Neets Master Glossary

1-20 DOPING—The process of adding impurities to semiconductor crystals to increase the number of free charges that can be moved by an external, applied voltage. Doping produces N-type or P-type material [7] [14]. DOPPLER EFFECT—(1) The apparent change in frequency or pitch when a sound source moves either toward or away from a listener [10]. (2) In radar, the change in frequency of a received signal caused by the relative motion between the radar and the target [18]. DOPPLER FREQUENCY—The difference between transmitted and reflected frequencies; caused by the Doppler effect [18]. DOUBLE-MODING—In a transmitter output tube, the abrupt and random change from one frequency to another [18]. DOUBLE NEGATIVE LAW—In Boolean algebra, the law which states that the complement of a complement is the equivalent of the original term [13]. DOUBLE RECEIVER—A fine and coarse synchro receiver enclosed in a common housing with a two- shaft output (one shaft inside the other) [15]. DOUBLET—Another name for the dipole antenna [10]. DOUBLING UP—This is a type of two-equipment installation where one unit can be substituted for another in the event of failure [17]. DOWN LINK—The frequency used to transmit an amplified signal from a satellite or other craft back to earth [17]. DRIFT SPACE—In an electron, a region free of external fields in which relative electron position depends on velocity [11]. DRIVEN ARRAY—An array in which all of the elements are driven [10]. DRIVEN ELEMENT—The element of an antenna connected directly to the transmission line [10]. DRIVER—The final stage of amplification [8]. DRUM-TYPE ARMATURE—An efficient, popular type of armature designed so that the entire length of the winding is cutting the field at all times. Most wound armatures are of this type [5]. DRY-AIR SYSTEM—Provides dehumidified air for electronic equipment that is moisture critical [18]. DRY CELL—An electrical cell in which the electrolyte is not a liquid. In most dry cells the electrolyte is in the form of a paste [1]. DUAL-GATE MOSFET—A two-gate MOSFET in which either gate can control the conductor independently, a fact which makes this MOSFET very versatile [7]. DUAL IN-LINE PACKAGE (DIP)—IC package having two parallel rows of preformed leads [14]. DUCTILE—Easily drawn out (as to form filaments or wires) [4]. DUCTING—Trapping of an RF wave between two layers of the earth's atmosphere or between an atmospheric layer and the earth [18].