Low-Voltage and High-Reliability RF MEMS Switch with Combined Electrothermal and Electrostatic Actuation

Area of Science:

• Electrical Engineering
• Materials Science
• Physics

Background:

• Radio Frequency (RF) Microelectromechanical Systems (MEMS) switches are crucial for modern wireless communication.
• Existing MEMS switches face challenges in balancing actuation force, voltage, power consumption, and reliability.
• Novel actuation mechanisms are needed to enhance MEMS switch performance.

Purpose of the Study:

• To develop and characterize a novel laterally actuated RF MEMS switch.
• To investigate the combined benefits of electrothermal actuation and electrostatic latching.
• To evaluate the RF performance, reliability, and power handling of the proposed switch.

Main Methods:

• Design and fabrication of a laterally actuated RF MEMS switch.
• Integration of electrothermal actuation for initial movement and electrostatic actuation for latching.
• Experimental measurement of actuation voltages, RF insertion loss, isolation, and operational cycles.

Main Results:

• The switch demonstrated electrothermal actuation at 7 V and electrostatic holding at 21 V with a 7 µm gap.
• Achieved superior RF performance with -0.73 dB insertion loss and -46 dB isolation at 6 GHz.
• Exhibited high reliability, operating for 10 million cycles without failure under 1 W power.

Conclusions:

• The novel hybrid actuation mechanism effectively combines the strengths of electrothermal and electrostatic methods.
• The developed RF MEMS switch offers excellent RF characteristics, low power consumption, and high reliability.
• This design presents a promising solution for advanced RF applications requiring robust and efficient MEMS switches.