A Half-Mode Cavity Backed Hybrid Array Antenna Using Substrate Integrated Waveguide (SIW) Technology

This article proposes a hybrid array antenna where a cavity-backed antenna is used jointly with a patch antenna using half-mode substrate integrated waveguide technology (HMSIW) to reduce antenna size. This hybrid structure consists of a flexible Rogers RO4003C substrate ( $\epsilon_{{r}} =3.55$ ) showing linearly polarized TE101 mode where the cross-polarization level (XPL) is less than −12 dBi. An inset feed has been utilized to excite the main cavity resonator, and later by proximity coupling, the parasitic patch is also excited in TE101 mode. By further dividing the outer patch, four new cases of antenna have emerged, and comprehensive investigations on their parameters based on simulation have been presented. It paints an upgrade of the antenna’s performance. As per simulations, further dividing of the patch helps to bring out positive changes in the antenna’s performance by escalating gain, bandwidth (BW), and efficiencies while also lessening XPL, sidelobe levels (SLLs), and associated loss up to a satisfying level. The proposed antenna is then fabricated and experimentally validated in its theoretical analysis. A couple of experimentally validated parameters make this fabricated sample suitable for wireless application and maintain good agreement with numerical simulation. CST Microwave Studio and HFSS carried out the associated numerical simulation.