A Miniaturized Helical LTCC Bandpass Filter with Helix Resonator Structure

In this paper, a compact helical LTCC bandpass filter based on helix resonator structure is proposed, which obtains high frequency selectivity and low insertion loss. Low-temperature cofired ceramic technology (LTCC) is one of the most efficient ways to realize the miniaturization of the proposed filter. The mixed electric and magnetic coupling (EM Coupling) is introduced to generate the transmission zeros (TZs). The simulation results of the filter shows the insertion loss is less than 1.68 dB and bandwidth is 0.097 GHz, from 0.927GHz to 1.024 GHz. The return loss at center frequency is 36dB, with the size of 4.93mm×2.4mm×1.65mm.