System and method for cancelling phase noise induced by antenna vibration

• US 9,973,286 B2
• Filed: 09/22/2016
• Issued: 05/15/2018
• Est. Priority Date: 09/22/2016
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Ward, John Strawn
• Primary Examiner(s): VARNDELL, ROSS E
• Application Number:
  US15/273,207
• Publication Number:
  US 20180083718A1
• Time in Patent Office: 600 Days
• CPC Class Codes: H01Q 1/005 Damping of vibrations; Means for reducing wind-induced forces
• CPC Class Codes: H01Q 1/1242 Rigid masts specially adapted for supporting an aerial
• 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: H04B 1/40 Circuits
• CPC Class Codes: H04B 15/04 the interference being caused by substantially sinusoidal oscillations, e.g. in a receiver or in a tape-recorder
• CPC Class Codes: H04B 17/21 for calibration; for correcting measurements
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]

Abstract

System and method for correcting a phase noise generated by vibration of an antenna transmitting or receiving a radio frequency (RF) signal in a signal propagation direction includes: measuring the vibration of the antenna by a sensor generating an output signal; converting the output signal of the sensor to a measurement signal proportional to the vibration of the antenna in the signal propagation direction; performing a single or double integral of the measurement signal to produce a control signal with an amplitude proportional to the vibrational velocity or displacement of the antenna in the signal propagation direction; and applying the control signal to an oscillator, a clock signal, or a phase controller associated with the RF signal.

Claims

1. A system for correcting a phase noise generated by vibration of an antenna transmitting or receiving a radio frequency (RF) signal in a signal propagation direction comprising:

one or more sensors for measuring the vibration of the antenna and generating an output signal;

a projector for converting the output signal of the sensors to a measurement signal proportional to acceleration of the vibration of the antenna in the signal propagation direction; and

an integrator for performing a single integral of the measurement signal to produce a control signal with an amplitude proportional vibrational Doppler velocity of the antenna in the signal propagation direction, wherein the control signal is applied, as a frequency compensation, to an oscillator or a clock signal associated with the RF signal.

2. The system of claim 1, further comprising a filter for filtering out high vibrational frequency noise and/or low vibrational frequency drift from the measured vibration.

3. The system of claim 1, wherein the RF signal is a transmit signal, and wherein the output of the oscillator or a clock signal is used by a transmitter to set the output frequency of the transmitter, and a frequency of the oscillator or clock signal is controlled by the control signal.

4. The system of claim 1, wherein the RF signal is a receive signal, and wherein the output of an oscillator or a clock signal is used by a receiver to set a tune frequency of the receiver, and the frequency of the oscillator or clock signal is controlled by the control signal.

5. The system of claim 1, further comprising a scaler for adjusting the amplitude of the control signal to match a sensitivity of the sensors to a sensitivity of the oscillator or the clock for optimum phase noise cancellation.

6. The system of claim 1, further comprising a summer for combining a set point control signal and an output of a scaler to produce an oscillator or clock set point including the phase noise correction.

7. The system of claim 1, wherein the sensors generate digital signals as output, and wherein the projector and the integrator are digital circuits.

8. The system of claim 1, wherein the sensors generate analog signals as output, and wherein the projector and the integrator are analog or digital circuits.

9. A system for correcting phase noise generated by vibration of an antenna for transmission of a radio frequency (RF) signal in a signal propagation direction comprising:

one or more sensors for measuring the vibration of the antenna and generating an output signal;

a projector for converting the output signal of the sensors to a measurement signal proportional to acceleration of the vibration of the antenna in the signal propagation direction;

an integrator for performing a double integral of the measurement signal to produce a control signal with an amplitude proportional to a vibration displacement of the antenna in the signal propagation direction;

a circuit for applying the control signal to a phase controller associated with the RF signal to modify a phase of the RF signal to generate a modified RF signal for transmission; and

a transmitter for transmitting the modified RF signal by the antenna.

10. The system of claim 9, further comprising a filter for filtering out high vibrational frequency noise and/or low vibrational frequency drift from the measured vibration.

11. The system of claim 9, wherein the RF signal is a transmit signal, and wherein the phase noise is cancelled by adjusting a phase of the transmitted signal to cancel out a corresponding phase of the vibrational displacement of the antenna in the direction of signal propagation.

12. The system of claim 9, wherein the RF signal is a receive signal, and wherein the phase noise is cancelled by adjusting a phase of the received signal to cancel out a corresponding phase of the vibrational displacement of the antenna in the direction of signal propagation.

13. The system of claim 9, further comprising a scaler for adjusting the amplitude of the control signal to match a sensitivity of the sensors to a sensitivity of the phase controller for optimum phase noise cancellation.

14. The system of claim 9, further comprising a summer for combining a set point control signal and an output of a scaler to produce a set point for a phase controller including the phase noise correction.

15. The system of claim 9, wherein the sensors generate digital signals as output, and wherein the projector and the integrator are digital circuits.

16. The system of claim 9, wherein the sensors generate analog signals as output, and wherein the projector and the integrator are analog or digital circuits.

17. A method for correcting a phase noise generated by vibration of an antenna transmitting or receiving a radio frequency (RF) signal in a signal propagation direction, the method comprising:

measuring the vibration of the antenna by a sensor generating an output signal;

converting the output signal of the sensor to a measurement signal proportional to acceleration of the vibration of the antenna in the signal propagation direction;

performing a single integral of the measurement signal to produce a control signal with an amplitude proportional to vibrational Doppler velocity of the antenna in the signal propagation direction; and

applying the control signal, as a frequency compensation, to an oscillator or a clock signal associated with the RF signal.

18. The method of claim 17, wherein said converting, performing an integral, and applying are performed in an analog domain or in a digital.

19. A method for correcting a phase noise generated by vibration of an antenna for transmission of a radio frequency (RF) signal in a signal propagation direction, the method comprising:

measuring the vibration of the antenna by a sensor generating an output signal;

converting the output signal of the sensor to a measurement signal proportional to acceleration the vibration of the antenna in the signal propagation direction;

performing a double integral of the measurement signal to produce a control signal with an amplitude proportional to a vibrational displacement of the antenna in the signal propagation direction; and

applying the control signal to a phase controller associated with the RF signal to modify a phase of the RF signal to generate a modified RF signal for transmission; and

transmitting the modified RF signal by the antenna.

20. The method of claim 19, wherein said converting, performing a double integral, and applying are performed in an analog or digital domain.