Design of LTCC Quintuple-mode Dual-band Filter with miniature

A structure of quintuple-mode resonator and a method of realizing dual-band filter based on LTCC（low temperature co-fired ceramic） technology are proposed. The quintuple-mode resonant structure is designed by two triple-mode resonators proposed before. The feasibility of the quintuple-mode resonant structure is verified both in theory and in practice by the odd even mode analysis and the weak coupling simulation. The dual-band filter is realized by the proposed quintuple-mode resonator. The harmonic is suppressed and the filter is miniaturized by the ways of source-load coupling and connecting the terminal short circuit capacitor to realize open circuit structure. The filter is modeled based on the LTCC process. The method of three-dimensional integration is adopted,and the internal circuits are arranged by stacking technology,so as to achieve miniaturization. By using this method,a dual-pass filter with pass-band 3.95 GHz ～ 4.25 GHz and 6.80 GHz ～ 7.60 GHz is designed. The return loss is better than 10 dB,and the insertion loss is less than 2 dB in pass band,the size is only 4.2 mm×4.8 mm×1.5 mm,the evaluation results show a good match between the sample test with the full wave electromagnetic simulation.