A New Six-Port Transformer Modeling Methodology Applied to 10-dBm 60-GHz CMOS ASK Modulator Designs

This paper presents a new broadband equivalent-circuit model for millimeter-wave transformers on silicon. The model includes a center tap on the primary and secondary, and considers coupling between all segments of the windings. A corresponding methodology to analytically extract the model from electromagnetic (EM) simulations is developed. The broadband model is verified by EM simulations and measurements. Two amplitude modulatable power oscillators with high power efficiency are demonstrated using low-loss transformers. One achieves an output power of 10.4 dBm near 57 GHz with a total efficiency of 23.6%. Applying amplitude-shift keying modulation, their maximum data rate exceeds 2 Gb/s. Simulations of these circuits showed the transformer model performs well in time-domain simulations.