Circular waveguide TM₀₁-rectangular waveguide TE₁₀ mode converter

A compact high power microwave circular waveguide TM01-rectangular waveguide TM10 mode converter was designed to realize the high efficiency mode conversion and high power capacity. The simulation result shows that the mode conversion efficiency with a center frequency of 9.7 GHz is more than 99.99%, the return loss is smaller than -40 dB， and the bandwidth with conversion more than 90% exceeds 0.4 GHz. The frequency of the mode converter is tunable for 9.2-10.1 GHz (the efficiency of the mode conversion exceeds 99%) by changing the length of the short circular waveguide. The chamfer angle between the input circular waveguide and coupling circular waveguide can depress the field enhancement and improve the power capacity. The max surface E-field is 100 MV/m with an incident power of 0.7 GW.