Simple CAD formulas of edge-compensated microstrip lines

The proximity effects of microstrip lines near a substrate edge are estimated by using the rectangular boundary division method for effectively designing high-packing-density MMICs (monolithic microwave integrated circuits). Simple CAD (computer-aided design) formulas of edge-compensated microstrip lines (ECM lines) are introduced which can be applied to circumvent the proximity effects on the characteristic impedance. The practical design parameters of the ECM lines are given in the form of numerical data and simple polynomials for CAD work with a curve-fitting procedure. Results of capacitance measurements are compared with this theory.<>