Determination of the complex permittivity values of planar dielectric substrates by means of a multifrequency PSO-based technique

In this paper, an innovative technique for the determination of the dielectric properties of planar substrates is presented. Starting from a set of impedance measurements performed on a section of a microstrip transmission line built on the planar dielectric substrate under test, the proposed technique formulates the reconstruction problem in terms of an optimization one successively solved by means of an effective stochastic algorithm. Such a method allows one the reconstruction of the permittivity values at multiple frequencies by simply using a vector network analyzer and a standard calibration procedure for the impedance measurement. The results of some representative experimental tests are shown for a preliminary assessment of the effectiveness of the proposed approach. (c) The Electromagnetics Academy - The final version of this article is available at the url of the journal PIER M: http://www.jpier.org/PIERM/pier.php?paper=09112901