Radio frequency microelectro-mechanical system (RF MEMS) switches have received attention due to their higher performances at high frequencies compared with semiconductor-based switches. However, most of the previous MEMS switches used electrostatic actuation, which requires a high actuation voltage and has a low actuation force. Herein, we propose a new hybrid RF MEMS switch for low-voltage and low-power operation that is actuated by the combination of bidirectional thermal actuation and electrostatic holding. The proposed hybrid RF MEMS switch is actuated by the combination of two actuation mechanisms, i.e.: 1) bidirectional thermal actuation of the large force with low actuation voltage and 2) electrostatic holding for low-power consumption. The large actuation force enables high signal isolation at the “OFF” state of the switch because of the high initial gap between the signal line and the contact metal. Also, the bidirectional thermal actuator that enables upward actuation prevents any stiction of the membrane, which enhances both the power handling capability and the reliability of the actuator. In this work, we successfully fabricated the proposed RF MEMS switch and measured both its mechanical characteristics and RF characteristics. The required actuation voltage for the switch is less than 0.3 V for thermal actuation, and the required voltage for electrostatic holding is 15.4 V. The power consumption was measured as 3.24 μJ3.24~\mu \text{J} per switching. Also, we measured the RF characteristics, and the insertion loss of signals was 0.23 dB at 2.4 GHz, and the isolation of signals was 38.80 dB at 2.4 GHz.

中文翻译：

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由双向热驱动和静电保持相结合驱动的混合 RF MEMS 开关


射频微机电系统 (RF MEMS) 开关因其在高频下比半导体开关具有更高的性能而受到关注。然而，以往的MEMS开关大多采用静电驱动，需要较高的驱动电压且驱动力较低。在此，我们提出了一种用于低电压和低功耗操作的新型混合 RF MEMS 开关，该开关通过双向热驱动和静电保持的组合来驱动。所提出的混合 RF MEMS 开关由两种驱动机制的组合来驱动，即：1）具有低驱动电压的大力的双向热驱动和 2）低功耗的静电保持。由于信号线和接触金属之间的初始间隙较大，因此大驱动力可在开关“关闭”状态下实现高信号隔离。此外，能够向上驱动的双向热执行器可防止薄膜出现任何静摩擦力，从而增强执行器的功率处理能力和可靠性。在这项工作中，我们成功制造了所提出的 RF MEMS 开关并测量了其机械特性和 RF 特性。热驱动所需的开关驱动电压小于 0.3 V，静电保持所需的电压为 15.4 V。测得每次开关功耗为 3.24 μJ3.24~\mu \text{J}。另外，我们还测量了射频特性，信号的插入损耗在2.4GHz时为0.23dB，信号的隔离度在2.4GHz时为38.80dB。