system wherein the correlated receiver is located externally.

27. The method of claim 25, comprising an ultrasound system wherein the array comprises an ultrasound, an optical or an infrared transmitter/receiver array.

28. The method of claim 25 wherein the coded low power signals comprise waveforms that are orthogonal to each other.

29. A method of receiving signals, the method comprising:

receiving coded, low power portions of a signal by at least one receiver element wherein each portion of the signal is coded with a different code respectively, wherein the coding comprises convolving the portion of the signal with the different code individually corresponding to the respective portion of the signal, and wherein receiving the coded, low power portions of the signal further comprises receiving return signals at the at least one receiver element upon illuminating a target object;

decoding the coded portions of the signal; and

adding decoded portions of the signal with a correlated receiver to form a complete received signal, wherein the signal appears to come from a high power transmitter array when the correlated receiver is used, but appears to come from a collection of small transmitter arrays when an uncorrelated receiver is used.

30. The method of claim 29 further comprising transmitting each coded portion of the signal through separate transmitter elements of an array.

31. A multicode array comprising:

a plurality of modules adapted to process and code low power portions of a signal, wherein each coded, low power portion of the signal comprises a low power portion of the signal convolved with a different code individually corresponding to the respective low power portion of the signal; and

a correlated receiver comprising at least one correlated receiver element wherein the at least one correlated receiver element receives and decodes the differently coded, low power portions of the signal wherein;

receiving the differently coded portions of the signal further comprises receiving return signals at the at least one correlated receiver element upon illuminating a target object;

the correlated receiver is adapted to add decoded portions of the signal to form a complete received signal; and

the multicode array acts like a high power transmitter array when the correlated receiver is used, but acts as a collection of small transmitter arrays when an uncorrelated receiver is used.

32. The array of claim 31 further comprising individual transmitter elements coupled to each module wherein each portion of the signal is coded with a different code that is orthogonal to each code for a different portion of the signal and transmitted through each individual transmitter element of the multicode array.