Design of a TM01-TE01 transmission line for high-power microwave applications

In this paper, we report the design methods and numerical results for a kind of high-power microwave (HPM) circular waveguide transmission line, which has a 90-degree bend to change the wave propagating direction for certain purposes, and meanwhile, also acts as a TM₀₁-TE₀₁ converter, transforming the HPM sources generating TM₀₁ mode into the TE₀₁ mode. A type of mode conversion sequences, i.e. TM₀₁-TE₁₁-TM₁₁-TE₀₁, is proposed. In the sequences, a 90-degree-bend circular waveguide TM₁₁-TE₀₁ mode converter is adopted to change the wave propagating direction. Besides, compact, linear TM₀₁-TE₁₁ and TE₁₁-TM₁₁ mode converters are designed to perform the mode conversion from TM₀₁ mode to TM₁₁ mode. The transmission efficiency of the designed transmission line is 97.9% at 3.5 GHz, and the bandwidth for efficiency>;90% is 5.3%.