Enhanced gain UWB slot antenna with multilayer Frequency-Selective Surface reflector

Adequately design Frequency Selective Surfaces (FSSs) allow significant control of the phase of reflection and transmission characteristics over a wide frequency band. This property is used here to develop a multilayer FSS reflector enhancing the gain and radiation properties of antennas for ultra wideband applications. These kinds of reflectors make structures low profile by providing the flexibility in mounting them closer to antenna without disturbing the impedance bandwidth and providing a good gain control in the main beam direction. In order to design a suitable reflector dual layer FSS have been designed and employed with a slot antenna. FSS layer works from 4 GHz to 12 GHz, providing a linear transmission phase in the 133% bandwidth. Performance of the FSS is tested with UWB slot antenna and predicted results show significant gain enhancement while maintain the bandwidth of 140%.