Switching of H11-mode electromagnetic field in oversized circular waveguide

Operation of the microwave switch in a circular waveguide with the principal working mode H₁₁ at the frequency 2800 MHz was studied. Experimental results for different switch designs and traveling wave power values up to 0.5 GW are presented. The switching occurs by the microwave discharge plasma formed in the quarts tube filled with gas. The energy distribution between transmitted, reflected and dissipated waves in a waveguide with permissible H₁₁ and E₀₁ modes during switching process was investigated. Main conditions for effective switching in a regular waveguide when the cross section is close to cut-off one for H₀₁ and E₁₁ modes and in short circuited arm of the same cross section of H-tee interference switch are determined.