Liquid Crystal Phase Shifter Based on Nonradiative Dielectric Waveguide Topology at W-Band

This paper presents a continuously tunable nonradiative dielectric waveguide (NRD) phase shifter based on liquid crystal (LC) technology at W-band. LC is inserted in the NRD’s dielectric core to obtain tunability. Compared to other dielectric waveguides, which are prone to radiation losses, the NRD is radiation free even at bends and discontinuities. A maximum differential phase shift of 280° was achieved with an electric biasing voltage of ±150 V, accompanied with insertion losses between 2.9 dB to 4.9 dB, resulting in a maximum Figure-of-Merit of 85 °/dB.