Abstract: This paper designs a high cost-effectiveness ratio broadband millimeter-wave phased array radar, which includes high cost-effectiveness ratio and low lobe antenna array structure, wide and narrow band integrated transceiver link and low cost open reconfigurable backend devices, it has the characteristics of high cost-effectiveness ratio, broadband wide-angle scanning, broadband DBF conversion and backend commercialization, etc. By using the broadband amplitude-phase distortion compensation method, The HRRP main to side lobe ratio of the space target has increased from 0.2dB to 28dB. It is the first time in China to realize stable tracking and high-resolution ISAR imaging of typical LEO space targets by Ka band millimeter wave phased array radar.