Analysis of slot loaded microstrip patch antenna

The analysis of a slot loaded rectangular microstrip patch antenna using equivalent circuit concept is presented. The slot is taken as a capacitive reactance on the patch. It is found that the resonance frequency decreases with increasing slot width for a given slot length. Further it is observed that VSWR remains almost invariant with slot width and slot length and the impedance increases almost linearly with the slot width but inversely with the slot length. This antenna shows dual frequency behavior corresponding to TM/sub 100/ and TM/sub 300/ modes.