Design and analysis of Piezoelectric MEMS Varactor loaded on QMSIW filter for 5G Communication

This paper presents the design and simulation of Piezoelectric MEMS varactor for 5G communication. The piezoelectric MEMS varactor is utilized for the tuning of the RF structure in the form of Quarter Mode Substrate Integrated Waveguide (QMSIW). Piezoelectric MEMS varactor is positioned above the QMSIW resonator. The QMSIW is a second order resonator built on the high resistive silicon substrate having dielectric constant 11.7 having a thickness of 254 µm. Piezoelectric MEMS varactor is designed for Aluminium Nitride and Lithium Niobate as the piezoelectric material. Aluminium Nitride based varactor is actuated to – 11.8 V compared to – 20 V for Lithium Niobate based varactor to achieve a displacement of 450 μm displacement. With this upward displacement of the piezoelectric diaphragm, the resonant frequency bandwidth of the QMSIW filter vary up-to 800 MHz from 29.4 GHz to 30.2 GHz. The transmission zero to the right side of the passband shifts itself towards the passband by 1 GHz, making the passband narrower. Thus, making the structure suitable for 5G Communication.