Researches on Frequency-Reconfigurable Metasurface Antennas Based on VO2 Films

Vanadium dioxide (VO2), as a phase change material (PCM), is an insulator at room temperature but can turn into a high-conductivity metallic state when it is excited. Comparing with other controllable devices, it cannot only function from DC to terahertz frequency band, but also manage to achieve low insertion loss, high isolation and nanosecond switching speed. Three examples of VO2-based frequency reconfigurable metasurface antennas are proposed and studied. By integrating VO2 with metasurface cells, the antennas can achieve a large frequency ratio up to 1:1.61 and maintain high gain. In order to switch the operating mode of VO2 easily, a coplanar DC bias circuit with little effect on radiation performance is designed. The feeding parts of three antennas are all taken stepped waveguides with ridges through slots. These proposed VO2-based antennas would be potentially applied in millimeter-wave wireless systems in near future