Circuit synthesizable guaranteed passive modeling for multiport structures

In this paper we present a highly efficient algorithm to automatically generate circuit synthesizable dynamical models for passive multiport structures. The algorithm is based on a natural convex relaxation of the original nonconvex problem of modeling multiport devices from frequency response data, subject to global passivity constraints. The algorithm identifies a collection of first and second order passive networks interconnected in either series or parallel fashion. Passive models for several multiport structures, including Wilkinson type combiners, power and ground distribution grids and coupled on-chip inductors are provided to corroborate the theoretical development and show efficacy of the implemented algorithm. To demonstrate the practical usage of our algorithm, the identified models are also interfaced with commercial simulators and used to perform time domain simulations while being connected to highly nonlinear power amplifiers.