A Mathematical Analysis of the Electromagnetic Compatibility of Twisted Wires

In this paper the electromagnetic compatibility of twisted wires is evaluated. A twisted pair is uniquely represented by arrays of loops and dipoles. For many practical applications, the circum­ ference of the loop is small compared to the wavelength of in ter­ ference. When such is the case, only the transmission mode of pro­ pagation and normal mode of radiation are of interest, as the ax­ ial mode of radiation is very small compared to the normal mode of radiation. Mathematical formulas of power received by arrays for both uniform and non-uniform excitation are compared with the power received by a two-wire line of the same length as the a r­ ray. The relative shielding effectiveness of a twisted-pair cable with respect to a two-wire line is calculated from their power ratio.