Micromechanical Process Compatible Twisted Waveguide Fixed Phase Delay Line Operating at Full WR-7 Band

Fixed phase delay lines are devices that change the phase of transmitted signals and have important applications in fields such as radar, communication system, and instrumentation. In this paper, a terahertz fixed phase delay line based on twisted waveguides is implemented, achieving a fixed phase shift of 180° in the 110 GHz-170 GHz frequency band (full WR-7 band). It supports micromechanical milling process and has an insertion loss of less than 1.6dB, with in-band phase flatness within ±10°.