Wideband HMSIW‐based slotted antenna for wireless fidelity application

In this study, a wideband half‐mode substrate integrated waveguide (HMSIW)‐based cavity‐backed slot antenna is proposed for Unlicensed National Information Infrastructure (U‐NII, 5.180–5.825 GHz) band. To reduce the size of the antenna, an HMSIW backing cavity is used. An epsilon‐shaped radiating slot is etched on the top plane of the cavity to achieve a wide −10 dB impedance bandwidth of 13.2% (5.092–5.817 GHz). A planar exponential tapered feeding technique is used to excite the slot. A wideband is realised by coupling of hybrid mode, TM 210 mode, and modified TM 020 modes at the resonant frequencies of 5.2, 5.5, and 5.8 GHz, respectively. The size of the proposed design including a feeding network is 56 mm × 32 mm (1.4 λ g1 × 0.8 λ g1 ). The proposed design is fabricated and experimentally tested. The experimental results show gains of 6.6, 6, and 5.5 dBi and efficiencies of 91, 89, and 87% at the frequencies of 5.2, 5.5, and 5.8 GHz, respectively, with front‐to‐back ratio better than 15 dB. Moreover, the proposed antenna shows a unidirectional radiation pattern including the advantages of low‐profile and lightweight with planar integrity which makes the proposed antenna a favourable candidate for wireless fidelity application.