Abstract: The amplitude-phase error model of transmit array in microwave sparse-array synthesis impulse and aperture radar,is constructed in this paper.And two calibration methods,which are near field method based on narrow impulses and far field method based on direct-path waves,are studied.The former method receives different-frequence narrow impulses from the near field antennas,and extracts the amplitude-phase error by channel separating and spectrum analysis.The latter one receives the direct-path waves from the...