A Compact 1.8–3.0 GHz IPD-Based Wideband Bandpass Filter for System-on-Package

This letter presents the design of a compact 1.8 GHz - 3.0 GHz wideband bandpass filter which employs a variety of transmission zeros for high selectivity. The bandpass filter is made by integrated passive device (IPD) technology on GaAs (Gallium Arsenide) substrate. The chip size of fabricated bandpass filter is significantly reduced to 2.2 mm × 1.3 mm × 0.1 mm. The high selectivity is achieved by utilizing LC resonators to provide transmission zeros. An experimental circuit results show good agreement with the electromagnetic simulation results. The bandpass filter possess low in-band insertion loss and high out-band suppression. The insertion loss (IL) is less than 3 dB over the pass band, out-band attenuations are more than 34 dB and 33 dB in 1.2 GHz and 3.7 GHz respectively. The experimental results exhibit that the filter has good potentials in high-resolution miniaturized microwave communication systems and is well suited for low-cost high performance system-on-package S-band radio front ends.