Phased array system using baseband phase shifting

• US 8,013,791 B1
• Filed: 07/30/2008
• Issued: 09/06/2011
• Est. Priority Date: 07/30/2008
• Status: Expired due to Fees

• Current Assignee: Iowa State University Research Foundation Incorporated (Iowa State University)
• Original Assignee: Iowa State University Research Foundation Incorporated (Iowa State University)
• Inventors: Sekar, Saalini, Wanner, Shannon, Fu, Hsin-Jan, Weber, Robert J.
• Primary Examiner(s): PHAN, DAO LINDA
• Application Number:
  US12/182,678
• Time in Patent Office: 1,133 Days
• Field of Search: 342/157, 342/368, 342/372, 342/373, 455/276.1
• US Class Current: 342/372
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
• CPC Class Codes: H01Q 3/38 the phase-shifters being digital

Abstract

A method of spatial control of a phased array system having a plurality of antenna elements is provided. The method includes providing a baseband signal, baseband phase shifting the baseband signal to provide a plurality of baseband shifted signals for controlling phase of each of the plurality of antenna elements, upconverting each of the baseband shifted signals to a radio frequency signal, and applying each of the radio frequency signals to the plurality of antenna elements to thereby provide for spatial control of the phased array system. A hardware architecture for a phased array system is also provided.

Claims

1. A method of spatial control of a phased array system having a plurality of antenna elements, the method comprising:

providing a baseband signal;

baseband phase shifting the baseband signal to provide a plurality of baseband shifted signals for controlling phase of each of the plurality of antenna elements;

upconverting each of the baseband shifted signals to a radio frequency signal;

applying each of the radio frequency signals to the plurality of antenna elements to thereby provide for the spatial control of the phased array system.

2. The method of claim 1 wherein the baseband phase shifting is performed using active phase shifters.

3. The method of claim 1 further comprising controlling amplitude of each of the radio frequency signals.

4. The method of claim 1 further comprising transmitting each of the radio frequency signals with the phased array antenna system.

5. The method of claim 2 wherein each of the active phase shifters comprises a shift register.

6. The method of claim 2 wherein each of the active phase shifters further comprises a phase locked loop.

7. The method of claim 6 wherein each of the active phase shifters comprises an adjustable amplifier.

8. The method of claim 7 wherein each of the active phase shifters further comprises an offset phase locked loop.

9. The method of claim 6 wherein the phase locked loop is adapted for receiving a phase aid to increase speed.

10. The method of claim 1 wherein the radio frequency signal being greater than 2 GHz.

11. A phased array system, comprising:

a plurality of integrated antenna elements;

a phase adjusting circuit comprising active phase shifters adapted to provide baseband phase shifts in a baseband signal, the active phase shifters comprising phase locked loops configured to receive a phase aid to increase speed;

an upconverter circuit operatively connected between the phase adjusting circuit and the plurality of integrated antenna elements and adapted to upconvert the baseband signal to a radio frequency signal.

12. The phased array system of claim 11 wherein the phase locked loops comprise an offset phase locked loop.

13. The phased array system of claim 11 wherein the radio frequency signal being greater than 2 GHz.

14. The phased array system of claim 11 further comprising a diplexer operatively connected to the plurality of integrated antenna elements and wherein the upconverter circuit being operatively connected to the diplexer.

15. The phased array system of claim 14 further comprising a downconverter circuit operatively connected to the diplexer and a phase detecting circuit operatively connected to the downconverter circuit.

16. The phased array system of claim 15 further comprising an output amplifier between the upconverter circuit and the diplexer and a low noise amplifier between the diplexer and the downconverter circuit.

17. A method of spatial control of a phased array system having a plurality of antenna elements, the method comprising:

providing a baseband signal;

baseband phase shifting the baseband signal, the step of baseband phase shifting comprising (a) using a variable phase shifter to provide a plurality of baseband shifted signals for controlling phase of each of the plurality of antenna elements, wherein each of the variable phase shifters comprises a phased lock loop, (b) providing a phase aid to each of the phased lock loops;

upconverting each of the baseband shifted signals to a radio frequency signal;

applying each of the radio frequency signals to the plurality of antenna elements to thereby provide for the spatial control of the phased array system.

18. A phased array system, comprising:

a plurality of integrated antenna elements;

for each of the integrated antenna elements,

(a) a serial in, serial out shift register electrically connected to receive as input a reference clock signal and a phased lock loop feedback signal,

(b) a multiplexer electrically connected to the shift register,

(c) a register electrically connected to the multiplexer,

(d) a phased lock loop electrically connected to the multiplexer, an output of the phase lock loop electrically connected to the shift register to provide the phased lock loop feedback signal,

(e) an amplifier electrically connected to the output of each of the phased lock loops,

(f) an output of the amplifier electrically connected as input to one of the integrated antenna elements.

19. The phased arrays system of claim 18 further comprising a phase aid input electrically connected to the phased lock loop for each of the integrated antenna elements.