• If one set of parameters is known, other parameters can be found using simple conversions. This can help when one set of parameters is needed, but cannot be measured directly.


• Simple cases of networks are reciprocal and symetrical. When a network is neither of these, then it typically has active components, dependant sources, etc.


1.2.1 Reciprocal Networks


• If a voltage is applied at one port, the short circuit current out the other port will be the same, regardless of which side the voltage is applied to.


• Reciprocal networks are only possible when passive elements are used.


• The parameters that indicate a reciprocal networks are,



• With any reciprocal network we only need to find 3 of the four parameters, the last can be determined mathematically.



1.2.2 Symmetrical Networks


• This is a special case of the reciprocal network where the input and output parameters are identical.


• In addition to the reciprocal constraints, we must also consider,



• Only two of these parameters need to be found to find the other two parameters.