Wideband Rectangular TE10 to TE n0 Mode Converters for Terahertz-Band High-Order Overmoded Planar Slow-Wave Structures

摘要

The technique of mode conversion between rectangular TE10 and TEn0 (n = 2, 3, ...) modes is studied in this article. The mode conversion was mainly realized by coupling apertures. To compensate for the junction discontinuity and, thus, enhance the performances, rectangular septa were introduced in the mode converters. Rectangular recesses were added to suppress the potential competing modes. As two examples, the design of rectangular TE20 and TE50 mode converters operating in the terahertz band is presented in this article. To verify the design, two identical rectangular TE20 mode converters joined back-to-back were manufactured by nanocomputer numerical control (CNC) machining and the performances of the converters were characterized by using a vector network analyzer. The measured transmission coefficients were in good agreement with the simulated ones and showed a good flatness response with a 3-dB bandwidth of similar to 70.7 GHz (220.0-290.7 GHz). The average measured value of S-21 was about -2.0 dB and the in-band port reflection S-11 was around -10.0 dB.