6–18GHz single ridge waveguide UWB absorbent harmonic filter

In this paper, a new type of 6–18GHz UWB absorbent harmonic filter is present which constructed by a primary single ridge waveguide and single row accessorial rectangular waveguide loads. Comparing with of the 2–4GHz UWB absorbent harmonic filter presented in above paper, the 6–18GHz filter has lower SWR and insert loss in 6–18GHz ultra-wide pass band, and also has lower SWR and higher isolation in 26.5–40GHz ultra-wide stop band.