An Oversampling Delta-Modulator for Digitizing Amplitude of Ultra-Short Pulses Based on High Temperature Superconductor

40585 November 12, 1996 Conductus, Inc. Accurate energy measurement of ultra-high-rate particles in nuclear physics experiments depends on high performance detectors and electronic systems. This project will develop a modulator, based on high temperature superconducting (HTS) technology, that will enable the readout of high-rate particles with very high resolution. It has the advantages of high speed, low power dissipation, and operation up to the liquid nitrogen temperature range. This circuit is very low complexity (about 10 junctions) with very high resolution. Simulations show that this device offers a current resolution of 5 ¿A, for a pulse width of 400 ps. It is also the basis for an over sampling analog-to-digital converter (ADC) which has many applications in nuclear physics instrumentation and data processing. Phase I will design, fabricate, and test the over sampling delta-modulator which can be used directly for digitizing pulse amplitude. Phase II, will implement this modulator for DOE, and develop a complete HTS ADC which will include this over sampling modulator, a feed back loop, and digital filter system. Anticipated Results/Potential Commercial Applications as described by the awardee: Due to the high sampling rate, on the order of 100 GHz, the counter could be used in the front ends of most digital systems, in time interpolation, and in many measurement applications such as for navigation or range finding systems with high accuracy.