Wideband On-Chip Bandpass Filter in GaAs IPD Technology With High Frequency Selectivity

This letter proposes a wideband high selective on-chip bandpass filter (BPF) implemented on GaAs substrate integrated passive device (IPD) technology. Introducing lumped elements outside the resonator and coupling them with the resonator can introduce three transmission zeros (TZs). These three TZs are elaborately generated to enhance frequency selectivity and improve stopband rejection level. Moreover, it leverages high-quality-factor lumped elements, significantly bolstering the circuit’s resonance capacity. When wideband performance is necessary, using the Chebyshev principle for design allows achieving the desired bandwidth. To validate this design approach, a BPF centered at 3.8 GHz was simulated, fabricated and measured using GaAs IPD technology, showing promising applications in integrated circuit designs.