Passivity Enforcement of S-Parameter Models Using Singular Value Decomposition and Time-Domain Quality Metrics

This paper presents a singular value decomposition (SVD)-based algorithm for enforcing passivity in interpolated and extrapolated S-parameter models. The method introduces minimal perturbations to ensure passivity while preserving model fidelity. A passivity quality metric, based on time-domain pulse response comparison, quantifies the enforcement impact. Validation on Through_20GHz.s2p and Simulated_Microstrip_6In_560hm.s2p datasets confirmed the method’s effectiveness, with maximum $\Delta V$ values of 0.4304 mV (Good) and 6.3353 mV (Acceptable). The results demonstrate reliable passivity enforcement with controlled deviation. The results obtained in this article can be used by the engineers in the design of the microwave and the antenna systems.