耦合度可切换的太赫兹分支波导定向耦合器

Terahertz Branching Waveguide Directional Coupler with Switchable Coupling Degree

摘要:

本文提出了一种耦合度可切换的太赫兹分支波导定向耦合器，该耦合器的耦合度可在3 dB和10 dB之间进行切换。通过控制前四条分支表面二氧化钒薄膜的电导率，实现耦合度的切换。仿真结果表明，在180~250 GHz的频率范围内，当二氧化钒电导率为200000 S/m时，耦合度为3±0.6 dB，隔离度与回波损耗大于17 dB；当二氧化钒电导率为10 S/m时，耦合度为10±0.7 dB，隔离度大于18 dB，回波损耗大于20 dB。耦合器在两种耦合状态下均表现出优异的性能，符合设计预期。

Abstract:

This letter proposes a terahertz branch waveguide directional coupler with a switchable coupling degree. The coupling degree is switched by controlling the conductivity of the vanadium dioxide film on the surface of the first four branches. The simulation results demonstrate that within the frequency range of 180~250 GHz, the coupling degree is 3±0.6 dB, and the isolation and return loss exceed 17 dB when the vanadium dioxide conductivity is 200000 S/m. Similarly, for a vanadium dioxide conductivity of 10 S/m, the coupling degree is 10±0.7 dB, while the isolation and return loss are both above 18 dB and 20 dB, respectively. The coupler performs exceptionally well under both coupling states, meeting the expectations in design.