"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"
Previous set of 'Fa' Radar terms
FREQUENCY AGILITY: A radar's ability to change frequency within its operating band, usually on a pulse-topulse
basis. This is an ECCM technique employed to avoid spot jamming and to force the jammer to go into a less effective barrage mode.
FREQUENCY AGILITY RADAR: A radar that automatically or semi-automatically tunes through a discrete set of operating frequencies in its normal mode of operation.
FREQUENCY COMPENSATION NETWORK: Circuit modification used to improve or broaden the
linearity of its frequency response.
FREQUENCY DIVERSITY RADAR: A radar system technique, employed primarily as an anti-jamming feature, where the transmitter output frequency varies randomly from pulse to pulse over a wide frequency range.
FREQUENCY RANGE: A specifically designated portion of the frequency spectrum; of a device, the band
of frequencies over which the device may be considered useful with various circuit and operating conditions; of a
transmission system, the frequency band in which the system is able to transmit power without attenuating or distorting it more than a specified amount.
FREQUENCY SCANNING: Varying the output frequency to achieve electronic scanning.
FREQUENCY SHIFT KEYING (FSK): A form of FM where the carrier is shifted between two frequencies in accordance with a predetermined code. In multiple FSK, the carrier is shifted to more than two frequencies. FSK is used principally with teletype communications.
FREQUENCY SPECTRUM: In a radar, the entire range of frequencies contained in an rf pulse or
signal.
FREQUENCY SYNTHESIZER: A bank of oscillators in which the outputs can be mixed in various
combinations to produce a wide range of frequencies.
"FRUIT": In a radar beacon system, there is a type of interference called "FRUIT", caused by beacon replies to interrogation asynchronous with the observer's interrogator. The largest amount of this interference is received through the side-lobes of the interrogating antenna, but it can become dense enough to cause false target indications.
FTC (FAST TIME CONSTANT): An anti-jam feature employed in radar systems where receiver circuits may be
selected to provide a short time constant to emphasize signals of short duration to produce discrimination against the low frequency components of clutter.
FUNDAMENTAL FREQUENCY: Used synonymously for tuned frequency, carrier frequency, center frequency,
output frequency, or operating frequency.
FUSELAGE STATION: A reference point (usually the nose of an aircraft) used to measure or identify fore and aft locations. One of several aircraft location designations - also see butt line and water line.
