TM01-TE11 mode converter of tri-bend circular waveguides

The structure of tri-bend circular waveguides was studied by theoretical calculation, theoretical design and numerical simulation. The TM01-TE11 conversion efficiency formula were derived and the condition for the highest conversion efficiency was obtained. Two mode converters of this kind with an inner radius of 3.0 cm and 3.5 cm were analyzed. The conversion efficiency exceeded 99.64% and 98.62% at 4.25 GHz and its bandwidth of power conversion efficiency exceeding 90% reached 9.88% and 12.71%, respectively. The simulation verified the theoretical design.