Method of multi-channel calibration for digital array radar

Amplitude and phase errors among multi-channels in digital array radar will seriously deteriorate the performance of digital beam-forming (DBF) and high resolution direction finding. This paper describes a practical calibration algorithm that calibrates amplitude and phase errors coarsely using interior calibration source and then realizes precise calibration by eigen-decomposition approach. Based on an 8-elements digital array radar test-bed operating at L & S band, experiments are carried out in the anechoic chamber and outdoors. After calibration, the radiation pattern is nearly ideal and the direction of arrival (DOA) estimation of measured data achieves a good performance. The expected results illustrate that interior-auto calibration algorithm is fairly effective and feasible in actual systems.