HYBRID RINGA circular waveguide arrangement with four branches. When properly terminated,
energy is transferred from any one branch into any two of the remaining three branches.
HYBRID MIXERSee Balanced Mixer.
IF AMPLIFIERUsually a narrow-bandwidth IF amplifier that is tuned to one of the output
frequencies produced by the mixer.
INDEX OF REFRACTIONThe degree of bending of an rf wave when passing from one medium to
INDICATOREquipment that provides a visual presentation of target position information.
INSTANTANEOUS AUTOMATIC GAIN CONTROL (IAGC)Circuit that can vary the gain of the
radar receiver with each input pulse to maintain the output peak amplitude nearly constant.
INTERMEDIATE FREQUENCY (IF)A lower frequency to which an rf echo is converted for ease of
KEEP-ALIVE CURRENTSee Keep-Alive Voltage.
KEEP-ALIVE VOLTAGEDc voltage applied to a tr gap electrode to produce a glow discharge that
allows the tube to ionize faster when the transmitter fires.
KEYED-OSCILLATOR TRANSMITTERA transmitter in which one stage is used to produce the rf
KLYSTRON POWER AMPLIFIERMulticavity microwave electron tube that uses velocity
LIN-LOG AMPLIFIERAmplifier in which the response is linear for weak signals and logarithmic for
LINE OF SIGHTStraight line from a radar antenna to a target.
LINE-PULSING MODULATORCircuit that stores energy and forms pulses in the same circuit
element, usually the pulse-forming network (pfn).
LIQUID-COOLING SYSTEMSource of cooling for high-heat producing equipments, such as
microwave components, radar repeaters, and transmitters.
LOBEAn area of greater signal strength in the transmission pattern of an antenna.
LOGARITHMIC RECEIVERReceiver that uses a linear logarithmic amplifier (lin-log) instead of a
normal linear amplifier.
LOW-NOISE AMPLIFIERSee Preamplifier.
MAGIC TSee Balanced Mixer.
MAGNETRON OSCILLATORElectron tube that provides a high power output. Theory of operation
is based on interaction of electrons with the crossed electric and magnetic fields in a resonant cavity.