Identification of broadband passive macromodels for electromagnetic structures

Purpose - The paper aims to present an overview of techniques for the identification in the frequency domain of reduced order models for distributed passive electromagnetic structures. Design/methodology/approach - Most known approaches proposed in different application contexts are described within a unified framework. Findings - A passive reduced order model of an unshielded twisted pair is fully developed with the combination of vector fitting algorithm and the passivity enforcement via Hamiltonian perturbation. Originality/value - A state-of-the-art picture of the frequency domain identification and passivity enforcement techniques is given, and a test case of actual interest fully analysed.