Two-port elements

• Transformer

definition in the form of the cascade matrix:

• Gyrator

definition in the form of the cascade matrix:

Circuit symbols used for these two-port elements are shown in the following figure:

Immitance

Ratio of the Laplace transform of the across variable to the Laplace transform of the through variable

in the case of harmonic variables can be written as a ratio of respective phasors:

In the "effort-to-voltage" convention, the immitance is equal to the impedance

In the "flow-to-voltage", the immitance is equal to the admittance (often called mobility)