Design and simulation of a variable MEMS capacitor for tunable HMSIW resonator

Abstract

Here, a new design of a variable micro electromechanical system (MEMS) capacitor is introduced to use in telecommunication systems. For the first time, an on-chip MEMS component has been used in the substrate integrated waveguide (SIW) structures to avoid discrete and non-integrated connection problems and high noise levels and affects the operating frequency of telecommunication systems. The behaviour of two capacitors with the fixed-fixed and supported membrane by special spiral arms is analysed and simulated using the finite element method. The MEMS bridges are implemented by a 6 μm gold layer and an air gap of 3 μm. It can be seen that using the new special arms, the movement of the membrane is more uniform than the clamped while the actuation voltage is up to 1.32 V and the tuning range of the capacitor is 29%. Then both the capacitors are placed on half-mode SIW structure and the electromagnetic simulation is done. Finally, the results comparison shows that the frequency tuning range of the MEMS variable capacitor is more significant than the other.

RF MEMS electrostatically actuated tunable capacitors and their applications: a review

“…MBTCs are also utilized in tuning and impedance matching of multi-nuclear magnetic resonance imaging (MRI) coils for diagnosis, screening of bio-samples, and diseases due to their high quality and tunability [45,46]. In addition, they have been recently utilized in tuning microwave circuits, such as half mode substrate integrated waveguide-complementary split ring resonator [47]. The resonance frequencies of 3.9 GHz and 7.35 GHz are tuned to 3.65 GHz and 6.6 GHz, respectively.…”

A new wide tunability MEMS based variable capacitor using two separate electro-static vertical comb drive actuators

“…MEMS-based variable capacitors are used as key building blocks in many wireless communication applications, such as tunable filters, voltage-control oscillators, matching networks and phase shifters [1][2][3][4]. Commercially available solid-state varactors such as p-n junction diodes and Schottky diodes offer wide tuning range, small size and very fast tuning speed [5].…”