PL168514B1 - A system for collecting interference signals in a multi-beam radar antenna - Google Patents

Abstract

A system for collecting interference signals in a multi-beam radiolocation antenna, consisting of an RF signal combiner, a phase equalization system and directional couplers, characterized in that the main paths of the directional couplers (4) are connected to the outputs of the multi-beam antenna (1) and are connected on the other side to the inputs of the receivers (6), while the decoupled paths of these couplers are closed on one side with matched loads (5) and on the other side are connected to the inputs of the phase equalization system (2), the outputs of which are connected to the inputs of the RF signal combiner (3), wherein the signals in the combiner (3) are added in amplitude ratios corresponding to the amplitude distribution at the outputs of the multi-beam antenna (1) with identical phase shifts, while the phase equalization systems (2) introduce phase shifts compensating the phase distribution at the outputs of the multi-beam antenna (1).

Description

The subject of the invention is a system for collecting jamming signals in a multi-beam radar antenna.

In modern radiolocation technology, a very important parameter of the radar is its resistance to interference with high-frequency signals.

Jamming signals can originate from random sources within the search area. They are most often emitted by an enemy to disrupt the device's operation, reducing the radar's operating range. With very strong jamming, this range can be reduced to zero.

There are known methods of increasing the radar's resistance to interference by using systems that detect these interferences, e.g. by quickly changing the operating frequency on which they occur or by switching off the device in the space sector in which they occur.

Known interference signal collection systems consist of a phase equalization system, an RF signal combiner and directional couplers.

The interference detection system is incorporated into the radar's receiving path in a way that does not distort the receiving beam. It should also not introduce any loss of the receiving signal.

In radars with a multi-beam receiving antenna with a significant number of beams, reaching up to several dozen antenna receiving paths, the inclusion of a system detecting interference in the area of the entire receiving beam requires the use of a very large number of complicated systems with a very large number of components, which automatically increases the cost of the entire device and reduces its reliability.

The interference signal collection system of the invention is distinguished by the fact that the outputs of the multibeam receiving antenna are connected to the main paths of directional couplers, which are connected to the inputs of the station receivers. The decoupled paths of these couplers are terminated with matched loads on one end and connected to the inputs of a phase equalizer, whose outputs are connected to the inputs of the RF signal combiner. The signals in the combiner are summed at amplitude ratios corresponding to the amplitude distribution at the multibeam antenna outputs with identical phase shifts, while the phase equalizers introduce phase shifts to compensate for the distribution at the antenna outputs.

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The solution according to the invention allows the use of a simple system in which the number of input paths is limited to the number of receiving beams, while at the same time controlling the full receiving antenna characteristics.

The system for collecting jamming signals in a multi-beam radar antenna in an example embodiment is shown in the drawing, which is its block diagram.

Beamforming system 1, operating in the low-frequency band, is part of a multi-beam flat antenna system. This system shapes a fan of beams in the elevation plane. Output signals from beamforming system 1 are fed, through couplers 4, to the receiving heads 6 of the radar receivers. Portions of the signals are transmitted through the decoupled arms of directional couplers 4 to phase equalization system 2, while on the other side, the decoupled path of couplers 1 is closed with matched loads 5. Phase equalization system 2 introduces a phase shift in the signals compensating the phase distribution at the outputs of beamforming system 1. Output signals from phase equalization system 2 are summed in adder 3 at amplitude ratios corresponding to the amplitude distribution at the multi-beam antenna outputs with identical phase shifts, while phase equalization systems 2 introduce phase shifts compensating the phase distribution at the antenna outputs.

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Publishing Department of the Polish Patent Office. Circulation: 90 copies. Price: PLN 1.50.

Claims (1)

Patent claim A system for collecting interference signals in a multi-beam radar antenna, consisting of a bw signal combiner, phase alignment system and directional couplers, characterized in that the main paths of the direction couplers (4) are connected to the inputs of the receivers to the outputs of the multi-beam antenna (1) (6), while the decoupled paths of these couplers are on the one hand closed with matched loads (5), and on the other hand they are connected to the inputs of the phase alignment circuit (2), the outputs of which are connected to the inputs of the bwcz signal combiner. (3), where the signals in the adder (3) are summed up in the amplitude ratios corresponding to the amplitude distribution at the outputs of the multi-beam antenna (1) with the same phase shifts, while the phase alignment systems (2) introduce phase shifts compensating the phase distribution at the outputs of the multi-beam antenna ( 1).