10 Facts About Two-port parameters

Two-port parameters network is an electrical network or device with two pairs of terminals to connect to external circuits.

The term hybrid to describe these parameters was coined by D A Alsberg in 1953 in "Transistor metrology".

In 1954 a joint committee of the IRE and the AIEE adopted the term h Two-port parameters and recommended that these become the standard method of testing and characterising transistors because they were "peculiarly adaptable to the physical characteristics of transistors".

ABCD-Two-port parameters are known variously as chain, cascade, or transmission Two-port parameters.

Previous Two-port parameters are all defined in terms of voltages and currents at ports.

S-Two-port parameters are different, and are defined in terms of incident and reflected waves at ports.

S-Two-port parameters are used primarily at UHF and microwave frequencies where it becomes difficult to measure voltages and currents directly.

The difference is that T-Two-port parameters relate the waves at port 1 to the waves at port 2 whereas S-Two-port parameters relate the reflected waves to the incident waves.

However, S-Two-port parameters are easily converted to T-Two-port parameters, see main article for details.

Two-port parameters network has four variables with two of them being independent.