Design of Miniaturized Broad Stopband Lowpass Filter on GaAs IPD Technology

In this paper, a miniaturized lowpass filter with ultrawide stopband and high stopband suppression level is designed based on the Gallium Arsenide-Based Integrated Passive Device (GaAs-Based IPD) technology. A parallel resonance circuit and series resonance circuit are initially used to achieve a lowpass response. Besides, to reduce the effect of parasitic response, a π-shaped circuit is added to the filter so as to introduce an additional zero, which can effectively widen the stopband bandwidth range and enhance the harmonic rejection level. Compared with conventional distribution lowpass filters implemented by microstrip-line or cavity structure, the proposed IPD process-based design offers advantages such as excellent harmonic rejection capability, compact size, and high integration.