Balanced Filter With Wideband Common-Mode Suppression in Groove Gap Waveguide Technology

This letter is focused on the design and realization of balanced bandpass filters (BPFs) in gap waveguide technology. The procedure of filter design and resonance-mode selection to achieve the desired differential bandpass behavior with intrinsic deep and wideband common-mode suppression is explained. A third-order differential BPF is designed and fabricated for demonstration. Agreement between the computed and measured results validates the concept and the design procedure.