A Broadband Butterfly-Shaped 90° Waveguide Twist for Rapid Design

A broadband 90° waveguide twist operating in millimeter wave (mm-wave) is proposed and verified in this letter. Excellent performance is obtained by a novel butterfly-shaped waveguide, which has the advantage of simple construction and can be designed rapidly for different frequencies when compared with conventional ones. Two waveguide twists used for WR10 and WR4.3 rectangular waveguides are fabricated by CNC manufacturing. The proposed design exists broadband characteristics, with 37% and 42% relative bandwidth by the measured results in WR10 and WR4.3 frequency bands. The measured results also show that the return loss is better than 20 and 15 dB from the frequency range of 75–110 and 170–260 GHz, respectively, and the in-band insertion loss is around 0.1–0.2 and 1 dB.