Constant absolute bandwidth UHF tunable filter using RF MEMS

Abstract

This paper presents the design and the performances of a tunable UHF filter that uses MEMS capacitors arrays. Central frequency of the filter varies from 278 to 385 MHz and can be adjusted by actuating a desired number of MEMS. Thanks to a specific topology and well-chosen input and output tank circuits, the absolute bandwidth varies from 13 to 14 MHz and can be considered as constant.