Design, Simulation, and Characterization of Variable Inductor With Electrostatic Actuation Fabricated by Using Surface Micromachining Technology

In this paper, a new variable inductor with electrostatic actuators was proposed and was fabricated using surface micromachining microelectromechancal systems (MEMS) technology. The variable inductor consists mainly of planar spiral inductor, the shielding metal plate above the spiral inductor, and the electrostatic-driven capacitive actuators. In order to enhance the tuning range of the variable inductor, the shielding metal plate has adopted electroplated Ni₈₀Fe₂₀ Permalloy as the “magnetic core” of the variable inductor. The fabricated variable microinductor was tested and characterized. The measured results indicated that the variable inductor had good performance at high frequency and the tuning range of the variable inductor was 77.8%. The effect of Ni₈₀Fe₂₀ Permalloy metal plate on the inductance of variable inductor was also discussed.