Airborne radar jamming system

摘要

A radar jamming signal generated by equipment carried by a target aircraft, is launched onto the leading end of a towed single wire transmission line so as to travel the length of the line as a nonradiating surface wave. A drogue radiator is attached to the trailing end of the line for radiating the jamming signal transversely of the towed line so as to be received by and cause jamming of tracking and/or fire control radar. The length of the single wire transmission line is selected so that the trailing radiator causes the jamming signal to emanate from a position sufficiently behind the aircraft so as to be outside the destructive radius of weapon fire directed at the apparent source of the jamming signal by fire control radar. A ventriloqual-like deception of the radar is thus achieved. A wave launcher couples the jamming signal to the leading end of the transmission line and for this purpose includes an electrically conducted horn-shaped structure, a tunable coaxial feed end at the constricted end of the horn structure, an inner transition conductor connecting the inner conductor of the coaxial feed to a leading end of the single wire transmission line, and a plurality of annular dielectric lenses and dielectric guides cooperatively shaped and fitted to the horn structure in a manner that effectively matches the bounded electromagnetic transmission wave characteristics of the coaxial feed cable with the surface wave transmission characteristics of the single wire transmission line. Coacting with the ventriloqual-like radiation of the jamming signal from the trailing end of the transmission line is an anti-integration network that hides the return radar signal reflected off the target aircraft in a signal energy “hole” created for such purpose in a secondary low level noise signal transmitted directly from the aircraft.

主权项

1. A method of radar jamming comprising the combination of steps of:
transmitting a first signal of suitable frequency content and power level for radar jamming from a signal radiator adjacent the trailing end of an elongate transmission line towed by an aircraft in which said first signal is a noise signal transmitted at a predetermined power level; concurrently transmitting a second signal of noise content from a transmitting location proximate the aircraft; receiving a transmitted radar signal at such aircraft; selectively modifying the transmission of said second signal so as to reduce its output level at times determined by the receipt of a transmitted radar signal so that the composite signal energy of the second signal and a reflection by the body of such aircraft of a transmitted radar signal is substantially uniform during the time of the reflected radar signal and such composite signal energy is superimposed by said first signal radiated from said radiator towed by the aircraft; and wherein said predetermined power level of said first signal is selected to be substantially greater than an unreduced normal output level of said second signal so that the combined first and second signals have an apparent point of origin at a position along said transmission line that lies closer to said signal radiator than to the body of the aircraft.