Improved Based on 9-fold helical corrugated waveguide high-power TM01-TE01 mode converter

A compact and broadband TM
01
-TE
01
mode converter is designed for high-power microwave (HPM) transmission system. For the compact design, a 9-fold helical corrugated waveguide (HCW) is introduced to realize the direct conversion of the TM
01
mode into the TE
01
mode. To further increase bandwidth and power capacity, Fourier expansion is applied to HCW and the conventional sine-shaped HCW is improved to U-shaped HCW with larger ridge area. After optimizing the structure parameters, the simulation results show that the maximum conversion efficiency of the proposed TM
01
-TE
01
mode converter reaches 99.6% at 8.6 GHz and a bandwidth of 15.7
^%
with a conversion efficiency of over 95% (central frequency 9 GHz). Moreover, the overall longitudinal and transverse dimensions of the mode converter are less than 4 wavelengths and the power capacity reaches 3.53GW. The results show the excellent performance of this mode converter and provide a guidance for compact mode converter with high-power capacity.