Computer-Aided Analysis and Design of Negative Impedance Boosted Transmission Lines

Negative impedance boosting using active circuits series connected at intervals along a cable pair has been shown to minimize loss and provide nearly distortionless bilateral transmission of either digital or analog signals. Results from computation and field measurements are in good agreement. Recently, on-line plotting with a time-shared computer has made it feasible to find the circuit parameters which minimize the remaining distortion for many commonly used cables and spacings. Parameter adjustments are shown which permit a tradeoff between bandwidth and either amplitude or phase distortion. Factors affecting pulse transmission have been investigated. In general, bandwidth is inversely related to booster spacing. Bandwidth-spacing relations are given for two cable gauges and compared with the upper bound where propagation is at light velocity. Bandwidth increases with wire size, while the bandwidthspacing product improves with reduced spacing.