Extending beamforming capability of a coupled voltage controlled oscillator (VCO) array during local oscillator (LO) signal generation through accommodating differential coupling between VCOs thereof

• US 9,531,070 B2
• Filed: 03/17/2014
• Issued: 12/27/2016
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Original Assignee: Gigpeak, Inc. (Renesas Electronics Corporation)
• Inventors: Schiller, Christopher T.
• Primary Examiner(s): LIU, HARRY K
• Application Number:
  US14/215,977
• Publication Number:
  US 20140266892A1
• Time in Patent Office: 1,016 Days
• Field of Search: 342367-369, 342/374
• US Class Current: 1/1
• CPC Class Codes: H01Q 3/42 using frequency-mixing H01Q3/2676 takes precedence

Abstract

A method includes implementing a coupled Voltage Controlled Oscillator (VCO) array with a number of VCOs, and mixing Local Oscillator (LO) signals generated through the number of VCOs of the coupled VCO array with signals from antenna elements of an antenna array to introduce differential phase shifts in signal paths coupled to the antenna elements during performing beamforming with the antenna array. The method also includes accommodating differential coupling between the VCOs to improve immunity to noise and/or interference during the beamforming compared to the VCOs accommodating single-ended coupling therebetween.

Claims

1. A method comprising:

implementing a coupled Voltage Controlled Oscillator (VCO) array with a plurality of VCOs;

mixing Local Oscillator (LO) signals generated through the plurality of VCOs of the coupled VCO array with signals from antenna elements of an antenna array to introduce differential phase shifts in signal paths coupled to the antenna elements during performing beamforming with the antenna array;

accommodating differential coupling between the VCOs to achieve an improved immunity to at least one of;

noise and interference during the beamforming, wherein the improved immunity is better than an immunity of the VCOs accommodating single-ended coupling instead of the differential coupling therebetween;

injection locking two or more VCOs of the coupled VCO array to each other; and

coupling a VCO of the coupled VCO array to another VCO thereof through a differential bidirectional coupling circuit.

2. The method of claim 1, further comprising implementing differential phase inversion circuitry at least one of:

between the VCOs and in a path of injection of a reference input signal into the coupled VCO array to increase a range of phase difference provided therethrough, the reference input signal being configured to control operating frequency of the coupled VCO array.

3. The method of claim 2, comprising implementing the differential phase inversion circuitry with a plurality of switches, a phase inversion provided through the differential phase inversion circuitry being accomplished based on a position of switches of the plurality of switches.

4. The method of claim 1, comprising providing one of:

a one-dimensional, a two-dimensional and a three-dimensional VCO array as the coupled VCO array.

5. The method of claim 1, further comprising at least one of:

combining outputs of the mixing at a combiner circuit as part of the beamforming; and

expanding a number of the coupled VCO array based on a requirement of the beamforming.

6. A beamforming system comprising:

a coupled VCO array comprising a plurality of VCOs coupled to one another;

an antenna array comprising a plurality of antenna elements; and

a plurality of mixers, each of which is configured to mix an LO signal generated through a VCO of the coupled VCO array with a signal from an antenna element of the antenna array to introduce differential phase shifts in signal paths coupled to the antenna elements during performing beamforming with the antenna array,

wherein the VCOs are configured to accommodate differential coupling therebetween to achieve an improved immunity to at least one of;

noise and interference during the beamforming, wherein the improved immunity is better than an immunity of the VCOs accommodating single-ended coupling instead of the differential coupling therebetween, and

wherein at least one of;

the beamforming system further comprises a combiner circuit to combine outputs of the plurality of mixers as part of the beamforming, and

a number of the coupled VCO array is configured to be expanded based on a requirement of the beamforming.

7. The beamforming system of claim 6, further comprising differential phase inversion circuitry implemented at least one of:

between the VCOs and in a path of injection of a reference input signal into the coupled VCO array to increase a range of phase difference provided therethrough, the reference input signal being configured to control operating frequency of the coupled VCO array.

8. The beamforming system of claim 7, wherein the differential phase inversion circuitry is implemented with a plurality of switches, a phase inversion provided through the differential phase inversion circuitry being accomplished based on a position of switches of the plurality of switches.

9. The beamforming system of claim 6, wherein two or more VCOs of the coupled VCO array are injected locked to each other.

10. The beamforming system of claim 9, further comprising a differential bidirectional coupling circuit to couple a VCO of the coupled VCO array to another VCO thereof.

11. The beamforming system of claim 6, wherein the coupled VCO array is one of:

a one-dimensional, a two-dimensional and a three-dimensional VCO array.

12. A wireless communication system comprising:

a beamforming system comprising;

a coupled VCO array comprising a plurality of VCOs coupled to one another,

an antenna array comprising a plurality of antenna elements, and

a plurality of mixers, each of which is configured to mix an LO signal generated through a VCO of the coupled VCO array with a signal from an antenna element of the antenna array to introduce differential phase shifts in signal paths coupled to the antenna elements during performing beamforming with the antenna array, the VCOs being configured to accommodate differential coupling therebetween to achieve an improved immunity to at least one of;

noise and interference during the beamforming, wherein the improved immunity is better than an immunity of the VCOs accommodating single-ended coupling instead of the differential coupling therebetween; and

a receiver channel configured to receive a combined output of the plurality of mixers of the beamforming system,

wherein two or more VCOs of the coupled VCO array of the beamforming system are injected locked to each other, and

wherein the beamforming system further comprises a differential bidirectional coupling circuit to couple a VCO of the coupled VCO array to another VCO thereof.

13. The wireless communication system of claim 12, wherein the beamforming system further comprises differential phase inversion circuitry implemented at least one of:

between the VCOs and in a path of injection of a reference input signal into the coupled VCO array to increase a range of phase difference provided therethrough, the reference input signal being configured to control operating frequency of the coupled VCO array.

14. The wireless communication system of claim 13, wherein the differential phase inversion circuitry of the beamforming system is implemented with a plurality of switches, a phase inversion provided through the differential phase inversion circuitry being accomplished based on a position of switches of the plurality of switches.

15. The wireless communication system of claim 12, wherein the coupled VCO array of the beamforming system is one of:

a one-dimensional, a two-dimensional and a three-dimensional VCO array.