Variable-Phase Ring-Oscillator Arrays, Architectures, and Related Methods

• US 20070290930A1
• Filed: 05/14/2007
• Published: 12/20/2007
• Est. Priority Date: 05/12/2006
• Status: Active Grant

• Current Assignee: University of Southern California
• Original Assignee: University of Southern California
• Inventors: Krishnaswamy, Harish, Hashemi, Hossein
• Granted Patent: US 7,840,199 B2
• Time in Patent Office: Days
• US Class Current: 343/700.0MS
• CPC Class Codes: G01S 2013/0254 Active array antenna
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H03B 27/00 Generation of oscillations providing a plurality of outputs of the same frequency but differing in phase, other than merely two anti-phase outputs
• CPC Class Codes: H03L 7/087 using at least two phase detectors or a frequency and phase detector in the loop
• CPC Class Codes: H03L 7/0995 the oscillator comprising a ring oscillator
• CPC Class Codes: H03L 7/22 using more than one loop

Abstract

Embodiments of the present disclosure allow for a linear phase progression between adjacent elements in array by providing a symmetric ring configuration of tuned amplifiers and a single phase shifter. This ring topology is coupled to a single phase locked loop (“PLL”) that allows for direct modulation and demodulation of arbitrary waveforms without using RF up/down converting mixers. In addition, the PLL distributes the transmit waveforms to all antenna elements in the transmit mode and combines the received waveforms in the receive mode without any complicated power distribution network.

Claims

1. A variable-phase ring-oscillator circuit comprising:

a plurality of tuned amplifiers tuned amplifier configured as a ring in series;

a first phase shifter coupled to the plurality of tuned amplifiers tuned amplifier, wherein the first phase shifter provides a phase delay between each pair of successive tuned oscillators; and

a phase-locked loop connected to the ring.

2. The variable-phase ring-oscillator circuit of claim 1, further comprising a second phase shifter connected to the ring.

3. The variable-phase ring-oscillator of claim 1, wherein the phase-locked loop includes a frequency divider.

4. The variable-phase ring-oscillator of claim 1, wherein the phase-locked loop includes a frequency phase detector.

5. The variable-phase ring-oscillator of claim 1, wherein the phase-locked loop includes a charge pump.

6. The variable-phase ring-oscillator of claim 1, wherein the phase-locked loop includes a loop filter.

7. The variable-phase ring-oscillator circuit of claim 1, further comprising a plurality of antennas coupled to the plurality of tuned amplifiers, wherein the plurality of antennas are configured and arranged as an array.

8. The variable-phase ring-oscillator circuit of claim 1, wherein the plurality of tunable amplifiers and plurality of antennas are configured on a semiconductor substrate.

9. The variable-phase ring oscillator of claim 2, wherein the phase-locked loop in disposed on a semiconductor substrate.

10. The variable phase ring oscillator circuit of claim 1, wherein the plurality of tuned amplifiers are configured in a two dimensional m×

n array.

11. The variable phase ring oscillator circuit of claim 10, further comprising m first phase shifter, each coupled to a separate ring in the m dimension of the m×

n array and n second phase shifter, each coupled to a separate ring in the m×

n array.

12. A phased array comprising:

a plurality of tuned amplifiers configured in series in a ring;

a first phase shifter inserted in the ring coupled to the plurality of tuned amplifiers, wherein the first phase delay structure provides a phase delay between each pair of successive tuned amplifier;

a phase-locked loop connected to the ring; and

a plurality of antennas connected to the ring.

13. The phased array of claim 12, wherein the plurality of tuned amplifiers are disposed on a semiconductor substrate.

14. The phased array of claim 13, wherein the substrate comprise silicon.

15. The phased array of claim 13, wherein transistors in the circuit comprise bipolar, FET, or hetero-junction bipolar transistors (HBT).

16. The phased array of claim 15, comprising CMOS, BJT, or silicon-germanium transistors.

17. The phased array of claim 12, wherein plurality of tuned amplifiers comprises a plurality of amplifier differential pairs.

18. The phased array of claim 13, wherein the phase-locked loop is disposed on the substrate.

19. The phased array of claim 18, wherein the plurality of antennas are disposed on the substrate.

20. The phased array of claim 12, further comprising a second phase shifter inserted in second ring coupled to the plurality of tuned amplifiers, wherein the second phase delay structure provides a second phase delay between each pair of successive tuned amplifiers.

21. A method of using a variable phase ring oscillator comprising:

applying a signal to a variable phase ring oscillator coupled to a plurality of antennas;

providing a phase shift to the signal within the ring oscillator;

locking the phase and/or frequency of the ring oscillator with a phase locked loop; and

associating a phase shift and amplitude of a signal with a direction for the plurality of antennas.

22. The method of claim 21, wherein applying a signal to a variable phase ring oscillator comprises transmitting a signal from variable phase ring oscillator coupled to the plurality of antennas.

23. The method of claim 21, wherein applying a signal to a variable phase ring oscillator comprises receiving a signal from variable phase ring oscillator coupled to the plurality of antennas.

24. The method of claim 22, further comprising modulating a carrier signal.

25. The method of claim 24, wherein modulating a carrier signal comprises a phase or frequency modulation scheme.

26. The method of claim 24, wherein the modulation scheme comprises FM, PM, PSK, FSK modulation.

27. The method of claim 23, further comprising demodulating a carrier signal.

28. The method of claim 27, wherein demodulating a carrier signal comprises a phase, frequency, or demodulation scheme.

29. The method of claim 24, wherein the demodulation scheme is selected from the group consisting of QAM, OFDM, BPSK, AM, FM, PM, QPSK, FSK, and PSK.

30. The method of claim 21, further comprising determining a distance to a target object using the signal applied to the variable phase ring oscillator coupled to a plurality of antennas.

31. The method of claim 21, wherein the signal applied is a GHz signal.

32. The method of claim 31, wherein the signal applied is in a 2.4 GHz, 5 GHz, 22-29 GHz, 59-64 GHz, 71-76 GHz, 77-78 GHz, 81-86 GHz, or 92-95 GHz band.

33. The method of claim 30, wherein determining a distance comprises determining a distance from an object to an automobile connected to the variable phase ring oscillator coupled to the plurality of antennas.

34. The method claim 33, further comprising determining relative direction from the automobile to the object.