Dual-Band Hexagonal Cavity Back Slot Antenna Using TM110 and TM210 Modes

In this paper, the hexagonal cavitybacked slot antenna using Substrate Integrated Waveguide (SIW) is proposed for dual-band operation. SIW is a planar form of conventional waveguides which can be easily fabricated on printed circuit boards and integrated with microwave circuits. Several metallic vias are inserted into the substrate to make a Hexagonal Cavity Resonator (HCR). The HCR is loaded with Complementary Split Ring Resonator (CSRR) which decreases the resonant frequency of the modes. The resulted antenna operates in two bands and its impedance bandwidth is 4% and 2.2% at the center frequencies of 4.5 GHz and 5.6 GHz, respectively. The gain at the bore sight direction is 7.2 dB and 4.4 dB at 4.5 GHz and 5.6 GHz, respectively.