Self-organized antenna array calibration

The performance of direction finding algorithms is severely degraded by any phase and amplitude error between the adjacent elements of an array antenna. Due to analog hardware behavior these errors are time-varying and depend on temperature, component aging and other component specific characteristics. Therefore, the calibration coefficients have to be updated periodically and adaptively during radar system operation. This paper presents a digital signal processing scheme which is able to estimate and update phase and amplitude distortions for any individual antenna element inside an uniform linear antenna array. This calibration algorithm works solely with the received signals from each antenna element in the array and does not need any reference signal and no extra analog hardware [1]. The performance results of the investigated calibration procedure are very promising and the radar system overhead is extremely small, making it a very good algorithm for continuous monitoring of the antenna array.