Method and system for antenna array calibration for cross-coupling and gain/phase variations in radar systems
AssigneeUhnder, Inc.
InventorsMurtaza Ali, Ali Erdem Ertan, Kevin B. Foltinek
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Abstract
A radar system with on-system calibration for cross-coupling and gain/phase variations includes capabilities for radar detection and correction for system impairments to improve detection performance. The radar system is equipped with pluralities of transmit antennas and pluralities of receive antennas. The radar system uses a series of calibration measurements of a known object to estimate the system impairments. A correction is then applied to the beamforming weights to mitigate the effect of these impairments on radar detection. The estimation and correction requires no external measurement equipment and can be computed on the radar system itself.
Claims20
A radar system configured to calibrate for system impairments, wherein the radar system comprises:
- a transmitter configured to transmit radio signals;
- a receiver configured to receive radio signals that include radio signals transmitted by the transmitter and reflected from objects in an environment, wherein the transmitter and the receiver are coupled to an antenna array;
- a calibration module comprising a platform configured to rotate the receiver and the transmitter in both azimuth and elevation, wherein an array center of the antenna array is not aligned with the platform's rotation center;
- wherein, in the presence of at least one object, the calibration module is operable to collect from the receiver reflected signals from the at least one object at desired angles of interest in azimuth and elevation, wherein the calibration module is operable to calculate a misalignment value for a misalignment between the array center of the antenna array and the rotation center of the platform, and wherein the receiver is operable to correct for phase distortion and angle-of-arrival error due to the misalignment based upon the calculated misalignment value.
A method for calibrating a radar system for system impairments, wherein the method comprises:
- transmitting, with a transmitter, radio signals;
- receiving, with a receiver, radio signals that include radio signals transmitted by the transmitter and reflected from objects in an environment;
- wherein the a transmitter and the a receiver are coupled to an antenna array;
- rotating, with a platform, the receiver and the transmitter in both azimuth and elevation, and wherein an array center of the antenna array is not aligned with the platform's rotational center;
- in the presence of at least one object, collecting from the receiver, with a calibration module, reflected signals from the at least one object at desired angles of interest in azimuth and elevation, calculating a misalignment value for a misalignment between the array center of the antenna array and the rotation center of the platform, and
- correcting, with the receiver, for phase distortion and angle-of-arrival error due to the misalignment based upon the misalignment value, wherein the misalignment between the array center of the antenna and the rotation center of the platform is a nodal displacement, and wherein the array center of the antenna array is a nodal point.
Dependencies are inferred from the claim text.