FIDELITYThe 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
FREQUENCY-DETERMINING NETWORKA circuit that provides the desired response
(maximum or minimum impedance) at a specific frequency.
FREQUENCY-RESPONSE CURVEA 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 PRODUCTThe 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
HALF-POWER POINTSThe points on a frequency-response curve at which the output power is one-
half of the maximum power out.
HIGH-FREQUENCY COMPENSATIONSee peaking coil.
KNEE OF THE CURVEThe 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 FEEDBACKFeedback in which the feedback signal is out of phase with the input signal.
Also called DEGENERATIVE FEEDBACK.
NEUTRALIZATIONThe process of counteracting or "neutralizing" the effects of interelectrode
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 COILAn inductor used in an amplifier to provide high-frequency compensation which
extends the high-frequency response of the amplifier.
PERMEABILITYThe measure of the ability of a material to act as a path for additional magnetic lines
PHASE SPLITTERA device that provides two output signals from a single input signal. The two
output signals will differ from each other in phase.
POSITIVE FEEDBACKFeedback in which the feedback signal is in phase with the input signal. Also
called REGENERATIVE FEEDBACK.
POWER AMPLIFIERAn amplifier in which the output-signal power is greater than the input-signal
PUSH-PULL AMPLIFIERAn 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.