Modeling and measurements of novel high k monolithic transformers

This paper presents modeling and measurements of a novel monolithic transformer with high coupling k and quality factor Q characteristics. The present transformer utilizes a Z-shaped multilayer metalization to increase k without sacrificing Q. The new transformer has been fabricated using Motorola 0.18 micron copper process. A simple 2-port lumped circuit model is used to model the new design. Experimental data shows a good agreement with predicted data obtained from an HFSS software simulator. An increase of about 10% in mutual coupling and 15% in Q has been achieved. For a modest increase in k of about 5%, Q can be increased by up to 20%.