True time delay diversity beamforming

• US 8,259,005 B1
• Filed: 03/12/2010
• Issued: 09/04/2012
• Est. Priority Date: 03/18/2009
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Lam, Lawrence K., Ngo, Albert
• Primary Examiner(s): Sotomayor, John B
• Application Number:
  US12/722,670
• Time in Patent Office: 907 Days
• Field of Search: 342/174, 342/81, 342 83- 88, 342157-158, 342/368, 342371-375
• US Class Current: 342/174
• CPC Class Codes: H01P 1/184 Strip line phase-shifters H01P1/181, H01P1/185, H01P1/19 take precedence
• 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: H01Q 3/2694 using also variable phase-shifters H01Q3/2688 takes precedence

Abstract

A true time delay beamforming system and calibration method for transmission and reception of a beam is disclosed. The true time delay beamforming system comprises at least one input signal received by at least one signal conditioning device, wherein the signal conditioning device is adapted to provide selective, independent, and variable control of one of a phase delay, a time delay and an amplitude of the input signal to produce an output signal. A control logic device is adapted to provide a control logic signal to the at least one signal conditioning device for selectively activating and controlling the signal conditioning device. The true time delay beamforming system may further include an automatic calibration system that generates an error correction signal based on errors detected in the output signal, and selectively adjusts the control logic signal based thereon.

Claims

1. A true time delay beamforming system, comprising:

at least one signal conditioning device receiving at least one input signal, wherein the signal conditioning device is adapted to provide selective, independent, and variable control of one of a phase, a time delay and an amplitude of the input signal to produce an output signal;

a control system adapted to provide a control logic signal to the at least one signal conditioning device for selectively activating and controlling the signal conditioning device; and

a calibration system for detecting and correcting error in at least one of a phase, a time delay and an amplitude of the output signal, wherein the calibration system comprises a channel signal and noise characterization unit adapted to receive the output signal and to detect phase, amplitude, and time errors to generate an estimated error correction signal therefrom, the error correction signal received by the control system for selectively generating the control logic signal.

2. The true time delay beamforming system of claim 1, wherein the control system further receives an external input, the external input being utilized in combination with the estimated error correction signal by the control system to generate the control logic signal.

3. The true time delay beamforming system of claim 1, wherein a sampling system adapted to sample the output signal provides the output signal to the channel signal and noise characterization unit.

4. The true time delay beamforming system of claim 1, wherein the signal conditioning device produces a plurality of output signals, at least one of which is received by the channel signal and noise characterization unit.

5. The true time delay beamforming system of claim 4, further comprising an antenna in signal communication with the at least one signal conditioning device, the at least one input signal received from the antenna.

6. The true time delay beamforming system of claim 4, further comprising an antenna in signal communication with the at least one signal conditioning device to receive and radiate the output signal.

7. The true time delay beamforming system of claim 1, wherein the at least one input signal is received by the signal conditioning device as a portion of the control logic signal.

8. A true time delay beamforming network, comprising:

a plurality of signal conditioning devices, wherein each of the signal conditioning devices receives an input signal and conditions the input signal by independently and selectively adjusting at least one of a time delay, a phase, and an amplitude of the input signal to produce an output signal;

a control system adapted to provide a control logic signal to the at least one signal conditioning device for selectively activating and controlling the signal conditioning device; and

a channel signal and noise characterization unit adapted to detect phase, amplitude, and time errors in the output signal to generate an estimated error correction signal therefrom, the error correction signal received by the control system for selectively generating the control logic signal.

9. The true time delay beamforming system of claim 8, wherein a sampling system adapted to sample the output signal provides a signal representative of the output signal to the channel signal and noise characterization unit, the sampled signal utilized to generate the error correction signal.

10. The true time delay beamforming system of claim 8, wherein each of the plurality of signal conditioning device devices produces a plurality of output signals, at least one of which is received by the channel signal and noise characterization unit and is utilized to generate the error correction signal.

11. The true time delay beamforming system of claim 8, further comprising at least one antenna in signal communication with the plurality of signal conditioning devices, each input signal received from the at least one antenna.

12. The true time delay beamforming system of claim 8, further comprising an antenna in signal communication with the at least one of the plurality of signal conditioning devices to receive and radiate the output signal.

13. The true time delay beamforming system of claim 8, wherein the input signal is received by the plurality of signal conditioning devices as a portion of the control logic signal.

14. A method for calibrating a true time delay beamforming system, comprising:

receiving a reference signal;

adjusting at least one of a time delay, a phase, and an amplitude of the reference signal in a signal conditioning device to create an output signal;

receiving a calibration signal representative of the output signal in a channel signal and noise characterization unit;

comparing the calibration signal for errors in at least one of a time delay, a phase and an amplitude to predetermined values to generate an error correction signal therefrom; and

selectively generating a control logic signal based on the error correction signal, the control logic signal transmitted to the signal conditioning device to modify the adjusting step.

15. The method for calibrating a true time delay beamforming system of claim 14, wherein the reference signal is received from a control system.

16. The method for calibrating a true time delay beamforming system of claim 15, wherein the comparing step includes comparing the time delay, the phase, and the amplitude to known values.

17. The method for calibrating a true time delay beamforming system of claim 15, wherein the comparing step includes comparing the time delay, the phase, and the amplitude to values in a look-up table.