Design of ultra wideband hexagonal patch slot antenna for high-gain wireless applications

In this paper, a CPW-fed modified rectangular slot antenna with ultra wideband characteristics is proposed. The slot has on one of its sides, a rectangular extension of smaller size which introduces asymmetry in the design. The CPW feed is terminated on a hexagonal-shape patch which protrudes into the slot centre and excites the slot. The antenna exhibits an impedance bandwidth of 134% at the centre frequency of 8.8 GHz. The radiation patterns of the antenna are simulated and measured and found to have omni-directional characteristics in the H-plane. In order to increase the gain of the antenna and make it directional, a multi-layer FSS is designed and fabricated. By implementing the FSS, the gain is enhanced by 3–4 dBi throughout the band. To verify the time domain performance of the antenna with and without the FSS, the group delay and fidelity factors (FF) are calculated. While the variations in the group delay are seen to be minimal, the FF are found to be within acceptable limits thus indicating good time domain characteristics with no significant loss of information in the received pulse.