KA band-pass filter based on the microstrip-groove gap waveguide technology

This paper presents the design of a Ka band narrow bandpass filter, it was realized with a new microstrip-groove gap waveguide transmission structure. The newly microstrip-groove gap waveguide employs period located via holes in the substrate to replace the bed of nails in the conventional groove gap waveguide, and the groove can be obtained by cutting the relative area like groove in the dielectric substrate. According to the above procedure, this kind of new transmission structure can reduce both the fabrication difficulty and cost largely, especially up to Millimetre wave (MMW) frequency. After mass simulation and optimization analysis, the simulated filter has 1.03% bandwidth, and the out of band suppression level can reach 89dB.