Antenna radiation pattern effects on a short-range vibration-detection radar system

This paper presents a 5.8 GHz Doppler noncontact vibration-detection radar system with 2×2 patch array antennas and single patch antennas. Two different types of antennas are used on both transmitter (Tx) and receiver (Rx) sides, alternately. An actuator is connected with a 16 cm × 14 cm metal plate and generates a 1 Hz sinusoidal movement with 1 mm peak-to-peak displacement. The system can successfully detect a target´s vibration when it is vertically misaligned with the target by 31° and placed at 0.5 m away. The system with the broad beamwidth antennas shows the best result.