Device and method of using an auxiliary antenna outfitted with an adaptive space filter for anti-jamming a major associated antenna
AssigneeContre Mesure Hyperfrequence
InventorClaude Chekroun
Life of this patent
Estimating the term…
Abstract
The invention pertains to the sensing and elimination of jamming signals transmitted by jammers towards radar antennas. According to the invention, we associate with a main space surveillance radar antenna an auxiliary antenna that is outfitted with a modulating filter which enables the sensing of jammers, and the elimination of jamming effects by opposing, to the secondary lobes of the main antenna corresponding to the jamming directions, corresponding secondary lobes which are appropriately amplified by the auxiliary antenna. The invention applies to anti-jamming of radar antennas with mechanical or electronic sweeps.
Claims6
A method of searching and assessing the position of at least one jammer transmitting towards a radar antenna, the pointing axis of the radar antenna being shifted in relation to the straight line connecting the antenna to the jammer, the method comprising the steps of:
- placing a filter in front of the antenna, the filter including at least one network of conductive wires having added thereto appropriately arranged and distributed diodes for enabling modulation in response to the amplitude of secondary lobes from the radiation pattern of the antenna;
- modulating currents traveling through the wires for shifting at least one overintensification by increasing by at least 10 to 15 decibles the level of one secondary lobe angularly distant by angle .theta. to the aiming direction of the antenna;
- assessing and noting at all times the value of angle .theta., angle .theta. being a function of the modulated currents applied to the network;
- assessing and noting the noise level picked up by the antenna for each value of angle .theta.;
- and
- deducing the direction of the jammer from the pick-up peak noise levels.
Apparatus for searching and assessing the position of at least one transmitting jammer comprising:
- a first radar antenna having a pointing axis shifted in relation to the straight line connecting the antenna to the jammer;
- a filter placed in front of the first antenna, the filter including at least one network of conductive wires having added thereon appropriately arranged and distributed diodes for enabling modulation in response to the amplitude of secondary lobes from the radiation pattern of the first antenna;
- a second main radar antenna including a pick-up circuit;
- and
- adding means for adding, at the level of signals picked up by the main antenna, modulated pick-up signals derived from the auxiliary antenna;
- thereby eliminating jamming effect on the main antenna.
Dependencies are inferred from the claim text.