## Electronics (Mike Jaroch)

Note: You may download the entries for this glossary here. If you wish to use this in your own Moodle course, first make a blank glossary and then follow the instructions for importing glossary entries here.

Browse the glossary using this index

Special | 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 | ALL

Page:  1  2  (Next)
ALL

### U

#### ULTRAHIGH FREQUENCY

The band of frequencies from 300 megahertz to 3 gigahertz [17].
 Keyword(s): ULTRAHIGH FREQUENCY

#### ULTRASONIC

(1) Sounds above 20,000 hertz [10]. (2) Supersonic.
 Keyword(s): ULTRASONIC

#### UNBALANCED CRYSTAL MIXER

A circuit consisting of a section of coaxial transmission line one-half wavelength long that is tuned to the difference (intermediate) frequency between the local oscillator and RF echo signals [18].

 Keyword(s): UNBALANCED CRYSTAL MIXER

#### UNIDIRECTIONAL

In one direction only [1].
 Keyword(s): UNIDIRECTIONAL

#### UNIDIRECTIONAL ARRAY

An antenna array that radiates in only one general direction [10].
 Keyword(s): UNIDIRECTIONAL ARRAY

#### UNIJUNCTION TRANSISTOR

(UJT)—A three-terminal, semiconductor device with a negative resistance characteristic that is used in switching circuits, oscillators, and wave-shaping circuits [7]

 Keyword(s): UNIJUNCTION TRANSISTOR , UJT

#### UNIT

(1) An assembly or any combination of parts, subassemblies, and assemblies mounted together. Normally capable of independent operation [17]. (2) A single object or thing [13].

 Keyword(s): UNIT

#### UNIT SIZE

The standards adopted to make comparisons between things of like value (for example, the unit size for conductors is the mil-foot) [4].

 Keyword(s): UNIT SIZE

#### UNIVERSAL TIME CONSTANT CHART

A chart used to find the time constant of a circuit if the impressed voltage and the values of R and C or R and L are known [2].

 Keyword(s): UNIVERSAL TIME CONSTANT CHART

#### UNTUNED LINE

Another name for the flat or nonresonant line [10].
 Keyword(s): UNTUNED LINE

Page:  1  2  (Next)
ALL