TURNSTILE ANTENNAA type of antenna used in vhf communications that is omnidirectional and
consists of two horizontal half-wave antennas mounted at right angles to each other in the same
TWISTED PAIRA line consisting of two insulated wires twisted together to form a flexible line
without the use of spacers.
TWO-WIRE OPEN LINEA parallel line consisting of two wires that are generally spaced from 2 to 6
inches apart by insulating spacers.
TWO-WIRE RIBBON (TWIN LEAD)A parallel line similar to a two-wire open line except that
uniform spacing is assured by embedding the two wires in a low-loss dielectric.
ULTRASONICSounds above 20,000 hertz.
UNIDIRECTIONAL ARRAYAn array that radiates in only one general direction.
UNTUNED LINEAnother name for the flat or nonresonant line.
V ANTENNAA bi-directional antenna, shaped like a V, which is widely used for communications.
VELOCITYThe rate at which a disturbance travels through a medium.
VERTICAL AXISOn a graph, the straight line axis oriented from bottom to top.
VERTICAL PATTERNThe part of a radiation pattern that is radiated in the vertical plane.
VERTICALLY POLARIZEDWaves radiated with the E field component perpendicular to the earth's
VOLTAGE-FEED METHODSame as END FEED METHOD.
VOLTAGE STANDING-WAVE RATIO (VSWR)The ratio of maximum to minimum voltage of a
WAVE ANTENNASame as BEVERAGE ANTENNA.
WAVE MOTIONA recurring disturbance advancing through space with or without the use of a
WAVE TRAINA continuous series of waves with the same amplitude and wavelength.
WAVEFRONTA small section of an expanding sphere of electromagnetic radiation, perpendicular to
the direction of travel of the energy.
WAVEGUIDEA hollow metal tube used as a transmission line to guide energy from one point to
WAVELENGTH(1) The distance in space occupied by 1 cycle of a radio wave at any given instant.
(2) The distance a disturbance travels during one period of vibration.
YAGI ANTENNAA multielement parasitic array. Elements lie in the same plane as those of the end-