Equivalent circuit design of compacted K-band bandpass filters by standard 0.18-µm CMOS technology

A method based on equivalent circuit is presented to design a class of compacted millimeter wave bandpass filters in standard 0.18-mum CMOS process. Thin film microstrip is properly constructed on the lossy silicon substrate to realize small insertion loss. Using broadside-coupled scheme, thin film microstrip bandpass filters are designed and fabricated. Equivalent circuit model and theoretical network analysis are given to explain the performance of the suggested filters. Design procedures for one-stage and multi-stage filters are proposed. Meandering transmission lines are properly constructed to miniaturize the chip size. A class of compacted K-band bandpass filters is implemented. Their measured results agree with the design results very well.