Design of an Ultra-Miniaturized Bandpass Filter Based on Integrated Passive Device Technology

In this paper, an integrated passive device (IPD)-based ultra-miniaturized bandpass filter (BPF) with a center frequency of 2.325 GHz is proposed. Three LC resonators, a grounded capacitor, and a grounded inductor make up the filter. At both low and high frequencies, the grounded capacitance and inductor can each independently influence the transmission zeros (TZs). Two different layouts of the ultra-miniaturized BPFs were fabricated using GaAs-based IPD technology, and the oversize of the proposed BPFs is 1.0 mm×1.5 mm. The simulated and measured results of the proposed filters agree quite well, and provide robust confirmation of the claimed exceptional performance of the IPD BPF in terms of good frequency selectivity, ultra-miniaturized volumes, and wide upper stopband.