Design rules for microstrip capacitance

A variety of published models relating the geometry and material properties to capacitance for microstrip geometry are reviewed. A combination of H.A. Wheeler´s (1977) and M.V. Schneider´s (1969) models is found to agree with previously published data as well as new data presented here to better than 3%. The combination is presented in a form suitable for use in a spreadsheet. In addition to being useful for computer simulation of specific designs, the composite model can yield some useful insight to add to the intuition of fabrication and design engineers