I came across an exercise that asks you to find the \$Y\$ matrix of a two-port network. It's not a difficult question, and there are two methods that I can see to solve it.
The first method is to use the definition of Y parameters.
The second method is to write KCL for the middle node \$V\$, solve for V as a function of \$V_1\$ and \$V_2\$, and then find \$I_1\$ and \$I_2\$ as a function of \$V_1\$ and \$V_2\$. From there, we can extract \$Y_{11}\$, \$Y_{12}\$, \$Y_{21}\$, and \$Y_{22}\$.
However, assuming that you have the admittance matrix of the 3x3 circuit (which can also be obtained easily by inspection), is there a simple way to convert the 3x3 matrix to the admittance matrix of the two-port network so that we can directly extract \$Y_{11}\$, \$Y_{12}\$, \$Y_{21}\$, and \$Y_{22}\$.
Y = \$ \begin{pmatrix} Y_{1} & -Y_{1} & 0 \\ -Y_{1} & Y_{1}+Y_{2}+Y_{3} & -Y_{3} \\ 0 & -Y_{3} & Y_{3}+Y_{4}\\ \end{pmatrix} \$
I'm not a student, I'm just curious if there exists a method like that.
