Enhanced Tunable Ultra-Wideband Pulse Generation Based on Variable Edge-Rate Compression

The most recurrent pulse generator design approach described in literature employs a series step recovery diode (SRD) and pulse-duration tuning subsequent to Gaussian pulse formation. Although this conventional approach is advantageous in fixed pulse-duration designs, it leads to relatively complex designs for tunable generators. This paper presents a variable edge-rate compression (VERC) approach, to tunable ultra-wideband (UWB) generator design, that entails tuning prior to Gaussian pulse formation and a shunt configuration of forward and reverse biased SRDs. Compared to the conventional approach, VERC offers performance advantages that include broader tuning range, improved tuning sensitivity, increased design simplicity and reduced cost. A comparison of the series and shunt SRD configurations reveals that input-signal slew rate has a dominant effect on pulse-duration tuning for an SRD in a shunt configuration. As slew rate may be modified using frequency, rise time or voltage, the VERC approach also offers greater design flexibility and is more advantageous for tunable UWB generator design