Tunable Bandpass Filter Design Using Paraelectric Oxide Single Crystal Substrates

The fixed response frequency of conventional bandpass filters poses challenges in emerging ultra-wideband (UWB) communication systems, where universal radios capable of spanning extremely wide frequency ranges are anticipated.A pivotal enabler for such systems is the development of reconfigurable filters, particularly ultrafast tunable bandpass filters.Among the promising approaches, integrating high-K dielectric crystals offers a means of achieving frequency agility by altering the effective dielectric properties of the propagation medium by changing their position, resulting in a shift in the operational band.In this study, we demonstrate a tunable bandpass filter (BPF) employing a paraelectric oxide single-crystal substrate with ultra-low loss within a passive microstrip filter architecture.Preliminary analysis reveals a resonance band shift from 11.8 to 12.2 GHz, exhibiting high-Q, thus highlighting the efficacy of this approach for frequency reconfigurability in next-generation communication systems.