Microstrip line on ground plane with closely spaced perforations-simple CAD formulas by synthetic asymptote

Simple CAD formulas, of a microstrip line on a ground plane with periodic perforations, closely spaced and at low frequency, are derived for possible application in the multi-layer circuits in an LTCC package. The derivation is done by the novel technique of synthetic asymptote. Compared with the hardware experiment, the average error of the CAD formulas can be as low as 2.5%. The formulas have no arbitrary constants and give good physical insights.