A 50 Hz-250 MHz Computer-Operated Transmission Measuring Set

The development of communication systems for the Bell System has, in the past, required large numbers of transmission measurements. These measurements have been costly and time-consuming. With the trend toward more complex systems, the volume and accuracy of measurements must be increased. At the same time, the increased use of computers in modeling and design requires flexibility in the 1339 1340 THE BELL SYSTEM TECHNICAL JOURNAL, M A Y - J U N E 1969 types of data obtained. For example, two-port characterization of devices such as transistors is becoming particularly important. This paper describes a computer-operated transmission measuring set developed for laboratory use in the 50 Hz to 250 M H z frequency range (see Fig. 1). Compared with previously available sets, this set provides increased speed, operating range, accuracy, flexibility, and convenience, and the capacity for types and quantities of measurements previously not practical. The computer-operated measuring set is a part of the centralized measuring facilities being developed for Bell Laboratories. With the addition of various appliques now being developed, the measurement centers will provide additional measurement facilities in the 50 Hz to 250 M H z range, with environmental control, and in the three microwave radio bands at 4, 6, and 11 GHz. The set is also being used for production testing by the Western Electric Company.