Miniaturized and Wideband Lumped Filter Using LTCC Integrated Package

A miniaturized multilayer lumped-element bandpass filter (BPF) based on low-temperature co-fired ceramic (LTCC) with a central frequency of 50MHz is proposed. The filter is constructed with high-Q spiral octagonal inductors and vertically-interdigital-capacitors (VICs). The overall size of the proposed BPF is only 26 mm × 15 mm. Meanwhile, the BPF achieved a wideband fractional bandwidth (FBW) of 30% and a low in-band insertion loss of 0.88 dB as well. This is of great significance for the communication application of very-high-frequency (VHF) band.