Tuning Spring Constant of a Beam for a Promising Reduction in the Actuation Voltage of a V-Band RF MEMS Switch

Abstract

Radiofrequency microelectromechanical system (RF-MEMS) switches are utilized across a broad spectrum of industries, telecommunications, aerospace and smartphone technology.Herein, we proposed a new numerical and simulation analysis approach for spring constant (k) values as the characteristic mechanical parameters of RF MEMSs using the modified energy method (MEM). The proposed RF-MEMS switch was analyzed and simulated using the COMSOL package, and the findings confirmed that the alteration in the position and length (L) of the beams not only diminishes k significantly but also provides actuation-voltage VAC ultrasensitive structures and great concomitance between numerical and simulation k and VAC values. VAC value for the L-dependent numerical k (0.07 N m-1) was calculated to be 1.61 V which was validated with simulation outputs at 0.08 N m-1 and 1.80 V for k and VAC, respectively. Additionally, the switching time (ts), Von Mises Stress (VMS), natural frequency (fn) and mass (m) characteristic mechanical parameters were found to be 25.60 µs, 4.50 MPa, 3118.60 Hz , and0.21 ng, respectively. RF analysis was conducted in HFSS, revealing promising simulation results for the studied RF-MEMS switches. The return loss demonstrates excellent performance, registering better than -1 dB at 46 GHz. Furthermore, the insertion loss is noteworthy, exceeding expectations with values better than -0.7 dB at 46 GHz. Importantly, the isolation is impressive, exceeding -25 dB across the frequency range from 40 GHz to 35 GHz, all achieved with a modest actuation voltage of 1.8 V. This study contributes valuable insights intothe design and application of low-actuation-voltage RF-MEMS switches.

Keywords

• actuation voltage
• modified energy method
• rf-mems
• switching time
• von mises stress