For the bad application of a UAV, the threat of invasion, attack, and reconnaissance from enemies is getting emphasized nowdays. A drone easily used in the real life is small and it has a very low RCS value. For the purpose to detct a drone, a Ku band FMCW radar was designed and implemented. The specification of the proposed radar system was calculated and the performance of the proposed radar system was measured. For the radar system with high sensitivity, the method was analyzed. High isolation between the Tx part and the Rx part was realized with the separation of each antenna maintaining the whole system synchronization. Delay line measurement and rooftop drone measurement were carried out to check the operation of the proposed radar system. Target speed and target distance are obtained using a FMCW radar signal processing technique.