A 77-GHz CMOS on-chip bandpass filter using slow-wave stepped-impedance resonators

This paper presents the design and implementation of a 77-GHz millimeter-wave on-chip bandpass filter using a 0.18-μm standard CMOS process. The concept of quarter-wave length stepped impedance resonator (λ/4 SIR) is utilized in the design of improving stopband characteristics. It also can reduce the length of the uniform transmission line. From the structure of the open-circuited dual-behavior resonators (OC-DBRs), this produces one passband with transmission zeros on both sides. In addition, the EBG slow-wave structure is used to reduce the length of open stubs. It can further reduce the component dimension. Compared with the original stub filter, the size of the proposed filter with slow-wave SIR has a smaller size with the size reduction of 40% when they are operated at same resonance frequency. The size of the proposed filter is 0.5 × 0.655 mm².