A W-band Silicon-based Waveguide Over-mode Cavity Slot Array Integrated with Dumbbell-Shaped Holey-EBG Structures

The W-band over-mode cavity slot array with novel dumbbell-shaped (DS) holey electromagnetic band gap (EBG) structures is presented. The proposed DS holey EBG structures can effectively suppress the electromagnetic (EM) leakage between multilayer metallic silicon-based (Si-based) plates. Its mechanism is explored and investigated in detail. By exciting high-order modes, a wideband 8×8 antenna array with and without DS holey EBG structures is designed and fabricated. The measured gains of the test antenna with holey EBG units are improved by 1-2 dB compared to the antenna without holey-EBG units, indicating that the proposed DS holey-EBG structure effectively suppresses the EM leakage within multilayer metallic waveguides. The measured -10-dB impedance-matching bandwidth ranges from 90 to 109.5 GHz (19.5% of fractional bandwidth), and its maximum gain reaches as high as 25.1 dBi at 94.5 GHz.