Closed form expressions for Green's functions of microstrip structures on a uniaxially anisotropic substrate

Closed form expressions for the Green's functions of a planar microstrip structure on an electrically thin uniaxially anisotropic substrate have been derived. The approach is to first obtain the quasi‐dynamic term and refine its accuracy with a correction term valid for higher frequencies. The quasi‐dynamic term conveys the influence of partial images and includes both transverse and vertical dielectric constants ε rt and ε rz . The correction term, on the other hand, results in an expression that includes ε rz only. Results indicate excellent agreement with exact numerical solution over a significant band of frequencies and over a large range of spatial values. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 13: 161–168, 2003.