An Improved Design of Center-Fed SIW Slot Dual-Layered Substrate Antenna

In this paper, a center-fed substrate integrated waveguide (SIW) slot dual-layered substrate antenna is proposed. A bandwidth from 4.86 GHz to 6.75 GHz is obtained with three resonant frequencies. In order to improve the matching performance, 12 slots are introduced in the coupling ring. The refection coefficient of the proposed antenna is improved by more than 20 dB compared to that of the basic antenna without no slot in the ring at 5.88 GHz. A dual-layered substrate (F4B265 and Rogers 5880) is used to optimize the bandwidth. Simulation result display that the antenna reaches up to a bandwidth of 33%. The antenna has a 2 mm low profile and a narrow radius of 38.5 mm. The peak gain of 7.9 dB can be obtained at 6.6 GHz.