A bandpass filter using LTCC System-on-Package (SOP) Technology

LTCC System-on-Package (SOP) Technology is presently the most effective method for realizing the miniaturization of wireless front-end applications. In this paper, the development of highly integrated three-dimensional (3-D) filter solutions in multilayer low temperature co-fired ceramic (LTCC) technologies is presented for compact, low-cost wireless frontend modules utilizing system-on-package (SOP) technology. An asymmetrical dumbbell-shaped capacitor and wideband circuit design method was used to improve the filter characteristic. The embedded filter demonstrate an excellent performance (1L <; 1 dB, 3 dB BW 5 ≥ 27% at the centre frequency of 1.3 GHz) and great potential for high level of 3-D integration in wireless system. The BPF circuit is based on the quasi-lumped filter topology and some broadband technology was adopted. It has been simulated and optimized by Ansoft HFSS. The measured results agree very well with the full-wave electromagnetic designed responses.