Design and Fabrication of an Extremely Broadband Waveguide Twist Based on Gielis Curves

This article introduces a novel method for designing extremely broadband compact waveguide twists using supershapes. The proposed design features a double-ridge waveguide (DRW) twist consisting of two straight DRWs and a compact supershaped twist section with less than one quarter wavelength thick. The design takes into account CNC machining constraints and achieves an extremely wide bandwidth. To verify the design, a 90° waveguide twist was fabricated and measured. The measured results are in acceptable agreement with the simulations and show a low insertion loss of 0.11 dB and a return loss of more than 18.6 dB over a very wideband from 6.77 to 17.44 GHz. The proposed design addresses the increasing demand for compact, low-loss, and broadband waveguide twists and shows superior performance over conventional designs in terms of bandwidth, ease of fabrication, and compactness.