Transformer synthesis for VHF converters

This document presents a method to synthesize an air-core transformer with a given inductance matrix. The proposed algorithm is used to design a two-winding transformer for a Φ₂ resonant dc-dc converter operating in the VHF (30-300 MHz) regime. The method realizes the required inductance matrix to achieve proper tuning while trading volume and efficiency. Two sets of transformers were fabricated and the measured results compared against predictions. Using one of the transformers, a 75 MHz isolated Φ₂ converter is constructed and tested. The efficiency of the transformer was verified through thermal measurements to be approximately 94%.