Dispersion characteristics of transient signals in microstrip step discontinuity

An analysis is presented of the transmission of an electromagnetic pulse through a step discontinuity between two microstrip lines of different width. The step discontinuity is first characterized by a two-port network for which the frequency dependence of the scattering parameters is determined by the method of lines. Using the Fourier transform technique, transient responses of the step discontinuity to various pulses are then investigated for different ratios of strip widths and substrate materials. It is found that the distortion of pulses propagating through the step discontinuity can be substantial, particularly for the case of large width ratio and substrate of high dielectric constant.<>