A high coupling factor transformer at 2.4 GHz in 0.18 μm CMOS

A high coupling coefficient transformer was designed for standard 0.18 μm CMOS technology. By changing the transformer track spacing and using varying track spacing areas, this study achieved a high coupling strength, which was applied to a 2.4 GHz transformer. This process obtained a quality factor (Qp) of approximately 8.5, a coupling coefficient (K) of approximately 0.85, and a chip area of 0.388×0.324 mm².