Method and system for antenna array calibration for cross-coupling and gain/phase variations in radar systems

A radar system comprising:

• a plurality of transmitters, each communicatively coupled to a transmitter antenna array, wherein each transmitter of the plurality of transmitters is configured to transmit radio signals via the transmitter antenna array;
• a plurality of receivers, each communicatively coupled to a receiver antenna array, wherein each receiver of the plurality of receivers is configured to receive radio signals via the receiver antenna array that include radio signals transmitted by the transmitters and reflected from objects in an environment;
• a calibration module comprising a platform configured to rotate the transmitter antenna array and the receiver antenna array in azimuth and/or elevation, wherein respective array centers of the transmitter antenna array and the receiver antenna array are not aligned with the platform's rotation center;
• wherein the calibration module is configured to access receiver data from each receiver of the plurality of receivers for each of a plurality of azimuth and/or elevation angles as the platform is rotated, wherein the calibration module is operable to calculate a respective misalignment value for each receiver of the plurality of receivers from the receiver data to define a misalignment between the array center of the receiver antenna array and the rotation center of the platform.

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 transmitter and the receiver are coupled to an antenna array;
• rotating, with a platform, the antenna array 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 data defined by received radio signals reflected from the at least one object at selected azimuth and/or elevation angles, and 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, antenna calibration errors that accounts for 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.