Wideband Differentially-Fed Substrate Integrated Waveguide (SIW) Back Cavity Antenna

A wideband differentially-fed substrate integrated waveguide (SIW) back cavity antenna is proposed for operation at 34 GHz millimeter bands. A wide rectangular slot is etched on the top of SIW back cavity loading with three square patches. The rectangular cavity with four tuning vias is employed for two resonant cavity modes and wideband operation. The transition between standard rectangular waveguide (RWG) and SIW are inspired by the same technology. The simulation shows that the impedance matching of the antenna without and with the transition for return loss better than 10 dB is 26–46 GHz (55.6%) and 26.2–42 GHz (46.3%) with the achieved gain of 6.7–9.2 dBi and 6–7.5 dBi, respectively. The proposed antenna features the advantages of low-profile and wideband, suitable for the full Ka-band system applications.