Increasing emphasis is being placed on electronic countermeasures to reduce battlefield losses. Chaff is an effective ecm against noncoherent threat radars, but the effectiveness of chaff is considerably less when used against a doppler or mti radar. Self-protection chaff decelerates very rapidly to low doppler frequencies may be rejected by the radar tracking circuits. High doppler frequencies may be restored to chaff by using nonlinear dipoles and illuminating them with a modulating microwave source. The nonlinear dipoles act as remote mixers and reradiate synthetic doppler signals back to the threat radar. This program will develop the electrical and physical specifications for these dipoles. Research will be conducted in materials and processes to produce nonlinear dipoles meeting these specifications. Sample dipoles will then be manufactured and tested to determine their efficiency in producing adequate chaff doppler response in a threat radar. One or more ecm system techniques will be developed to take advantage of existing us army chaff dispensers, jamming equipment and doppler chaff.
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