Multilayer tri-band BPF embedded in low temperature co-fired ceramics for modern wireless applications

This paper presents a novel, compact size tri-band BPF embedded in a low temperature co-fired ceramics designed to produce three passbands for UMTS and WiMAX applications. The packaged tri-band BPF center frequencies are 2.1 GHz, 3.5 GHz and 5.8 GHz. A design methodology as well as design guidelines are proposed based on stepped-impedance coupled resonators to produce tri-section stepped-impedance resonators for the second and third passbands and dual-mode resonators for the first and second passbands. This novel tri-band BPF is simulated, optimized and verified. The proposed filter provides better size reduction and at the same time performs superior enhancement in insertion losses and keeps adequate passbands compared to other published tri-band packaged filters.