A Closed-Form Spatial Green's Function for the Thick Microstrip Substrate: The Meshless Interpolation Approach.

In this paper the Green's functions (GFs) of a thick microstrip in the spatial-domain is computed based on expanding the corresponding spectral-domain functions over inverse quadric (IQ) radial basis functions (RBFs). The scattered data interpolation ability of RBFs is exploited for efficient sampling of the Sommerfeld integration path (SIP), passing from close vicinity of singularities in the complex kp plane. By this, the information content of spectral-domain GFs is preserved, which makes it possible to compute the far-fields accurately. Thus, the method can be applied to the analysis of electrically large structures near layered media. The proposed method is direct with only one approximation level. [ABSTRACT FROM AUTHOR]