Wide band and high gain electromagnetically coupled circular microstrip antennas

Experimental results on four electromagnetically coupled circular microstrip antenna configurations have been presented. For the first three configurations, the fed patch was a single circular patch and the parasitic elements consisted of one, four and five circular patches respectively. The antenna with five parasitic patches yielded maximum gain. In the fourth configuration, three hybrid coupled circular patches were used in the bottom layer with one circular patch on the top layer. This configuration yielded maximum bandwidth of 22% but slight beam shift from the broadside direction was observed.