The Versatile U-Slot Patch Antenna

The U-slot patch antenna was originally developed as a single-layer, single-patch wideband antenna. It has recently been shown that it can also be designed to perform a number of other functions. In this paper, a comprehensive account is given on the development of this antenna. Emphasis is placed on experimental and simulation results for various U-slot topologies, illustrating the antenna's versatility in several practical applications. These include wideband, dual- and triple-band operation with small and large frequency ratios, as well as for circular-polarization applications.