US 8,896,483 B2Granted

Method of automatic target angle tracking by monopulse radar under conditions of interference distorting location characteristic

OwnerEvgeny Markininventor

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Abstract

Method of automatic target angle tracking by sum-and-difference monopulse radar covers radiolocation sphere and specifically monopulse direction finding systems. It can be used in order to increase guidance accuracy, for example, for anti aircraft missiles and of unmanned aerial vehicles to radar targets such as: radio beacons; aerial vehicles reflecting the radio signal that illuminates them; aerial vehicles and ground-based devices radiating radio signals and jamming signals. The aim of the method consists in the assurance of reliability and stability and in the enhancement of guidance accuracy of automatic target angle tracking due to elimination of automatic tracking losses and great errors arising during the influence of the signals of orthogonal polarization or polarization close to it. The proposed method provides full protection from polarization jamming for all types of monopulse radars.

Claims7

Dependent claims

A method of automatic target angle tracking by monopulse radar under conditions of interference distorting location characteristic, said method comprising at least the following steps:

the reception of the signals from the target is carried out by a monopulse antenna by using sum and difference channels and the monopulse antenna has a vertical working polarization;
the difference signal amplitude and the phase difference between the signals of the sum and difference channels are measured, herewith the difference signal amplitude determines a value of an angular error signal, and the phase difference between the signals of the sum and difference channels determines a sign of the angular error signal;
the monopulse antenna is orientated in the direction of the target relying on the measured values of the amplitude and the phase difference signals corresponding to an angular error value and its sign;
an additional reception of signal component from the target on the polarization orthogonal or is close to orthogonal relative to the working polarization of said monopulse antenna, is performed;
the amplitude values of the additional and sum signals are compared;
when the amplitude value of the additional channel signal exceeds the amplitude value of the sum signal, the monopulse antenna is oriented relying on the angular error, the sign of which corresponds to the measured value of the phase difference between the sum and difference signals, the value is formed via the inverse transformation of the measured amplitude value of the difference signal.

3 more elements

A monopulse radar for target autotracking comprises

a monopulse antenna having a vertical working polarization;
the outputs of said monopulse antenna are connected to the appropriate inputs of a stripline ring providing at its outputs the shaping of microwave signals of the sum and difference channels;
the sum output of said stripline ring is connected to a mixer of the sum channel and the difference output of said stripline ring is connected to a mixer of the difference channel;
said mixers of the sum and difference channels are connected to a heterodyne which is also connected to a mixer of an additional channel;
the signal input of said mixer of the additional channel is connected to a horn antenna having a working polarization is orthogonal or close to orthogonal relative to the working polarization of said monopulse antenna;
the outputs of said mixers of the sum, difference and additional channels are connected to the inputs of intermediate-frequency amplifiers of the sum, difference and additional channels respectively;
the outputs of said intermediate-frequency amplifiers of the sum and difference channels are connected to the appropriate inputs of a phase detector on the output of which is formed an error signal;
the output of said phase detector through error-signal amplifier is connected to a drive mechanism of said monopulse antenna;
the outputs of said intermediate-frequency amplifiers of the sum and additional channels are connected through detectors of the sum and additional channels to the appropriate inputs of a comparator on the output of which is formed a control signal;
the output of said comparator is connected to a switching device (switch), the driving point of said switch, also called the control input of the switch, receives the control signal from the comparator;
the outputs of said intermediate-frequency amplifiers of the sum and difference channels are also connected to the appropriate inputs of said switch the output of the switch is connected to the input of an automatic gain control system;
the output of said automatic gain control system is connected to said intermediate-frequency amplifiers of the sum and difference channels.

9 more elements

A monopulse radar for target autotracking comprises

a monopulse antenna having a vertical working polarization;
the outputs of said monopulse antenna are connected to the inputs of a stripline ring providing at its outputs the shaping of microwave signals of the sum and difference channels;
the sum output of said stripline ring is connected to a mixer of the sum channel and the difference output of said stripline ring is connected to a mixer of the difference channel;
said mixers of the sum and difference channels are connected to a heterodyne which is also connected to a mixer of an additional channel;
the signal input of said mixer of the additional channel is connected to a horn antenna having a working polarization is orthogonal or close to orthogonal relative to the working polarization of said monopulse antenna;
the outputs of said mixers of the sum, difference and additional channels are connected to the inputs of intermediate-frequency amplifiers of the sum, difference and additional channels respectively;
the output of the intermediate-frequency amplifier of the sum channel is connected to the input of an automatic gain control system;
the output of said automatic gain control system is connected to said intermediate-frequency amplifiers of the sum and difference channels;
the outputs of said intermediate-frequency amplifiers of the sum and difference channels are connected to a phase detector on the output of which is formed an error signal;
the outputs of said intermediate-frequency amplifiers of the sum and additional channels are connected through detectors of the sum and additional channels to the corresponding inputs of a comparator on the output of which is formed a control signal;
the output of said comparator is connected to a switching device (switch), the control input of said switch, also called the driving point of the switch, receives the control signal from the comparator;
the output of the phase detector is connected to the signal input of said switch;
one output of said switch is connected to a drive mechanism of said monopulse antenna through an error-signal amplifier;
the other output of said switch is connected to the input of an analog-to-digital converter the output of which is connected through an arithmetic unit to the input of a digital-to-analog converter;
the output of said digital-to-analog converter is connected through said error-signal amplifier to said drive mechanism of said monopulse antenna.

12 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/837,461Filed 15 Jul 2010
Published: US 2012/0013500 A119 Jan 2012
Granted: 25 Nov 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G01S 3/08
Details: means for reducing polarisation errors, e.g. by use of Adcock or spaced loop antenna systems
G01S 3/325
Derived from different combinations of signals from separate antennas, e.g. comparing sum with difference: automatic tracking systems
H01Q 25/02
Antennas or antenna systems providing at least two radiating patterns: providing sum and difference patterns
G01S
Radio direction-finding