| 摘要 |
PURPOSE:To obtain the effect similar to that when a transistor amplifier is designed by using a large-signal S parameter, by designing it on the basis of a measured small-signal S parameter, a function of a frequency when a transistor is in an unsaturated state. CONSTITUTION:A high-frequency amplifier of FET is designed by calculating characteristics from input reflection coefficient S11 as a function of a frequency, output reflection coefficient S22, input-output transfer coefficient S21, an S parameter of inverse transfer coefficient S12, and the matcher parameter of the amplifier. At this time, an operating bias point selected near point B in an unsaturated state of static characteristics expressed by drain-source voltage VDS and drain-source current IDS to measure the small-signal S parameter for designing. As a result, a high-frequency and high-output amplifier can be designed easily and accurately only by measuring the small-signal S parameter without measuring the complex large-signal S parameter. |
