Researching on the Wideband Elliptical-section TE01-TE11 Mode Converter

The TE01-TE11 mode converter can convert the output mode of gyrotrons(their outputs are TE0n one or more circular modes) into TE11, in high power microwave system. And TE11 could be transformed into linearly polarizedGaussian-like HE11 mode which facilitatestransmission and emission. The conventional researching on circular sections TE01-TE11 mode converter has been widely used. However, it has disadvantages in long length and narrow bandwidth. In this paper, a novel type of wideband Ka-band elliptical cross-section serpentine TE01-TE11 waveguide mode converter is proposedbased on theiterativemethod. This novel mode converter achieved a relative bandwidth 21.97% when the convertingefficiency is over 90%, at center frequency 30.5G. The structure length is only 510mm, which has coaxial-parallel input and output ports with smoothaxial curvature distribution. This researching offers good solutions to the disadvantages of the circular section TE01-TE11mode converter mentioned above.