Dual band square microstrip antenna embedded with a shaped slot

Dual frequency operation of a single feed slotted square microstrip antenna is demonstrated. The two operating frequencies have the same polarisation planes, and by changing the slot parameters various frequency ratios of the two frequencies can be achieved. It is observed that, for fixed dual frequency operation, the proposed antenna provides a size reduction up to /spl sim/50% and 43% for the two modes as compared to a regular microstrip antenna.