Electromagnetic Equivalent Models for Printed Circuit Boards Inside a Metallic Enclosure Using a Coaxial-to-Waveguide Transition Calibration

Equivalent models of printed circuit boards (PCBs) are useful to simplify electromagnetic problems by reducing the computational costs of numerical simulations. In this paper, a new procedure for obtaining a simple equivalent model of PCBs inside metallic enclosures is presented. The equivalent model is obtained in two steps: first we precisely characterize the coaxial to waveguide transitions used during measurements by means of an inverse procedure and then during a second inverse procedure, we carry out simulations by concatenating these transitions and the equivalent model and comparing to measurements. The optimized parameters for the equivalent model are: thickness, dielectric constant, and the electric conductivity. Results for a PCB in three scenarios have been obtained by using a sweep and two different optimization techniques. Benefits and drawbacks of the model are discussed. Results indicate that this procedure produces very precise characterization of the equivalent model of PCBs depending on the position and orientation of this device within the enclosure.