TDR Discontinuity Study Using Gaussian Modulated Ultra Short Pulse in UWB Microwave/mm-Wave Circuits

The time-domain reflectometry technique can characterize both the position and the nature of any discontinuity in the circuits, but as far as complex circuits are concerned, the technique faces limitations. In this letter, separation, position extraction, and nature of multiple close discontinuities in ultra wide-band (UWB) Microwave/mm-wave circuits are investigated and improved using a new technique based on Gaussian modulated ultra short pulse and a useful new algorithm. It is shown that this technique can improve the discontinuities separation, by at least 70%. Also, through the simulation and measurement results of a designed complex UWB power divider and analyzing the reflected signal, ability to this technique (by using a new algorithm) in discontinuity analysis, extraction of reflection positions and separation of discontinuities, with an error less than 4%, is verified. Furthermore, designers can analyze the reflection coefficient from individual discontinuities and reflections in complex Microwave/mm-wave circuits to improve the total circuits' results.

I. Introduction

Over the last decade, many methods, such as time-domain reflectometry (TDR), frequency-domain reflec-tometry (FDR), and time-FDR. for fault location and nature, and transmission line characterization have been developed. Generally, they use different incident signals and different methods and algorithms. Most of these techniques can locate serious faults (open and short circuits) that produce big reflection with a limited degree of precision, and all of them can characterize and separate limited far mismatches and discontinuities, depending on their incident signal bandwidth [1]–[5].