Impact of CSRR Incorporation in Lowering Resonant Frequency of X-Band SIW Antenna

In this paper, the impact of complimentary split ring resonator (CSRR) incorporation in lowering resonant frequency of X-band substrate integrated waveguide (SIW) antenna is investigated. Two concentric ring slots of CSRR are incorporated into the radiator of X-band SIW antenna which is constructed by an extended half-circle shape and fed using a microstrip line. A 1.6mm thick FR4 epoxy dielectric substrate with the dimension of 36mm by 22mm is used to deploy the proposed antenna. In order to shows the potency of resonant frequency lowering by incorporating CSRR structure, the conventional antenna, i.e. an X-band SIW antenna without CSRR, is also designed using the same dielectric substrate. The characterization result shows that the proposed X-band SIW antenna could resonate at the frequency of 12% lower than the conventional antenna without any significant changes in other radiation characteristics.