A novel band-pass filter topology for millimeter-wave applications based on the groove gap waveguide

In this paper a new type of band-pass filters for high frequency applications (40 GHz and beyond), with very good electrical performance and enhanced manufacturing flexibility, is demonstrated. These filter structures are based on the recently proposed groove gap waveguide, which is just made of two simple metal blocks separated by an air gap. This means that electrical contact between the two metal blocks is not needed, thus involving several advantages when compared to standard rectangular waveguide filters operating at millimeter-waves. A 4^th order band-pass filter with a response centered at 40 GHz and a 2.5% fractional bandwidth has been designed, manufactured and verified with experimental results.