EXPERIMENTAL AND SIMULATION STUDIES OF THE COAXIALLY FED U-SLOT RECTANGULAR PATCH ANTENNA

Experimental and simulation results are presented on the coaxially fed rectangular patch antenna with a U-shaped slot. Experimental results include impedance bandwidth, copolar- and crosspolar-pattern character istics and gain measurements. Simulation results are obtained mainly t hrough the development of a FDTD code. It is found that the U-slot pat ch on a foam substrate of about 0.08 lambda thick can be designed to a ttain 20-30% impedance as well as gain bandwidths without the need of parasitic patches on another layer or on the same layer. The far-field patterns have good copolar and crosspolar characteristics. By alterin g the patch width or feed position, the wideband characteristic can be changed into a dual-frequency characteristic. Simulation results are in good agreement with measurements.