A MICROWAVE FILTER FABRICATED ON THE LEAD FREE PIEZOELECTRIC SUBSTRATE USING THE INTERDIGITAL CAPACITOR AND BONDING-WIRE INDUCTOR

摘要

In this letter, a lumped-element bandpass filter (BPF) fabricated on the high-dielectric constant piezoelectric substrate using the interdigital capacitor and the bonding-wire inductor is designed and implemented. The lead-free piezoelectric substrate of Bi{sub}0.5Na{sub}0.5TiO{sub}3 (BNT) ceramics prepared by a conventional solid-state reaction method and sintered at temperatures 1100℃ was used as substrate. The resonant frequency could be easily controlled by varying the lengths of silver bonding wire. The design procedure using the analysis of different bond-wire lengths of silver wire is described in this work. A lumped-element BPF with a central frequency at 0.9 GHz and a fractional bandwidth of 31.53% are fabricated and measured using the network analyzer.