A Logic Module Using Transferred-Electron Logic Devices for Precision Time Interval Measurements.
Abstract
The results of a program to develop a logic module using transferred electron logic devices (TELDs) for use in a short baseline time-difference-of-arrival (TDOA) direction finding system are described. The function of the logic module is to perform high precision, single-event time interval measurements. The ultimate goal for precision is 20 ps. The purpose of the present program is to prove feasibility of time measurement with subnanosecond resolution in a breadboard TELD module. The two input threshold gates and the coincidence circuit utilize TELDs and the pulse burst generators are constructed with GaAs MESFETs. Step recovery diodes have been used for pulse shaping at several points in the circuit. The counters are commercially available and of ECL type. A thorough study was made of the circuit design of the module's components and the results are contained herein. A breadboard system was designed, constructed, and tested without the ECL counters. Four pulses were used for each pulse burst generator and Tc approx 1.2 ns. This produced a resolution of about 400 ps which was confirmed in the tests. In these tests the output of the coincidence circuit was observed as the time delay of the rf signal (0.8 GHz) to one channel was varied. The range of measurement (with counters) is about 2 ns, which is adequate for the present application.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1977
- Accession Number
- ADA045819
Entities
People
- W. R. Curtice
Organizations
- RCA Corporation