Compact circular waveguide TM ₀₂ ‐TE ₁₁ mode converter

Abstract

Using the concept of a metallic cylinder and a linearly tapered metallic baffle loaded in a circular waveguide to convert TM02 circular waveguide mode into TE11 circular waveguide mode, a novel and compact circular waveguide TM02‐TE11 mode converter is designed, fabricated, and measured. The detailed design methods, experimental setups and results are presented in this study. Simulation results show that the purity of output fundamental TE11 mode of the converter exceeds 99.6% for an operating frequency of 9.4 GHz and the power capability is as high as 1.66 GW, the mode conversion efficiency is more than 90% from 9.23 to 9.83 GHz band and the relative bandwidth is about 6.38%. A good agreement between measurements and simulations is observed. The circular waveguide TM02‐TE11 mode converter has many advantages, such as the simple structure, coaxial input and output, high conversion efficiency, proper bandwidth and high power‐handling capability. When used in the field of high power microwave transmission and radiation, the proposed converter could significantly enhance the compactness of all the radiation systems.

A Method for Accurately Characterizing Single Overmoded Circular TM01-TE11 Mode Converter

“…The device under test (DUT) is designed to achieve 1GW peak power handling capacity and 98.5% power conversion efficiency within 14.6～15.4GHz, which measures 20cm long by 3cm inner waveguide diameter with an overmoded ratio of about 1.5. To characterize single target mode converter, our idea is to employ a TM 01 mode generator A and a TE 11 mode generator B to conduct a "TM01A+Mode Converter+TE11B" measurement [19], as shown in Fig. 4, then to remove the TM01A and TE11B mode generators' influence from the composite measurement results through de-embedding calculation [20] for the net Sparameters of the target TM 01 -TE 11 mode converter.…”