18WuD2x

inverse voltage • invister 379
negative half-cycle of ac input. 3. Semiconductorjunction
reverse voltage.
inverse Wiedeman effect See DIRECT WIEDE-
MAN EFFECT.
inversion 1. A reversal of the normal vertical temperature
gradient of the atmosphere, often resulting
in long-distance tropospheric radio-wave
propagation. 2. Speech scrambling (see SCRAM-
BLER CIRCUIT). 3. Phase inversion (see PHASE
INVERTER). 4. Changing direct current into alternating
current, often increasing the voltage
(see INVERTER, 1).
inverted amplifier A push-pull, grounded-gate,
field-effect-transistor (FET) amplifier.
D
inverter, 1
Input
S
Output
Input
Output
S
RFC
In
0
1
Out
1
0
D
+
inverted amplifier
inverted-L antenna An antenna having a horizontal
radiator and a vertical feeder or lead-in attached
to one end of the radiator. The entire
arrangement resembles an upside-down L. The
overall length is generally 1 ⁄4 to 1 ⁄2 wavelength.
inverted speech See SCRAMBLED SPEECH.
inverter 1. Also called power inverter. A device that
converts direct current (dc) into alternating current
(ac), often of a much higher voltage (e.g., 12
Vdc into 117 Vac). 2. A logic circuit that provides
an output pulse that is a negation of the input
pulse. Also called a COMPLEMENTER or a NOT
CIRCUIT. 3. See PHASE INVERTER.
inverting adder An analog adder circuit that is
provided with an amplifier for a 180° phase
shift.
inverting amplifier An amplifier providing a 180°
phase shift between input and output.
inverting connection Connection to the inverting
input terminals of a differential amplifier or operational
amplifier. Also see INVERTING INPUT.
Compare NONINVERTING INPUT.
inverting input In a differential amplifier or operational
amplifier, the input circuit that produces a
phase reversal between the input and output.
Compare NONINVERTING INPUT.
inverter, 2
inverting transponder In a communications
satellite, a transponder in which the downlink
band is “upside-down” in frequency relative to the
uplink band. That is, the highest downlink frequency
corresponds to the lowest uplink frequency,
and the lowest downlink frequency
corresponds to the highest uplink frequency.
Compare NONINVERTING TRANSPONDER. See
also DOWNLINK, TRANSPONDER, UPLINK.
invisible failure In a computer system, a hardware
or software failure whose effect on the system is
unnoticeable in a given application. A failure that
is invisible in one application might be vividly apparent
in some other application.
invister A unipolar semiconductor material, capable
of operation at very high frequencies.