Variables are user defined circuit attributes that allow the analysis engine, em, to modify the circuit in order to perform parameter sweeps and optimization. Variables also provide a quick way for the user to change dimensions in the project editor or multiple elements in a circuit. For example, the length of a transmission line can be assigned the variable “L.” To change the length of the transmission line, you edit the value for “L.” Another example would be a circuit which contains 10 resistors, all of which have the same value. Entering a variable “R” for the resistance of these ideal components allows you to change the value of all 10 resistors by changing the value in only one place.
Note: Just because it is possible to use a variable in any given property field, does NOT make it necessary to do so. You may enter a nominal value for the field instead of a variable if you do not wish to change that particular property during analysis.
A variable’s value may be defined using:
Any of these definitions may be directly entered into a property field. For a more detailed discussion of equations, please see Equations.