Question

For an ABCD parameter of a transmission line, which of the following is correct?
1. AB – CD = 1
2. BD – AC = 1
3. AD – BC = 1
4. AD – BC = 0

Answer 1

Correct Answer - Option 3 : AD – BC = 1

ABCD Parameter:

We know that the ABCD parameter of the transmission line

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

A = D

AD – BC = 1

Conditions of reciprocity and symmetry in terms of different two-port parameters are:

Parameter	Conditions of reciprocity	Conditions of symmetry
Z	z12 = z21	z11 = z22
Y	y12 = y21	y11 = y22
T(ABCD)	(AD – BC) = 1	A = D
h	h12 = -h21	(h11h22 – h12h21) = 1