Dual-band BPF embedded in multilayer low temperature co-fired ceramics (LTCC) for WiMAX applications

This paper presents a novel, compact size dual-band BPF embedded in a low temperature co-fired ceramics (LTCC) designed to produce two passbands for WiMAX applications. The dual-band BPF center frequencies are 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 dual-band response. Two techniques of designing dual-band BPF are investigated and compared; using edge-coupled striplines and broadside-coupled striplines. The broadside-coupled technique is found suitable for size reduction and better performance. This novel dual-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 dual-band packaged filters.