This page is designed to convert between different 2 port specification and can also do some calculation on a 2 port circuit. It is possible to select between letters and number syntax and select with and without complex values.
Parameters can be specied in any of these formats (with a few exceptions) and express exactly the same behavior.
It is also possible to select a circuit and have it converted to a two port representation and draw a curve of some circuit parameters dependency on frequence.

Two ports supported

Impedance (Z)
Admittance (Y)
Hybrid (H) often used for LF transistors
Inverse hybrid (G) gf for a mos transistor
Transmission (A) (ABCD) (T)
Inverse transmission (B) (S)

Input values

The input values will depend on the selected sensor type.

Model type	Select model displayet and used for output result
Input model	Model used for input parameters
Z/Y/H/G/A/B	First used to designate model in parameters
i or 11	Input parameter
r or 12	Reverse parameter, how signal on output affects input
f or 21	Forward parameter, how signal on input affects output (i.e. Hfe is hybrid model, forward(gain) in commen emitter circuit)
o or 22	Output parameter
i or P	imaginary part or Phase angle of value
Source Z	Impedance of source circuit
Load Z	Impedance of load circuit
Input U	Voltage from source circuit
Curve	Opens the "Curve plotter page" and show the frequence response of the defined circuit. This selection will only be available when a circuit is selected, Source Z and Load Z are real values
Letters	When checked the i/r/f/o indices are used, else 11/12/21/22 indices are used
Complex	When checked all input can be complex numbers. Output will display complex values when required.
Phase input	When checked specify all input values as phase angle
Phase output	When checked all complex output is shown as phase angle

Output values

Formulas	Formulas are show for both input and output models
Z/Y/H/G/A/B	The parameters from the input model converted to the output model Source/load values are ignored
Zin	Input impedance of model when output is unloaded
Zout	Output impedance of model when input unconnected
Gain	Voltage/current gain when output unloaded/shorted
Revers	Voltage/current revers (output to input) gain when input unloaded/shorted)

With specified source and load (Requires selection of "Use")

Zi	Input impedance of model when using specifed Zout
Zout	Output impedance of model when using specified Zin
Av	Voltage gain of model when using specified Zout, based on voltage at input terminals
Ai	Curret gain of model when using specified Zout, based on current into input terminals
Vi	Voltage at input terminal when supplying "Input U" from specified "Source Z" and output is loaded with "Load Z"
Ii	Current into input terminal when supplying "Input U" from specified "Source Z" and output is loaded with "Load Z"
Vo	Voltage at output terminal when supplying "Input U" from specified "Source Z" and output is loaded with "Load Z"
Io	Current into output terminal when supplying "Input U" from specified "Source Z" and output is loaded with "Load Z"

Alternate parameter names
Only used for "Transmission" and "Inverse transmission" model, because parameters are some times called ABCD/EFGH and not the usual names.

Circuits

When using circuits the displayed two-port parameters are calculated at the specified frequence, but the curves are made from a frequence sweep.

Hints

Parameters with the value 0 can not be converted between all models, i.e. 0 ohm is very difficult to express as conductance
Some other conditions can also prevent conversion between some models
Many calculations are done with formulas appropriate to the selected models, this avoids problems with impossible model conversions
To break a connection in a T or PI circuit, use a very large resistor

Other pages

1 order filter can design filters
Serial/parallel can be used to make non-standard component values