Numerical simulation of novel TM01-TE11 mode converter with slow-wave structures

A novel mode converter with slow-wave structures is investigated. The circular waveguide is separated into two regions by a metal plate. One is a regular 180° sector waveguide, the other is inserted with slow-wave structures. The input circular TM01 mode excites two sector TE11 modes which propagate at different phase velocities in the two regions. Adjusting the parameters of the SWSs, the two sector TE11 modes have various phase difference. At the end of the plate the two sector TE11 modes with 180° phase difference couple into the circular TE11 mode to finish the TM01-TE11 mode conversion. The input and output is aligned on the same axis, which is helpful for the compactness of the microwave lunching systems. Numerical simulations reveal that at the operating frequency of 1.8 GHz the c