Design of a Ka-band High Power Oversized Waveguide Mode Filter

In this paper, a Ka-band oversized waveguide mode filter for circular TE01mode high power transmission line is proposed. By optimizing the three dimensional periodic structure, the parasitic modes such as TE11, $TE_{21}, TM_{11}$ and $\pmb{TE}_{31}$ can be effectively filtered with an insertion loss more than 10 dB while the TE01suffers little attenuation with the insertion loss less than 0.1 dB after propagating through the proposed device in the range of 26 GHz to 31 GHz. The proposed waveguide filter features high in power capacity, low in insertion loss, and simple in structure.