AI-2
BLIP—See Pip.
BLOCKING—A condition in an amplifier, caused by overdriving one or more stages, in which the
amplifier is insensitive to small signals immediately after reception of a large signal.
BROADSIDE ARRAY—An antenna array in which the direction of maximum radiation is
perpendicular to the plane of the array.
BUFFER AMPLIFIER STAGE—Amplifier stage that isolates one circuit from another.
CARRIER FREQUENCY—The frequency of an unmodulated transmitter output.
CARRIER-CONTROLLED APPROACH—Shipboard radar system used to guide aircraft to safe
landings in poor visibility conditions.
CLUTTER—Confusing, unwanted echoes that interfere with the observation of desired signals on a
radar indicator.
COHERENCE—A definite phase relationship between two energy waves, such as transmitted frequency
and reference frequency.
COHERENT OSCILLATOR—In cw radar this oscillator supplies phase references to provide coherent
video from target returns.
CONICAL SCANNING—Scanning in which the movement of the beam describes a cone, the axis of
which coincides with that of the reflector.
CONTACT—In radar, an object that reflects rf energy; target.
CORNER REFLECTOR—Two flat reflectors that meet at an angle and are normally fed by a half-wave
radiator.
CROSSED-FIELD AMPLIFIER—High-power electron tube that converts dc to microwave power by a
combination of crossed electric and magnetic fields.
CYLINDRICAL PARABOLIC REFLECTOR—A parabolically shaped reflector that resembles part
of a cylinder.
DEFLECTION COILS—In a cathode-ray tube, coils used to bend an electron beam a desired amount.
DEIONIZATION TIME—In a spark gap, the time required for ionized gas to return to its neutral state
after the spark is removed.
DESIGNATION—Operational phase of a fire- control or track radar during which the radar is directed
to the general direction of a desired target.
DIFFERENCE FREQUENCY—See Beat Frequency.
DIODE DETECTOR—A demodulator that uses one or more diodes to provide a rectified output with an
average value that is proportional to the original modulation.
DIRECTIONAL ANTENNA—An antenna that radiates most effectively in only one direction.
DIRECTIVITY—Ability of an antenna to radiate or receive more energy in some directions than in
others. The degree of sharpness of the antenna beam.
