Design of a compact bandpass filter with multi-coupled stepped impedance resonators using LTCC technology

摘要

A multilayer LTCC bandpass filter is proposed in this paper. The proposed filter consists of two pairs of improved stepped impedance resonators (SIR''s). The improved SIR''s have realized multi-coupling which makes the filter more compact. In addition, due to the multi-coupled SIR''s, two transmission zeros are introduced to improve out-band characteristic of the filter. This filter has a central frequency of 6GHz with a bandwidth of 1GHz, the insertion loss is less than 1.5dB and the overall size is 2mm∗2.2mm∗0.9mm.