In this project, 24 GHz front-end modules that transmit and receive direct sequence spread spectrum signals generated from a digital signal processor are designed and fabricated for a K-band short range radar. The DDS(Direct Digital Synthesizer) board is made as a reference signal for a 21.7 GHz local frequency synthesizer. The high-frequency DDS signal of a 21.7 MHz reference signal makes low frequency division ratio, thereby achieving the phase noise of -95 dBc/Hz at 100 kHz offset frequency.