Leakage current effect on fixed and tunable solenoid RF MEMS inductors

This paper investigates the performances of fixed and tunable solenoid RF MEMS inductors for two silicon substrates: regular and etched. We have modeled the current density distribution in silicon substrates and then in NiFe plate using FEM numerical tool. Moreover, we have studied the inductors performances in responses of frequency variation from 100 MHz to 30 GHz. The best quality factor and resonant frequency values are respectively Qmax = 19 and Fres = 15 GHz when substrate leakage current is reduced. In addition, the obtained tuning range increases and reaches Tr = 132.8% at 10 GHz instead of Tr = 96.8% at 5 GHz when the silicon substrate is etched.