Controllable AC voltage amplifier

摘要

A broadband amplifier having controllable amplification and an extremely high upper frequency limit includes a single-gate field-effect transistor arranged in a common-source configuration and a variable voltage source connected to the source terminal of the single-gate field-effect transistor. The gate terminal of the single-gate field-effect transistor is connected to RF input signals to be amplified. The drain current ID is varied by a controllable voltage; this voltage changes the gain but does not change the low resistance during the controlled process. The transconductance S of the single-gate field-effect transistor is portional to the square root of the drain current ID. Thus, two or more single-gate field-effect transistors can be connected in series to form a multiple-stage amplifier without interfering with one another.