Wideband monopulse antenna system for short range CW RADAR application

A wideband antenna system is used to demonstrate a frequency modulated continuous wave (FMCW) radar in mono pulse configuration in order to extract angle of arrival(AOA) along with the range information. A single element cavity backed wideband coplanar microstrip antenna is used as a transmitter with antenna peak gain being 7.6 dBi whereas two such antennas with rat race coupler is used to create sum and difference signals at the receiving end. Two elements give a peak gain of 11 dBi and 3 dB beamwidth of the sum pattern is 40°. Measured peak sum to difference ratio is around 22 dB. In this configuration, measured range accuracy of ±10 cm whereas measured AOA has an accuracy of ±1°.