Miniaturized High-Selectivity Bandpass Filter With Wide Stopband Based on Through-Glass-Via IPD Technology

In this letter, a miniaturized high-selectivity bandpass filter with wide stopband is proposed based on through-glass-via (TGV) integrated passive device (IPD) technology. Four LC resonators are used to construct the filter, and each resonator can generate a transmission zero with independently adjustable position, which facilitate the realization of high skirt selectivity. Moreover, additional coupling path is introduced to create another transmission zero at the higher frequency of the stopband, extending the upper stopband frequency range. For verification, a prototype filter at 5G N77 band was manufactured in TGV- IPD technology. The filter has a compact size of
$0.9\times 0.45$
mm2. The measured in-band insertion loss is less than 1.15 dB and the 20-dB rejection band frequency ups to
$4.38~{f}_{{0}}$
.