. The Bell System technical journal . two polynomials in fre-quency. A network to be one of a constant resistance pair musthave certain restrictions imposed on its admittance. In case thetwo networks are both filters of negligible dissipation, the expres-sion for the input conductance of each may be written from aknowledge of the required loss characteristic. The poles of the expression for the conductance are then will be identical for the two networks. The networks arethen built up by synthesis from those poles of the conductancewhich have negative real parts, these corresponding
. The Bell System technical journal . two polynomials in fre-quency. A network to be one of a constant resistance pair musthave certain restrictions imposed on its admittance. In case thetwo networks are both filters of negligible dissipation, the expres-sion for the input conductance of each may be written from aknowledge of the required loss characteristic. The poles of the expression for the conductance are then will be identical for the two networks. The networks arethen built up by synthesis from those poles of the conductancewhich have negative real parts, these corresponding to real networkelements. The methods which have been developed for this last processare described in detail. ONE of the most useful principles available to the network designengineer is that of constant resistance networks. The use ofthese networks is widespread in the telephone system for purposes ofloss equalization and distortion correction, where they have theadvantage of providing a means for altering the transmission properties. •Z2 LATTICE SHUNT SERIES Fig. 1—The three fundamental forms of constant resistance networks. of a circuit without affecting its impedance. The three usual typesof constant resistance networks are shown in Fig. 1, where, in allcases, Z1Z2 = R^, a relationship which is always possible to fulfill if 1 Distortion Correction in Electrical Circuits with Constant Resistance RecurrentNetworks, Otto J. Zobel, Bell Sys. Tech. Jour., July 1928. 178 CONSTANT RESISTANCE NETWORKS 179 Zi and Z2 are built up of resistive and reactive elements in the usualway. The lattice type will not be considered here. The first step inextending the other two is shown in Fig. 2, where the networks shown
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
