Negative impedance boosting

Linearized and feedback-stabilized negative impedance circuits having only R, C, and solid state components, powered in series at intervals along a cable pair, offer new possibilities in bilateral transmission. After discussing the basic negative impedance boosting units and the transmission characteristics they impart to a line (computed, with experimental confirmation), this paper describes a field test of two 32-mile telephone lines, largely 22-gauge, each having an insertion loss of only 3 dB at 1,000 Hz. It also shows means for broadening bandwidth and almost eliminating delay distortion over negative impedance boosted lines. Treatment of this sort adapts them to unusual uses. Examples include converting rectangular to raised-cosine pulses in transmission, without pulse-forming circuitry, and the bilateral two-wire transmission of carrier or pulse signals in both directions simultaneously, without frequency separation.