Compact Microstrip Antenna for Radar Altimeter Applications

A compact rectangular microstrip antenna of size 18 mm × 12 mm × 1.6 mm from FR4 substrate for radar altimeter applications is suggested in this paper. The suggested antenna consists of a stub loaded microstrip line of width 2 mm × 18 mm on one side and partial ground of 1 mm × 12 mm on the other side of the substrate. The position of the stub of dimensions 1 mm × 12 mm decides the range of frequency operation. Even a dual band of operation can be obtained by changing its position. This antenna has an operating frequency from 3.98 GHz to 4.47 GHz with a resonant frequency of 4.22 GHz. The design parameters and the performance of the suggested antenna are investigated by using HFSS.