Design Of X Band Doppler Radar Front-End

An X band low cost, simple and compact continuous wave Doppler radar is presented. The whole front end is designed using hybrid microwave integrated circuits (MIC). The key components of the radar such as mixer, oscillator and antenna are designed using EDA software and tested individually. For mixer, a single balanced configuration is chosen, the tested conversion loss is 7dB; for oscillator, a high-Q reflection type dielectric resonator oscillator (DRO) is chosen, the tested phase noise is -116dBc/Hz@100kHz with output power of 10.4dBm; for antenna, a 2×2 microstrip antenna array configuration is chosen, the simulated gain is 11dB. Then the whole radar front-end is integrated and tested, the result shows that the radar can be used to detect low speed moving target.Two different kinds of radar are also introduced briefly. One is continuous wave radar, using additional phase modulation on transmitted signal to reduce the effect of 1/f noise. The other is pulse radar, using the same Schottky diodes as pulse modulator of transmitter and mixer of receiver to lower the cost.