Inverse Transmission Parameters

The transmission parameter and the inverse transmission parameter are duals of each other.

If, instead of quantities ${V_1}$ and ${I_1}$, quantities ${V_2}$ and ${I_2}$ are expressed in terms of ${V_1}$ and ${I_1}$, the resulting parameter $(A',B',C',D')$ are called inverse transmission parameter.

The inverse transmission parameters of the two port network in figure having direction of voltages and current as shown,are given by

${V_2} = A'{V_1} + B'( - {I_1})$

${I_2} = C'{V_1} + D'( - {I_1})$

in matrix form,

$$\left[ \begin{array}{l} {V_2}\\ {I_2} \end{array} \right] = \left( {\begin{array}{*{20}{c}} {A'}&{B'}\\ {C'}&{D'} \end{array}} \right)\left[ \begin{array}{l} {V_1}\\  - {I_1} \end{array} \right]$$

The inverse transmission parameters can be defined as

$A' = \frac{{{V_2}}}{{{V_1}}};{I_1} = 0$ forward voltage ratio with sending end open circuited.

$C' = \frac{{{I_2}}}{{{V_1}}};{I_1} = 0$ transfer admittance with sending end open circuited.

$B' = \frac{{{V_2}}}{{ - {I_1}}};{V_1} = 0$ transfer impedance with sending end short circuited.

$D' = \frac{{{I_2}}}{{ - {I_1}}};{V_1} = 0$ forward current ratio with sending end short circuited.