Higher-order mode substrate integrated waveguide cavity excitation for microstrip patch antenna arrays at 30 GHz

This paper presents a novel approach to the design and fabrication of low-cost and high-gain aperture-coupled microstrip patch antenna (AC-MPA) arrays with improved radiation pattern for millimetre-wave applications such as simultaneous wireless information and power transfer (SWIPT) and Internet-of-Things (IoT) device connectivity. A higher-order mode substrate integrated waveguide (SIW) cavity is used to feed the MPA arrays through aperture coupling. The improved design approach is introduced and discussed in detail. Simulation and experimental results for 2x2 and 4x4 arrays are presented, demonstrating excellent agreement. Key performance metrics are side-lobe levels of less than -24 dB and -29 dB in the E-plane and -22 dB and -26 dB in the H-plane and realized gain of 11 dBi and 15 dBi for the 2x2 and 4x4 arrays respectively, at a design frequency of 30 GHz.