Edge-triggered driver circuit for ultra-wideband pulse generator with cascode impulse shaping

摘要

An ultra-wideband (UWB) pulse generator circuit is said to be the heart of any UWB system. However, the pulse generator typically requires an edge-triggered driver that is the essential signal source of any pulse generator. The design of edge-triggered driver circuit influences the amplitude, the pulse repetition, and the width of UWB pulses at the output. In this study, a low cost and low complexity edge-triggered driver circuit is proposed, which creates a square wave with very short rising and falling edges to feed a step recovery diode based pulse generator with cascode pulse shaping circuit. The proposed driver circuit is tuneable by simply changing the crystal oscillator component in the circuit, which results in different pulse repetition frequency for the UWB pulse generator. The measurement results when changing the crystal oscillator from 1MHz to 8MHz showed that the output UWB pulse was a Gaussian pulse with pulse width of 1.87 ns and pulse amplitude of 2.16 Vp.