Liquid crystal transmissive metasurfaces as electrically tunable millimeter-wave transmission modulators

We investigated liquid crystal (LC) transmissive metasurfaces that can be used as electrically tunable millimeter-wave (MMW) modulators. The examined device was composed of orthogonally combined wire-grid (OWG) metal electrodes. The transmission properties of the OWG cell were evaluated using electromagnetic field simulations. The simulation results demonstrated the occurrence of a dual resonant band based on magnetic resonance. A prototype OWG cell was fabricated to examine the actual transmission properties under voltage application. The obtained transmittance characteristic curve exhibited the same trend as the simulated results. A maximum transmittance change of approximately 50% and relatively short response time equal to or less than 3 s were obtained for the prototype cell. The proposed LC MMW metasurface can be utilized as a tunable dual-mode transmissive modulator, exhibiting two resonant modes within the V-band.