Design of a High Gain Low Profile Antenna for a Passive Radar

Abstract

Design of a new high gain antenna is proposed for a radiometric system for detecting human intrusion. Thermal radiations emitted by the human body in the microwave range are sensed by this system. The proposed quasi-planar antenna is designed with wide bandwidth and high gain characteristics. This antenna has a measured peak gain of 13.2 dBi and around 35° beamwidth in both principal planes. The center frequency of operation was chosen to be 3.7 GHz for easy penetration through obstacles, as well as for avoiding radio-frequency interference. The antenna has an impedance bandwidth greater than 45%. The system performance was evaluated and real-life experiments were carried out. Experimental results demonstrated capability of the system to detect the presence of a person upto a distance of 2 m.