A high self-resonant and quality factor transformer using novel geometry for silicon based RFICs

A novel 24-sided concave-convex geometry monolithic transformer that has high self-resonant frequency and quality factor is presented. It is implemented with the top level thick Cu metal and multiple geometrical structures in 0.13 um CMOS mixed-signal 1P6M salicide back-end process. Compared to those with conventional square, hexagonal and octagonal geometry structure, the novel transformer achieves better quality factor, self-resonant frequency and less chip area. The simulation results show that 1.12, 1 and 0.58 GHz improvements in SRF, and 2.4, 0.9 and 0.3 enhancements in quality factor are obtained respectively when compared to typical square, hexagonal and octagonal transformer with the same inductance of the primary and secondary winding.