Design of compact packaged switched reconfigurable multi-band BPF using LTCC technology

This paper presents a novel reconfigurable tri-band BPF embedded in a low temperature co-fired ceramics (LTCC) package designed with two-state frequency responses, where tri-band and dual-band bandpass characteristics can be conveniently switched by turning chip scale pin diodes on and off. The filter can operate as a tri-band BPF with center frequencies 2.1 GHz, 3.5 GHz and 5.8 GHz for UMTS and WiMAX applications. On the other hand, it can operate only at 3.5 GHz and 5.8 GHz for WiMAX rejecting 2.1 GHz UMTS signals. The design proposes simple resonance stripline structures integrated with chip pin diodes. Bias circuits are designed and optimized with precisely selected practical lumped components. The proposed reconfigurable filter is simulated and optimized. The filter provides significant size reduction and superior enhancement in insertion losses.