Calculation of crosstalks in multiple-conductor cables
The rigorous method of calculations of characteristics of two-wire lines (twisted pairs) inside the metal armor and of a mutual coupling between lines is considered. It is shown that the mutual coupling between lines in multiple-conductor cables results in appearance of electromagnetic interferences (crosstalks) in communication channels. The voltages values (interferences) across the impedances placed at the beginning and the end of the adjacent line at the given power in the main line are determined.
Analysis of the helical twisted-wire pair running above ground: transfer function evaluation
This paper deals with the analysis of an internally excited three-conductor nonuniform transmission-line system comprising a twisted wire pair (TWP) running above a conducting plane. Research is conducted aimed at the analysis and characterization of the propagation properties of a helical-type TWP system with lossy conductors. Numerical simulation results regarding the attenuation and phase-velocity characteristics of this transmission-line system are obtained by using a TWP model consisting of a cascade of small incremental parallel segments subjected to continuous rotation. Special attention is paid to the derivation and analysis of the frequency-domain voltage transfer function describing the behavior of the TWP structure with a number N of twists. Time-domain results concerning the system response to a pulse train excitation are also obtained by making use of the information conveyed by the transfer function. Both frequency- and time-domain simulation results reported here show that the periodicity arising from wire twisting may dramatically modify the transmission-line system propagation properties as compared to those concerning the untwisted case.
On the Response of a Terminated Twisted-Wire Cable Excited by a Plane-Wave Electromagnetic Field
The currents induced in the terminations of a twisted-pair cable are obtained for a plane-wave electromagnetic-field. Various termination configurations are considered and comparisons are made with the corresponding results for untwisted pairs. In special cases, the twisted cable may have a larger induced signal than the untwisted. Under various common restrictions, the induced signal is inversely proportional to either 1) the square of the number of turns or 2) the number of turns.