A thermally activated VO2-based attenuator with SRR structure

To meet the requirement of blocking unwanted or interfering signals in modern communication systems, wideband phased-array antenna systems, and 5G mobile communications, we proposed a radio fre-quency (RF) attenuator based on a split ring resonator (SRR) that used a phase change material (PCM) vanadium dioxide (VO2). The SRR was transformed into a thermally activated attenuator by depositing a 120 nm VO2 thin film between the two gold rings of an SRR. We achieved an obvious attenuation (about 18 dB) at 3.55 GHz when the temperature increased from room temperature to 100 & DEG;C due to the dielec-tric constant drop and wide resistance variation of VO2 thin film during the phase change process. At the same time, we observed a hysteresis property on the S parameters due to the resistance hysteresis of VO2 during the heating and cooling process both in the theoretical and experimental results. Finally, consid-ering the resistance of the VO2 thin film between two gold rings, we proposed a modified lumped RLC circuit model for the VO2-based RF attenuator.& COPY; 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

In this paper, a RF attenuator based on a split ring resonator and phase change material VO2 is proposed. By controlling the phase change process and resistance variation of the VO2 thin film, significant attenuation at a specific frequency is achieved. Meanwhile, the resistance hysteresis of VO2 at different temperatures is studied by designing a suitable circuit model.