High Selectivity Millimeter-Wave On-Chip Band-Pass Filter With Semi-Lumped Dual-Mode Resonator by Using GaAs Technology

In this letter, a high selectivity millimeter-wave on-chip bandpass filter is presented. In contrast with the conventional filter with multi-order resonators, the semi-lumped dual-mode resonator with minimal order can be employed to achieve three transmission zeros (TZs), which can maintain high selectivity and compact size. Furthermore, another two TZs are introduced to improve the attenuation level of the upper stopband by two capacitive loading stubs. A chip sample is fabricated with Gallium Arsenide processing with a size of ${0}.{75}\times {0}.{43}$ mm2. The measurement results show that the center frequency is 33.5 GHz, the fractional bandwidth is 62.7%, and the insertion loss is 1.06 dB. Good agreements are observed between the simulated and measured S-parameters.