Micromachined cantilever-type π-type continuous reconfigurable microwave bandpass filter

Abstract

The invention discloses a micro-mechanical cantilever beam type pi type continuous reconfigurable microwave band-pass filter. The micro-mechanical cantilever beam type pi type continuous reconfigurable microwave band-pass filter comprises a planar spiral inductor, two identical MEMS variable planar plate capacitors and two identical MIM capacitors are symmetrically arranged at the left and right sides of the planar spiral inductor in sequence, wherein each MEMS variable planar plate capacitor is connected between a CPW signal wire and a ground wire in parallel while each MIM capacitor is connected with the CPW signal wire in series so as to make up a pi type topological structure with band-pass characteristics. The MEMS variable planar plate capacitors achieve different capacitances based on an electrostatic principle; the upper pole plate of each MEMS variable planar plate capacitor is an MEMS cantilever beam while the lower pole plate thereof is the CPW signal wire, wherein the MEMS cantilever beam stretches across the CPW signal wire, and a drive electrode is arranged near the CPW signal wire; an Si3N4 insulating medium layer covers each of the CPW signal wire under the MEMS cantilever beam and the drive electrode. The filter realizes the continuous tuning for the center frequency and the band width and has advantages of low loss, good out-of-band rejection, wide frequency band tuning and small chip area.

Description

technical field [0001] The invention provides a micro-mechanical cantilever beam type π-type continuous reconfigurable microwave band-pass filter, which belongs to the technical field of micro-electro-mechanical systems (MEMS). Background technique [0002] In modern microwave communication systems, reconfigurable filters have important application and research value in military and civil transceiver components. It greatly reduces the system size in multi-band applications, and can dynamically select and suppress signal frequencies and reduce inter-channel interference according to requirements. Reconfigurable filters include digital reconfigurable filters and analog reconfigurable filters. The former is suitable for tuning of some discrete operating frequencies, while the latter is suitable for tuning of continuous operating frequencies. In filter design, passive inductors and capacitors are the easiest way to implement an on-chip filter. In the design of passive filters...

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Problems solved by technology

However, compared with digital reconfigurable filters, analog reconfigurable filters have a wide range of application prospects but less research

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