An X-band linear frequency-modulated continuous wave(FM-CW) radar, using a single antenna for both transmitting and receiving eletromagnetic energy, is implemented. Due to the mismatching of antenna impedance, the reflected wave signal may be dominant over the small target echo signal, which could be overcomed by using a sharp filter to eliminate the reflected signal of the low frequency in the demodulation unit. The minimum detectable signal (MDS) of the radar developed here is -95dBm, and it reaches an object in 500 meters range by transmitting 10mW power, if its radar cross section(RCS) is the order of 100㎡.
