FET Fundamentals Unit 3 – JFET Amplifier
The ac voltage drop across the bias source resistor (RS) produces a degenerative feedback
(reduced circuit gain).
NEW TERMS AND WORDS
amplifiers - circuits that increase the level of an input signal without distortion.
transconductance - a measure of the amplification capability of a JFET, stated in micromhos.
common source amplifiers - circuits having an input signal applied to the gate and an output
signal taken from the drain (both with respect to circuit common).
degenerative feedback - feedback that reduces circuit gain but increases circuit bandwidth.
source bypass - capacitive bypass of a source resistor.
fixed bias - a JFET that requires a fixed level of dc bias voltage between the gate and source
terminals of the device.
source bias - a JFET bias that requires a resistor in series with the source terminal.
EQUIPMENT REQUIRED
F.A.C.E.T. base unit
FET FUNDAMENTALS circuit board
Multimeter
Oscilloscope, dual trace
Generator, sine wave