Performance Evaluation of Microfluidically Tunable Microwave Filters

Abstract

This paper presents a contribution to evaluating the performances of tunable devices devoted to RF applications. It is based on reconfiguration by fluids of a capacitor/inductor associated in a monolithic substrate. Indeed, the association of two microfluidic passive devices on the same wafer allows us to increase the total frequency response of microwaves structures. The study evokes the presence and displacement of different conductive and dielectric liquids in the structure microchannels. The theoretical analysis concerns the association of microfluidic devices, a capacitor and inductor, in parallel topology. The obtained results show a good agreement between electrical parameters and the microwave response. Furthermore, a significant frequency variation from 370 MHz to 1720 MHz is achieved, with a tuning range that reaches 364.8%. The experimental part exhibits the fabrication and characterization of two structures in order to evaluate the response of microfluidic actuation for two architectures: a pass-band filter (presented in prior work) and a stop-band filter. The obtained results are in good agreement with the modeled behavior and demonstrate a large tuning range for the stop-band filter.

Tunable RF MEMS Inductors for Two-Frequency Bands

“…Integrated inductors are essential components in modern RF circuits and have been studied in several recent works, [1], [2], [3], [4], [5]. In the early development of variable inductors, switchable inductors were the first design choice as a means of varying inductance values.…”