Substrate Integrated Waveguide Step type Cavity Backed Slot Antenna for Dual-Frequency Applications

In this Paper, we describe a novel design technique to implement dual band substrate integrated waveguide (SIW) cavity backed planar slot antenna. The proposed Antenna exhibits linearly polarized unidirectional radiation, along with high gain and high front to back ratio (FTBR) at both resonant frequency. The unique step type cavity provides better matching, while the rectangular ring slot along with conventional rectangular slot inside the cavity are radiated on its corresponding resonant frequency that will give dual band frequency response for this antenna. First frequency (5.92 GHz) has come due to rectangular ring slot and second band comes (10.85 GHz) due to a conventional rectangular slot inside the ring slot. It has shown that broadband impedance bandwidth of 11.98 % at 10.85 GHz having average gain of 5.76 dBi with FTBR ratio of 23.5 dB and −15 dB maximum cross polarization while at 5.90 GHz it will show 3.38% bandwidth having 2.25 dBi, average gain with 15.43 dB FTBR ratio and −22.35 dB maximum cross polarization obtained.