Compact LTCC Bandpass Filter (BPF) with High Frequency Selectivity Based on Mixed Electric and Magnetic Coupling

In this paper, based on mixed electronic and magnetic coupling (E-M coupling) structures and miniaturized resonator units, a compact low-temperature co-fired ceramic (LTCC) bandpass filter at 2.48 GHz is proposed. Due to the E-M coupling and source-loading structures, three transmission zeros (TZs) are introduced. Simulation results show that the insertion loss of the BPF is 1.66dB and bandwidth is 220MHz (2.375-2.595GHz). The size of the BPF is 2.6mm×2.4mm×0.7mm (0.060λg×0.055λg×0.016λg).