Neets Master Glossary

1-29 FREQUENCY SYNTHESIZER—(1) A frequency source of high accuracy [17]. (2) A bank of oscillators in which the outputs can be mixed in various combinations to produce a wide range of frequencies [18]. FRONT-TO-BACK RATIO—The ratio of the energy radiated in the principal direction compared to the energy radiated in the opposite direction [10]. FULL-WAVE RECTIFIER—A circuit that uses both positive and negative alternations in an alternating current to produce direct current [6] [7]. FULL-WAVE VOLTAGE DOUBLER—Consists of two half-wave voltage rectifiers and is used to reduce the output ripple amplitude [7]. FUNCTION—A specific purpose of an entity; its characteristic action [13]. FUNDAMENTAL FREQUENCY—The basic frequency or first harmonic frequency [10]. FUSED-ALLOY JUNCTION—See ALLOYED-JUNCTION [7]. GAIN—(1) The ratio between the amount of energy propagated from an antenna that is directional compared to the energy from the same antenna that would be propagated if the antenna were not directional [10]. (2) Any increase in the strength of a signal [18]. 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 [8]. GALENA—A crystalline form of lead sulfide used in early radio receivers [7]. GALVANOMETER—A meter used to measure small values of current by electromagnetic or electrodynamic means [3] [4] [16]. GAMMA ( g )—The emitter-to-base current ratio in a common-collector configuration [7]. GANGED TUNING—The process used to tune two or more circuits with a single control [17]. GAS—One of the three states of matter; it has no fixed form or volume [1]. GATE—As applied to logic circuitry, one of several different types of electronic devices that will provide a particular output when specified input conditions are satisfied. Also, a circuit in which a signal switches another signal on or off [13]. GATED AGC—Circuit that permits automatic gain control to function only during short time intervals [18]. GATED-BEAM DETECTOR—An FM demodulator that uses a special gated-beam tube to limit, detect, and amplify the received FM signal. Also known as a quadrature detector [12]. GATING—The process of selecting those portions of a wave that exist during one or more selected time intervals or that have magnitudes between selected limits. Also, the application of a specific waveform to perform electronic switching [13].