Two wire coupling

Starting from a circuit (lumped) model, valid in the low frequency limit, and extending this to higher frequencies, the exact description of a two wire coupling in terms of its admittance matrix is obtained. The voltages at the ends of the victim wires are obtained as transfer functions of the voltage at the source end of the culprit wire. These transfer functions are studied with various load resistor values, and plots are provided. Approximate formulas to express the transfer functions are obtained. These formulas have an extended range of validity with respect to the well known one obtained from capactive and inductive coupling models.