Method of generating transistor ac scattering parameters simultaneously with dc characteristics using a single circuit simulation with a self-correction scheme for the artificial dc voltage dropped across the 50-ohm resistor representing transmission line impedance
AssigneeTexas Instruments Incorporated
InventorsPaul Ehnis, Keith R. Green
Life of this patent
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Abstract
A method of generating transistor scattering parameters employs a single circuit simulation with a self-correction scheme for the artificial DC voltage dropped across the 50-Ohm resistor representing transmission line impedance. A sub-circuit without 50-Ohm transmission line resistance is used to compute transistor bias current via a current-controlled voltage source to compensate for the DC voltage dropped across a 50-Ohm resistor contained in the network.
Claims6
A method of generating transistor scattering parameters comprising the steps of:
- simulating a circuit for the generation of transistor scattering parameters, wherein the circuit comprises a transistor driving a 50-Ohm transmission line impedance having one portion defined by a 1-Ohm impedance;
- and
- transforming the 1-Ohm impedance into a resistor such that the current through the resistor when driven by either a one-volt DC supply or a one-volt AC supply voltage is equal to the current passing through the transistor.
A method of generating transistor scattering parameters comprising the steps of:
- simulating a circuit for the generation of transistor scattering parameters solely using AC simulation, wherein the circuit comprises a transistor driving a 50-Ohm transmission line impedance having one portion defined by a 1-Ohm impedance;
- transforming the 1-Ohm impedance into a resistor such that the current through the resistor when driven by either a one-volt DC supply or a one-volt AC supply voltage is equal to the current passing through the transistor;
- and
- activating the circuit and selectively measuring the voltage across the resistor or the current through the resistor to extract a scattering parameter associated with the transistor.
Dependencies are inferred from the claim text.