A simple approach to closed-form Green's functions of microstrip structures

Abstract

The spectral-domain Green's functions for open microstrip structures are expressed in terms of pole-residue expressions by a vector-fitting technique after extracting the quasi-dynamic images. After the inverse Hankel transformation, the spatial Green's function takes the form of summing up a series of Hankel functions plus the quasi-dynamic exponential terms. This simple approach avoids the difficulty of manually extracting the surface-wave poles required in the traditional discrete complex image method (DCIM), while retaining the high accuracy of the closed-form expressions in the near-field region. The numerical results for the Green's functions of one-layer and two-layer structures verify the validity and efficiency of this approach. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 435–438, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20846