Frequency dependence of pulse distortions along an exponential microstrip taper

Abstract

The propagation distortions have been numerically calculated for various signals based on a nonideal square pulse along an exponential microstrip taper. Numerical calculations have been performed for propagation distortions of various signals obtained by forcing the cutoff of the frequency components to be higher than some cutoff frequency in the spectrum of the nonideal square pulse. The mechanism in the pulse distortions has been clarified. The large and sharp spikes in the distorted pulse shape are caused by the delay time owing to the phase velocity in the high-frequency region, which is related to the slope part in the curve of the propagation time τL(ω)/2. These magnitudes depend on the magnitudes of spectra of the signal in that frequency region. The plateau distortions in the center and tail parts of the distorted pulse shape are mainly caused by multiple reflections in the low-frequency region below the angular frequency at the first zero point of the reflection coefficient, and occur in the terms of τL(0)/2−μ≤t≤3τL(0)/2+μ. The influence of the length of the taper on the distorted shape has been clarified. © 1999 Scripta Technica, Electr Eng Jpn, 129(4): 7–16, 1999.