AI-2
FIDELITY—The quality of reproducing an output signal exactly like the input signal except for
amplitude (and somtimes phase); i.e., output and input signals exactly alike in terms of frequency
and shape.
FREQUENCY-DETERMINING NETWORK—A circuit that provides the desired response
(maximum or minimum impedance) at a specific frequency.
FREQUENCY-RESPONSE CURVE—A curve showing the output of an amplifier (or any other
device) in terms of voltage or current plotted against frequency with a fixed-amplitude input signal.
GAIN-BANDWIDTH PRODUCT—The number that results when the gain of a circuit is multiplied by
the bandwidth of that circuit. For an operational amplifier, the gain-bandwidth product for one
configuration will always equal the gain-bandwidth product for any other configuration of the same
amplifier.
HALF-POWER POINTS—The points on a frequency-response curve at which the output power is one-
half of the maximum power out.
HIGH-FREQUENCY COMPENSATION—See peaking coil.
KNEE OF THE CURVE—The point of maximum curvature. (Shaped like the knee of a leg that is bent.)
MAGNETIC AMPLIFIER (MAG AMP)—An amplifier that uses electromagnetic effects to provide
amplification of a signal. The magnetic amplifier uses a changing inductance to control the power
delivered to a load.
NEGATIVE FEEDBACK—Feedback in which the feedback signal is out of phase with the input signal.
Also called DEGENERATIVE FEEDBACK.
NEUTRALIZATION—The process of counteracting or "neutralizing" the effects of interelectrode
capacitance.
OPERATIONAL AMPLIFIER (OP AMP)—An amplifier designed to perform computing or transfer
operations and which has the following characteristics: (1) very high gain, (2) very high input
impedance, and (3) very low out put impedance.
PEAKING COIL—An inductor used in an amplifier to provide high-frequency compensation which
extends the high-frequency response of the amplifier.
PERMEABILITY—The measure of the ability of a material to act as a path for additional magnetic lines
of force.
PHASE SPLITTER—A device that provides two output signals from a single input signal. The two
output signals will differ from each other in phase.
POSITIVE FEEDBACK—Feedback in which the feedback signal is in phase with the input signal. Also
called REGENERATIVE FEEDBACK.
POWER AMPLIFIER—An amplifier in which the output-signal power is greater than the input-signal
power.
PUSH-PULL AMPLIFIER—An amplifler which uses two transistors (or electron tubes) whose output
signals are combined to provide a larger gain (usually a power gain) than a single transistor (or
electron tube) can provide.
