A Capacitive Fed Microstrip Patch Antenna with Air Gap for Wideband Applications (RESEARCH NOTE)

In this paper a microstrip antenna on a suspended substrate with capacitive feed is presented. capacitive feed is created by a slot within the rectangular patch around the feed point. The proposed antenna exhibits a much higher impedance bandwidth of about 47% (S11 < −10 dB). Effects of key design parameters such as the air gap between the substrate and the ground plane, the gap width between radiator patch and feed point, and the location of the feed point on the input characteristics of the antenna have been investigated and discussed. A prototype of the antenna is also fabricated and tested, to verify the design. Measured characteristics of the antenna are in good agreement with the simulated results.