1-83 VOLTAGE REGULATION—A measure of the ability of a generator or power supply to maintain a constant output voltage from no-load to full-load operation. Expressed as a percentage of full-load voltage; the better the regulation, the lower the percent [5]. VOLTAGE STANDING WAVE RATIO (VSWR)—In a waveguide, the ratio of the electric field(voltage) at a maximum point to that of an adjacent minimum point [10] [18]. VOLTMETER—A meter used to measure voltage [3] [16]. WAFER—A slice of semiconductor material upon which monolithic ICs are produced [14]. WAFER SWITCH—A rotary switch in which the contacts are arranged on levels. Each level (wafer) is electrically independent but mechanically connected by the shaft of the switch [3]. WATT—The unit of electrical power that is the product of voltage and current [16]. WATTAGE RATING—A rating expressing the maximum power that a device can safely handle [1]. WATT-HOUR—A practical unit of electrical energy equal to one watt of power for one hour [1]. WATT-HOUR METER—A meter used to measure electrical energy [3]. WATTMETER—A meter used to measure electrical power [3] [16]. WAVE ANTENNA—Same as BEVERAGE ANTENNA [10]. WAVEFORM—The shape of the wave obtained when instantaneous values of an ac quantity are plotted against time in rectangular coordinates [2]. WAVEFORM ANALYSIS—Observation displays of voltage and current variations with respect to time or by harmonic analysis of complex signals [16]. WAVEFRONT—A small section of an expanding sphere of electromagnetic radiation that is perpendicular to the direction of travel of the energy [10]. WAVEGUIDE—A rectangular, circular, or elliptical metal pipe designed to transport electromagnetic waves through its interior [10] [11]. WAVEGUIDE DUPLEXER—TR and atr tubes housed in a resonant cavity attached to a waveguide system. WAVEGUIDE MODE OF OPERATION—Any particular field configuration in a waveguide that satisfies the boundary conditions. Usually divided into two broad types: the transverse electric (TE) and the transverse magnetic (TM) modes [11]. WAVEGUIDE POST—A rod of conductive material used as impedance changing devices in waveguides [11]. WAVEGUIDE SCREW—A screw that projects into a waveguide for the purpose of changing the impedance [11]. WAVELENGTH—The distance, usually expressed in meters, traveled by a wave during the time interval of one complete cycle. It is equal to the velocity divided by the frequency [2] [10] [12].