PHASED ARRAY TRANSMISSION METHODS AND APPARATUS

• US 20130120190A1
• Filed: 11/14/2011
• Published: 05/16/2013
• Est. Priority Date: 11/14/2011
• Status: Active Grant

• Current Assignee: Earl W. Mccune Jr
• Original Assignee: Earl W. Mccune Jr
• Inventors: McCune, Earl W. Jr.
• Granted Patent: US 9,041,602 B2
• Time in Patent Office: Days
• US Class Current: 342/368
• 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 3/28 varying the amplitude
• CPC Class Codes: H01Q 3/30 varying the relative phase between the radiating elements of an array H01Q3/2605, H01Q3/2658, H01Q3/2682, H01Q3/44 take precedence
• CPC Class Codes: H01Q 3/34 by electrical means active lenses or reflecting arrays H01Q3/46
• CPC Class Codes: H01Q 3/42 using frequency-mixing H01Q3/2676 takes precedence
• CPC Class Codes: H03B 5/1852 the semiconductor device being a field-effect device

Abstract

A phased array transmitter includes a plurality of vector modulators, an in-phase/quadrature (I/Q) signal generator, and a multiphase generator. The output phases of the plurality of vector modulators, and hence the direction of transmission of the phased array transmitter, are set and controlled by adjusting both the magnitude ratios of I/Q signal pairs generated by the I/Q signal generator and applied to I and Q inputs of the plurality of vector modulators and phases of a plurality of local oscillator (LO) signal phases generated by the multiphase generator and applied to LO inputs of the plurality of vector modulators. Setting and controlling the output phases of the vector modulators by varying both the magnitude ratios of the I/Q signal pairs and the phases of the LO signal phases allows the output phases of the plurality of vector modulators to be more precisely set and controlled than if the output phases were to be set and controlled only through the LO paths or only through the I/Q signal paths of the plurality of vector modulators.

Claims

1. A phased array transmitter, comprising:

a plurality of vector modulators, each vector modulator having in-phase and quadrature (I/Q) inputs and a local oscillator (LO) input;

an I/Q signal generator configured to generate I/Q signal pairs for the I/Q inputs of said plurality of vector modulators; and

a multiphase generator configured to generate a plurality of LO signal phases for the LO inputs of said plurality of vector modulators,

wherein both the magnitude ratios of the I/Q signal pairs applied to the I/Q inputs of said plurality of vector modulators and the LO signal phases applied to the LO inputs of said plurality of vector modulators are varied to set and control a desired direction of transmission.

2. The phased array transmitter of claim 1, wherein the LO signal phases are used to coarsely set the output phases of said plurality of vector modulators and the I/Q signal pairs are used to finely rotate the coarsely set output phases to final precision output phases.

3. The phased array transmitter of claim 1, wherein the I/Q signal pairs are used to coarsely set the output phases of said plurality of vector modulators and the LO signal phases are used to finely rotate the coarsely set output phases to final precision output phases.

4. The phased array transmitter of claim 1, wherein said I/Q signal generator comprises a digital signal processor (DSP) configured to control the magnitude ratios of the I/Q signal pairs.

5. The phased array transmitter of claim 4, wherein said DSP is further configured to control the LO signal phases applied to the LO inputs of said plurality of vector modulators.

6. The phased array transmitter of claim 4, further comprising a plurality of digital-to-analog converters (DACs) configured to convert digital I/Q signal pairs from said DSP to analog I/Q signal pairs, said DACs having a bit resolution high enough to allow said analog I/Q signal pairs to be used to correct for phase inaccuracies in the output phases of said plurality of vector modulators.

7. A method of setting and controlling the output phases of a phased array transmitter, comprising:

generating a plurality of in-phase/quadrature (I/Q) signal pairs;

generating a plurality of local oscillator (LO) signal phases;

coarsely setting output phases of a plurality of vector modulators using said plurality of LO signal phases; and

finely rotating the coarsely set output phases to final desired output phases using said plurality of I/Q signal pairs.

8. The method of claim 7, wherein generating said plurality of in-phase/quadrature (I/Q) signal pairs includes weighting the plurality of in-phase/quadrature (I/Q) signal pairs in response to I/Q phase control data.

9. The method of claim 8, wherein said I/Q phase control data is based on a predetermined transmission algorithm.

10. The method of claim 8, wherein said I/Q phase control data is based on a measure of received signal strength or received signal quality of a receiving target.

11. The method of claim 7, wherein coarsely setting the output phases of the plurality of vector modulators using said plurality of LO signal phases is performed in accordance with a predetermined transmit algorithm.

12. The method of claim 7, wherein coarsely setting the output phases of the plurality of vector modulators using said plurality of LO signal phases is performed based on the strength or quality of a signal received at a receiving target.

13. The method of claim 7, wherein finely rotating the coarsely set output phases to final desired output phases is performed based on the strength or quality of a signal received at a receiving target.

14. A method of setting and controlling the output phases of a phased array transmitter, comprising:

generating a plurality of in-phase/quadrature (I/Q) signal pairs;

generating a plurality of local oscillator (LO) signal phases;

coarsely setting output phases of a plurality of vector modulators using said plurality of I/Q signal pairs; and

finely rotating the coarsely set output phases to final desired output phases using said plurality of LO signal phases.

15. The method of claim 14, wherein generating said plurality of LO signal phases includes shifting said plurality of LO signal phases in accordance with a predetermined transmit algorithm.

16. The method of claim 14, wherein generating said plurality of LO signal phases includes shifting said plurality of LO signal phases based on the strength or quality of a signal received at a receiving target.

17. The method of claim 14, wherein finely rotating the coarsely set output phases to final desired output phases is performed based on the strength or quality of a signal received at a receiving target.

18. A method of adjusting the phase of an electrical signal, comprising:

coarsely rotating an output phase of a vector modulator by varying the magnitudes of in-phase (I) and quadrature (O) signals applied to I and Q inputs of the vector modulator; and

finely rotating the coarsely set output phase of the vector modulator to a desired output phase by finely shifting the phase of a local oscillator of said vector modulator.

19. A method of adjusting the phase of an electrical signal, comprising:

coarsely rotating an output phase of a vector modulator by coarsely shifting the phase of a local oscillator of a vector modulator; and

finely rotating the coarsely set output phase of the vector modulator to a desired output phase by finely varying the magnitudes of in-phase (I) and quadrature (Q) signals applied to I and Q inputs of the vector modulator.