Broadband Contactless 90° Waveguide Transition With a U-Shaped Choke Groove

This letter presents a broadband 90° bent waveguide transition that is suitable for the
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-plane split-blocks technique. In this transition, imperfect metal connections will not cause unacceptable transmission loss by employing a novel U-shaped choke groove and a groove gap waveguide. Such contactless waveguide transitions are advantageous as they allow for easy interconnection and packaging of millimeter-wave and terahertz circuitry. A 90° bent waveguide operating over the WR-4.3 waveguide frequency band (170–260 GHz) is designed, and the transition with a different air gap between the top and bottom parts is measured. The measured results show that the transmission losses are about 0.2 dB with good consistency.