Electrical Engineering ⇒ Topic : Conductively coupled and mutual impedance

CONDUCTIVELY COUPLED CIRCUIT AND MUTUAL IMPEDANCE

A conductively coupled circuit which does not involve magnetic coupling is shown in Fig. (a).

In the circuit shown the impedance Z₁₂ or Z₂₁ common to loop 1 and loop 2 is called mutual impedance. It may consists of a pure resistance, a pure inductance, a pure capacitance or a combination of any of these elements. Mesh analysis, nodal analysis or Kirchhoff's laws can be used to solve these type of circuits as described in Chapter 2.The general definition of mutual impedance is explained with the help of Fig.(b).

                                   Fig. (a)                                                                                       Fig. (b)

The network in the box may be of any configuration of circuit elements with two ports having two pairs of terminals 1-1 and 2-2 available for measurement.The mutual impedance between port 1 and 2 can be measured at 1-1 or 2-2 . If it is measured at 2-2. It can be defined as the voltage developed (V₂) at 2-2 per unit current (I₁) at port 1-1 . If the box contains linear bilateral elements, then the mutual impedance measured at 2-2 is same as the impedance measured at 1-1 and is defmed as the voltage developed (V₁) at 1-1 per unit current (/₂) at port 2-2 .