Abstract: A technique for designing the transceiver front-part system module for Ka-band full coherent radar is proposed. By good frequency programming, circuits designing and the perfect use of DDS, phase locked loop(PLL) and FPGA devices, the better performances of spectrum purity (phase noise and spur lever) and converting time are obtained, and a high-performance transceiver front-part module is developed. The measurement results show that in S/C band, when the minimum frequency step is 15M Hz and the bandwidth is 480 MHz, the measured transmitter spur is less than ?65 dBc, the corresponding receiver spur is less than ?70 dBc, the measured phase noise is less than ?94 dBC/Hz@1 kHz, and the maximum frequency switching time is less than 15 μs.