MI017 - Integrated microwave frequency tunable bandpass filter using barium strontium titanate varactors

Abstract

A bandpass filter for the frequency range of 6¿9 GHz, based on tunable interdigital BST varactor is presented. This paper reports the processing steps required to obtain a functional and integrated bandpass filter, which include: via drilling and filling purpose, dielectric deposition, chromium/gold deposition and copper electroplating. Microwave measurements reveal an insertion loss range between 7¿11 dB, a 20 dB rejection band, a bandwidth of less than 500 MHz, and 1.73 GHz of frequency tunability.