Analytical Framework and Component Optimization for Minimizing Harmonic Distortion in DC-DC Small-Signal Converters

This paper introduces new methods of a mathematical framework for analyzing and reducing harmonic distortion in small-signal DC–DC converters. Traditional methods often depend on large passive components or trial-and-error tuning, which can be costly and lack precise predictive power. In contrast, this work defines a harmonic reduction coefficient (Δ), derived analytically from small-signal transfer functions, serving as a design tool to quantify and minimize harmonic content. Closed-form formulas for the resonant frequency and Δ are developed for Buck, Boost, and Buck–Boost converters operating in continuous conduction mode (CCM). The proposed approach enables the optimal selection of passive components to effectively suppress second-harmonic distortion, eliminating the need for additional filtering hardware. Simulations confirm the theoretical findings, showing significant improvements in total harmonic distortion (THD). Overall, the Δ-based design method offers a practical and versatile tool for enhancing converter performance in sensitive applications, including radar systems, audio equipment, and renewable energy interfaces.