Wireless communication systems actively use sub-6 GHz spectrum and require innovative decisions for switching microwave signals. A promising solution is switches fabricated using microelectromechanical systems (MEMS) technology. An important characteristic of a MEMS switch is the ratio of capacitances in the closed and open states. Typically, it does not exceed 10 and provides no required switching effect. An efficient method for increasing the capacitance ratio is to apply an intermediate electrode over the dielectric coating of a transmission line. The work is devoted to the MEMS switch with an intermediate electrode. Its performance is considered depending on the electrode size, dielectric layer material and contact resistance. In the frequency range of 3.4–5.0 GHz, the switch provides a capacitance ratio of 146 using a 200 µm long electrode and silicon dioxide. Isolation and insertion loss are of 19.5–21.5 and 0.13–0.15 dB given that the contact resistance is not higher than 0.1 Ohm.
Morozov et al. (Mon,) studied this question.