Miniaturized High-Selectivity High-Resistivity-Silicon IPD Bandpass Filter Based on Multiple Transmission Paths

In this letter, a miniaturized bandpass filter chip is designed and implemented on high-resistivity-silicon (HRS) integrated passive device (IPD) technology. The filter is designed into a three-path topology, which can generate multiple transmission zeros to achieve a high roll-off rate at the passband edge and good rejection in a very wide stopband. For validation, the filter chip operating at 5G N77 frequency band is fabricated with a compact size of $1.1\times0.7$ mm2 on IPD technology. Measured results show an in-band insertion loss of smaller than 1.7 dB and a wide stopband from 5.39 to 31.5 GHz.