Radiation from Microstrip Discontinuities

Radically different methods of calculation by Lewin and by van der Pauw are compared. It is shown that the difference in the two sets of results is due not to the difference in method, but to assumptions on the value of dielectric constant to be used when calculating the substrate polarization. Curves show that differences of up to 30 percent can arise from this source, but the differences are much smaller for the larger values of dielectric constant.