一种L～E波段的混合型射频MEMS单刀双掷开关设计

针对传统RF MEMS单刀双掷(SPDT)开关应用存在频段低、插入损耗高、隔离度低等问题，设计了一种混合型SPDT开关，通过在一条通路上设置接触式开关和电容式开关，实现了在L～E频段下的低插入损耗和高隔离度。通过设计蛇形上电极结构，降低了上电极的弹性系数，进而降低开关上电极下拉所需的驱动电压。采用HFSS仿真软件对混合型SPDT开关的射频性能参数进行了优化，并利用COMSOL对开关的蛇形上电极进行应力-位移分析。仿真结果表明，在DC～90 GHz的频段下，SPDT开关的插入损耗小于1.5 dB@90 GHz,隔离度大于52 dB@67 GHz、29 dB@90 GHz。此开关适用于无线通信系统、雷达系统和仪器测量系统等对工作频段要求高的领域内。

Design of a L-E Band Hybrid SPDT RF MEMS Switch

Aiming at the problems of low-frequency band, high insertion loss, and low isolation in the application of traditional RF MEMS SPDT switch, a hybrid SPDT switch was designed. By setting the contact switch and capacitive switch in one path, low insertion loss and high isolation in the L-E band area unit were achieved. By coming up with the snake-like upper electrode structure, the elastic constant of the upper electrode was reduced, and therefore the driving voltage needed to drag down the upper electrode of the switch was reduced. HFSS simulation software system was employed to optimize the RF performance parameters of the hybrid SPDT switch, and COMSOL was employed to conduct stress-displacement analysis on the snake-like upper electrode of the switch. The simulation results show that, within the waveband of DC-90 GHz, the insertion loss of the SPDT switch area unit is lower than 1.5 dB @90 GHz, and the isolation is higher than 52 dB @67 GHz, 29 dB @90 GHz. This switch can be used in wireless communication systems, radar systems, instrument measurement systems, and other fields with high requirements for working frequency band.