This letter presents novel high power and reliable radio frequency (RF) microelectromechanical systems switches with single-pole single-throw (SPST) and single-pole triplethrow (SP3T) configurations. An in-plane movable structure with a single layer is made using a simple standard silicon-on-insulator process, which greatly reduces the micro-fabrication complexity and cost compared with the previously reported multi-contact switches with out-of-plane movable structures. The SPST switch achieves a uniform current distribution through each contact, thereby increasing the power handling capability of the switch. The SP3T switch is a derivative of the SPST switch with separate individual actuations. The experimental results demonstrate that the fabricated switches have superior RF performances: insertion losses are −0.9 and −1.3 dB at 6 GHz for SPST and SP3T switches, respectively, whereas isolations are better than −29 and −37 dB from dc to 6 GHz for SPST and SP3T switches, respectively. In hot-switching conditions, the SPST switch can handle RF power up to 2 W for 10 million cycles, whereas the SP3T switch is capable of handling an RF power of 1 W for 7 million cycles before failure occurs.

In this paper novel V-shaped and Z-shaped thermally actuated Radio Frequency (RF) MicroElectroMechanical Systems (MEMS) switches are designed and fabricated for the application of smart antennas. The switches are driven by a metal electrothermal actuator, which is able to generate large displacement and high contact force at lower temperatures. The MEMS switches utilizing the parallel beam actuator achieved 8 µm displacement. RF performances are improved by suspending the switching structures 25 µm above the substrate, thereby reducing the loss in the substrate. ON state insertion loss of -0.42 dB at 10 GHz , OFF state isolation of -40 dB at 10 GHz and return loss better than of -20 dB at 10 GHz for bidirectional Z-shaped thermally actuated RF MEMS switch are achieved on low resistivity silicon substrate.

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This letter presents a novel three-state contactless radio frequency (RF) microelectromechanical systems switch for wireless applications. The switch is free from stiction and charge injection issues occurred inherently in contact-type RF MEMS switches, thereby increasing reliability and lifetime. The contactless switch is based on variable capacitance between signal lines and movable grounded electrodes controlled by electrostatic actuator. The movable grounded electrode has the capability to move bidirectionally, and therefore, the switch can change among ON-, OFF-, and deep OFF-states. Thus, additional isolation can be achieved in the deep OFF-state. The RF measurement results show that the contactless switch has a capacitance tuning ratio of 5.25 between OFF-and ON-states, and a higher tuning ratio of 11.18 between deep OFF-and ON-states. In addition, the switch exhibits −3.62 dB insertion loss and −24.43 dB isolation at 2.4 GHz. At 5 GHz, the insertion loss and isolation are −2.95 dB and −20.65 dB, respectively.

In this paper, we report a novel laterally actuated Radio Frequency (RF) Microelectromechanical Systems (MEMS) switch, which is based on a combination of electrothermal actuation and electrostatic latching hold. The switch takes the advantages of both actuation mechanisms: large actuation force, low actuation voltage, and high reliability of the thermal actuation for initial movement; and low power consumption of the electrostatic actuation for holding the switch in position in ON state. The switch with an initial switch gap of 7 µm has an electrothermal actuation voltage of 7 V and an electrostatic holding voltage of 21 V. The switch achieves superior RF performances: the measured insertion loss is −0.73 dB at 6 GHz, whereas the isolation is −46 dB at 6 GHz. In addition, the switch shows high reliability and power handling capability: the switch can operate up to 10 million cycles without failure with 1 W power applied to its signal line.