Neets Master Glossary

1-52 PARASITIC ARRAY—An antenna array containing one or more elements not connected to the transmission line [10] [18]. PARASITIC ELEMENT—The passive element of an antenna array that is connected to neither the transmission line nor the driven element [10]. PART—A part is one component or two or more components joined together. It is not normally subject to disassembly without destruction [17]. PASSIVE SATELLITE—A satellite that reflects radio signals back to earth [17]. PATCH PANEL—A panel used to tie a receiver or transmitter to its associated equipment [17]. PEAK AMPLITUDE—The maximum value above or below the reference line [12]. PEAK CURRENT—The maximum current that flows during a complete cycle [6]. PEAK DETECTION—Detection that uses the amplitude of pam or the duration of pdm to charge a holding capacitor and restore the original waveform [12]. PEAKING COIL—An inductor used in an amplifier to provide high-frequency compensation, which extends the high-frequency response of the amplifier [8]. PEAK POWER—The maximum value of the transmitted pulse [12]. PEAK-REVERSE VOLTAGE—The peak ac voltage that a rectifier tube will withstand in the reverse direction [6]. PEAK-TO-PEAK—The measure of absolute magnitude of an ac waveform, measured from the greatest positive alternation to the greatest negative alternation [2]. PEAK VALUE—The maximum instantaneous value of a varying current, voltage, or power. It is equal to 1.414 times the effective value of a sine wave [2]. PEAK VOLTAGE—The maximum value present in a varying or alternating voltage. This value may be positive or negative [6]. PENTAVALENT IMPURITY—A type of impurity that contains five valence electrons and donates one electron to the doped material. Also called DONOR IMPURITY [7]. PENTODE TUBE—A five-electrode electron tube containing a plate, a cathode, a control grid, and two grids [6]. PERCENT OF MODULATION—The degree of modulation defined in terms of the maximum permissible amount of modulation [12]. PERFORATOR—A device that stores a teletypewriter message on a paper tape [17]. PERIGEE—The point in the orbit of a satellite closest to the earth [17]. PERIOD TIME—The time required to complete one cycle of a waveform [2] [10] [12]. PERIODIC WAVE—A waveform that undergoes a pattern of changes, returns to its original pattern, and then repeats the same pattern of changes. Examples are square waves, rectangular waves, and sawtooth waves [9].