Capacitive-coupled groove gap waveguide filter

Paper in proceeding, 2018

— Recently introduced gap waveguide is a good candidate as a guiding technology especially for frequency over 40GHz. Among different type of gap waveguides, groove gap waveguide works like the conventional rectangular waveguide but with no need of electrical contact between two consisting metal blocks of the waveguide. In this paper, a capacitive-coupled groove gap waveguide is presented at the center frequency of 65 GHz. To reduce the cost and fabrication difficulty of manufacturing, the groove gap waveguide is realized on the bottom layer as a guiding structure and some metallic walls are created on the top layer to realize the capacitive irises. Also, the sensitivity of the filter frequency response to the capacitive gap is reduced by an improved capacitive-gap as coupling structure. The required transition of the groove gap waveguide to WR15 is designed. The simulated FBW of the filter is %1.2 with return loss better than 20dB at the center frequency of 65GHz with minimum insertion loss of 0.5dB.