Wideband lumped scalable modeling of monolithic stacked transformers on silicon

A lumped model for monolithic stacked transformers on silicon is presented. It employs a novel topology that combines tbe simplicity of lumped models aud the accuracy of distributed networks. Model parameters are calculated by means of closed-form expressions using geometrical and technological data. The accuracy of the proposed model is demonstrated by comparing simulations with on-wafer experimental measurements of several stacked transformers. The self-resonance frequency is used as a figure of merit to test the performance at very high frequencies. Moreover, the geometrical scalability is verified employing the S-parameters of transformers with different layout parameters and over a wide frequency range.