"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M",
"N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"

UNBALANCED LINE. A transmission line, such as a coaxial cable, in which the magnitudes of the voltages on the two conductors are not equal with respect to ground.



UNIFORM TRANSMISSION LINE. A transmission line that has distributed electrical properties, i.e., resistance, inductance, and capacitance per unit length, that are constant along the line, and in which the voltage-tocurrent ratio does not vary with distance along the line, if the line is terminated in its characteristic impedance.

UNIPOLAR SIGNAL. A two-state signal where one of the states is represented by voltage or current and the other state is represented by no voltage or current.

USB. Universal Serial Bus, a computer bus which provides two-way communication between the PC and peripheral devices, over a differential 4-wire serial interface cable. [Universal Serial Bus]

Utopia Bus. A Bus Standard used as the Test and Operations Physical Interface for ATM [Asynchronous Transfer Mode] standard. [UTOPIA Bus]