Modeling and Lumped-Element Extraction of PCB-Based Laterally Coupled Coplanar Transformers

In this paper, we present a comprehensive analysis of concentric and interleaved coplanar transformer models, focusing on key performance parameters such as self-inductance, resistance, mutual inductance, and interwinding capacitance. These parameters are used to develop a lumped-element model that accurately represents the behavior of a coplanar transformer. We propose a universal method based on FEM simulations to extract each parameter value, while the validity of the lumped model is verified by comparisons with measurements obtained from printed circuit board (PCB) transformers and HFSS simulations.