二端子対回路
アドミタンス行列、Y行列とも。
( I 1 I 2 ) = ( Y 11 Y 12 Y 21 Y 22 ) ( V 1 V 2 ) {\displaystyle {I_{1} \choose I_{2}}={\begin{pmatrix}Y_{11}&Y_{12}\\Y_{21}&Y_{22}\end{pmatrix}}{V_{1} \choose V_{2}}}
Y 11 {\displaystyle Y_{11}} ・ Y 12 {\displaystyle Y_{12}} ・ Y 21 {\displaystyle Y_{21}} ・ Y 22 {\displaystyle Y_{22}} の各アドミタンスパラメータは以下のとおり。
Y 11 = I 1 V 1 | V 2 = 0 Y 12 = I 1 V 2 | V 1 = 0 {\displaystyle Y_{11}={I_{1} \over V_{1}}{\bigg |}_{V_{2}=0}\qquad Y_{12}={I_{1} \over V_{2}}{\bigg |}_{V_{1}=0}}
Y 21 = I 2 V 1 | V 2 = 0 Y 22 = I 2 V 2 | V 1 = 0 {\displaystyle Y_{21}={I_{2} \over V_{1}}{\bigg |}_{V_{2}=0}\qquad Y_{22}={I_{2} \over V_{2}}{\bigg |}_{V_{1}=0}}