RU2764000C1 - Method for forming a directional diagram - Google Patents

Abstract

FIELD: antenna technology.

SUBSTANCE: invention relates to antenna technology and is intended for constructing a narrow radiation pattern in receiving phased antenna arrays. Essence: in the method, a signal is received by means of an antenna array, if necessary, narrowing the radiation pattern in the horizontal plane, the left R_L and right R_R rays of the radiation pattern are formed, the S_LR sum beam is calculated as the sum of the modules of the left R_L and right R_R rays in the form of S_LR=a|R_L|+b|R_R|, where a+b=2, the D_LR difference beam is calculated as the difference of the modules of the left R_L and right R_R rays in the form of D_LR =|R_L-R_R|, after which the narrowed beam is calculated in the horizontal plane R_LR in the form

, where 0<n<2. If it is necessary to narrow the radiation pattern in the vertical plane, the upper R_U and lower R_B rays of the radiation pattern are formed, the S_UB sum beam is calculated as the sum of the modules of the upper R_U and lower R_B rays in the form of S_UB=а'|R_U|+b'|R_B|, where a'+b'=2, the D_UB difference beam is calculated as the modulus of the difference of the upper R_U and lower R_B rays in the form of D_UB=|R_U-R_B|, after which the narrowed beam R_UB in the vertical plane is calculated in the form

, where 0 <m<2. In the case of the narrowing of the radiation pattern in both planes the resulting radiation pattern is found as

, where 0<q<∞, 0≤с≤2, 0≤p≤2, с+р=2 or as

, where 1≤g≤2. In the case of the narrowing of the radiation pattern in the horizontal plane, the left and right rays of the radiation pattern are formed, proceeding from the required direction of the narrowed beam in the horizontal plane θ₀, respectively, in the directions θ₀-θ_н/2 and θ₀+θ_н/2 by the weight summation of the outputs of all elements of the antenna array, while θ_н is the angle of spacing between the beams. In the case of the narrowing of the radiation pattern in the vertical plane of the upper and lower rays of the radiation pattern is formed, proceeding from the required direction of the narrowed beam in the vertical plane ϕ₀, directions ϕ₀+ϕ_V2 and ϕ₀-ϕ_V2 by weighted summation of the outputs of all elements of the antenna array, while ϕ_V is the angle of spacing between the beams. To form a multbeam radiation pattern with narrowed beams, an appropriate number of pairs of beams are formed for a linear configuration of the antenna array, and for a flat configuration of the antenna array, an appropriate number of left, right, upper and lower beams are formed from which the narrowed resulting beams are formed.

EFFECT: increase in the gain of the antenna array due to the use of the entire area of the antenna array to form a radiation pattern.

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Description

The invention relates to antenna technology and is intended for constructing a narrow radiation pattern (DN) in receiving phased antenna arrays.

A known method of forming the radiation pattern [1 - pp. 295, 296 - Burdik B.C. Analysis of hydroacoustic systems. L.: Shipbuilding, 1988], which consists in receiving the reflected signal through the antenna array, the time delay of the output signals of the array elements and their subsequent summation.

The disadvantage of this method is the complexity of its practical implementation, due to the presence of technical problems, which are mainly associated with the need to implement a large number of stable, identical and tunable analog delay lines.

Also known is a method of forming a radiation pattern [2 - Knight W.S. Pridem R.G. and Kay S.M. Digital signal processing in sonar systems. TIER, vol. 69, N 11, 1981, p. 107], which consists in receiving the signal S(t) by means of a flat antenna array, sampling the output signals of the antenna array elements, two-stage formation of beams of the radiation pattern separately in the azimuth and elevation planes. According to this method, the output signal x _mn (t) of an arbitrary element with the number (t, n) of the antenna array with a size of M*N elements is converted into a time series x _{mn (iTd) of samples by sampling with a frequency Fd l} (where i is the sample number) , i.e. samples x _mn (t), taken with a sampling step Td=(F _d ) ^-1 . The formation of beams of the radiation pattern in the known method is based on the compensation of time delays between the moments of arrival of the front of the received wave on the array elements separately in the azimuthal and elevation planes, by delaying the samples x _mn (iTd) for a time multiple of Td. In this case, the output signal b(iTd) of any beam from the generated set of beams of the radiation pattern also represents a time series.

The disadvantage of this method is the limited accuracy of beamforming. The limitation of accuracy is due to the fact that this method allows the formation of only "synchronous" beams of the radiation pattern, i.e. those for which the values of the arrival delay times of the front of the received wave are multiples of the sampling step Td.

The closest in technical essence to the invention is a method for forming a radiation pattern [3 - US patent 6921096 G01S 3/28, 2000], adopted as a prototype, which consists in dividing the radiators of the antenna array into several identical subarrays containing at least one radiator , the first pair of subarrays is located on the sides of the first axis of the antenna array Y, the second pair of subarrays is located on the sides of the second axis of the antenna array X, while the angle between the X and Y axes is not equal to zero, the sum of the signals from the outputs of the emitters of the first R _L and the second R is calculated _R sub-arrays from the first pair of sub-arrays and the sum of signals from the outputs of the emitters of the third R _U and fourth R _B sub-arrays from the second pair of sub-arrays, calculate the first total beam as the sum of modules S _LR =a|R _L |+b|R _R |, where a+ b=2, the second sum beam as the sum of modules S _UB =a'|R _U |+b'|R _B |, where a'+b'=2, the first difference beam as the modulus of difference D _LR =|R _L -R _R |, the second difference ray as the modulus of the difference D _UB =|R _U -R _B |.

, где 0<n<2, суженный луч во второй плоскости как

, где 0<m<2. Вычисляют результирующий луч как

, где 0<q<∞, 0≤с≤2, 0≤р≤2, с+р=2, или как

, где 1≤g≤2.Calculate the narrowed beam in the first plane as

, where 0<n<2, narrowed beam in the second plane as

, where 0<m<2. Calculate the resulting ray as

, where 0<q<∞, 0≤c≤2, 0≤p≤2, c+p=2, or as

, where 1≤g≤2.

, где 0<n<∞.For the case of a linear grating, two identical sublattices are used, for which the sum of the signals from the outputs of the emitters of the first R _L and the second R _R sublattices is calculated, the total beam is found as the sum of the modules S=a|R _L |+b|R _R |, where a+b =2, the difference beam is found as the modulus of the difference D=|R _L -R _R |, and the narrowed beam is calculated as

, where 0<n<∞.

The disadvantages of the prototype include:

- use for the formation of rays only part of the antenna array. So, to form the left beam _RL , one subarray (left half) of the antenna array is used, and to form the right beam _RR , another subarray (right half) of the antenna array is used, which increases the width of the resulting beam and reduces the gain. So, when a narrowed pattern is formed in one plane, the antenna array is divided into two sub-arrays, while K _{y decreases by a} factor of two, and in the case of a narrowed pattern in two planes, the antenna array is divided into four sub-arrays, while K _y decreases by four times;

- the impossibility of forming a multi-beam pattern with independently controlled beams, since the beams are formed by simply summing the signals from the sub-arrays. However, modern communication and radar systems often require the creation of multibeam RPs, for example, in the form of a fan of beams.

The technical problem to be solved by the present invention is to ensure the formation of a multi-beam pattern with independent beam control.

, где 0<n<2, в случае необходимости сужения диаграммы направленности в вертикальной плоскости, формируют верхний R_U и нижний R_B лучи диаграммы направленности, вычисляют суммарный луч S_UB как сумму модулей верхнего R_U и нижнего R_B лучей в виде S_UB=a'|R_U|+b'|R_B|, где a'+b'=2, вычисляют разностный луч D_UB как модуль разности верхнего R_U и нижнего R_B лучей в виде D_UB=|R_U-R_B|, после чего вычисляют суженный луч R_UB в вертикальной плоскости в виде

, где 0<m<2, в случае сужения диаграммы направленности в обеих плоскостях находят результирующую диаграмму направленности как

, где 0<q<∞, 0≤с≤2, 0≤р≤2, с+р=2 или как

, где 1≤g≤2.To solve this technical problem, a method for forming a radiation pattern is proposed, in which a signal is received by means of an antenna array, if it is necessary to narrow the radiation pattern in the horizontal plane, the left R _L and right R _R beams of the radiation pattern are formed, the total beam S _{LR is} calculated as the sum of the modules of the left R _L and right R _R rays in the form S _LR =a|R _L |+b|R _R |, where a+b=2, calculate the difference ray D _LR as the modulus of the difference of the left R _L and right R _R rays in the form D _LR = |R _L -R _R |, after which the narrowed beam in the horizontal plane R _LR is calculated as

, where 0<n<2, if it is necessary to narrow the radiation pattern in the vertical plane, form the upper R _U and lower R _B beams of the radiation pattern, calculate the total beam S _UB as the sum of the modules of the upper R _U and lower R _B beams in the form S _UB =a'|R _U |+b'|R _B |, where a'+b'=2, calculate the difference ray D _UB as the modulus of the difference between the upper R _U and lower R _B rays in the form D _UB =|R _U -R _B |, after which the narrowed beam R _UB is calculated in the vertical plane in the form

, where 0<m<2, in the case of narrowing of the radiation pattern in both planes, the resulting radiation pattern is found as

, where 0<q<∞, 0≤c≤2, 0≤p≤2, c+p=2 or as

, where 1≤g≤2.

According to the invention, in the case of narrowing the radiation pattern in the horizontal plane, the left and right rays of the radiation pattern are formed based on the required direction of the narrowed beam in the horizontal plane θ ₀ , respectively, in the directions θ ₀ -θ _n /2 and θ ₀ +θ _n /2 by weighted summation of signals from the outputs of all elements of the antenna array, while θ _n is the separation angle between the beams, in the case of a narrowing of the radiation pattern in the vertical plane, the upper and lower rays of the radiation pattern are formed based on the required direction of the narrowed beam in the vertical plane ϕ ₀ , in the directions ϕ ₀ +ϕ _V /2 and ϕ ₀ -ϕ _V /2 by weighted summation of signals from the outputs of all elements of the antenna array, while ϕ _V is the separation angle between the beams, to form a multipath radiation pattern with narrowed beams for a linear configuration of the antenna array form the corresponding number of pairs of beams, and for a flat configuration of the antenna array, the corresponding the number of left, right, upper and lower beams from which the narrowed resulting beams are formed.

The technical result of the proposed method is to increase the gain of the antenna array by using the entire area of the antenna array to form the radiation pattern.

The comparative analysis of the claimed method and the prototype shows that their difference is as follows:

- in the prototype, the formation of rays is carried out by summing the signals from part of the antenna array, for this the antenna array is divided into sub-arrays, for a linear array configuration - into two sub-arrays, left and right, for a rectangular or other configuration of the antenna array - into four sub-arrays - left, right , upper and lower, in the proposed method for the formation of beams, the weight summation of signals from the entire antenna array is used, while for a linear array two independent beams are formed - right and left, the maxima of which are spaced apart by applying the appropriate weighting coefficients by an angle θ _n , and for a rectangular array or another configuration of the antenna array, in addition to the right and left beams, additional upper and lower beams are formed, the maxima of which, by applying the appropriate weighting factors, are spaced apart by an angle ϕ _V ;

- since in the prototype the formation of rays is carried out by a simple summation of signals from the sublattices, there is no possibility of creating a multi-beam DN with independently controlled beams. While in the proposed device, the formation of beams is carried out by weight summation of signals from all elements of the antenna array, therefore, using the appropriate weighting factors, it is possible to create a multi-beam DN with independent beam control.

The combination of distinguishing features and properties of the proposed method for the formation of DN from the literature is not known, so it meets the criteria of novelty and inventive step.

The figure shows a block diagram of a device that implements the proposed method.

When implementing the proposed method, the following sequence of actions is performed:

, где 0<n<2 - 1;- receiving a signal via an antenna array when needed narrowing the directivity pattern in a horizontal plane is formed Left R _L and right _R R rays directivity pattern is calculated total beam S _LR as the sum of the moduli of the left R _L and right _R R rays as S _LR = a | R _L |+b|R _R |, where a+b=2, calculate the difference beam D _LR as the modulus of the difference between the left R _L and right R _R beams in the form D _LR =|R _L -R _R |, after which the narrowed ray in the horizontal plane R _LR in the form

, where 0<n<2 - 1;

, где 0<m<2 - 2;- if it is necessary to narrow the radiation pattern in the vertical plane, form the upper R _U and lower R _B rays of the radiation pattern, calculate the total beam S _UB as the sum of the modules of the upper R _U and lower R _B rays in the form S _UB =a'|R _U | +b'|R _B |, where a'+b'=2, calculate the difference beam D _UB as the modulus of the difference between the upper R _U and lower R _B beams in the form D _UB =|R _U -R _B |, after which the narrowed ray R _UB in the vertical plane as

, where 0<m<2 - 2;

, где 0<q<∞, 0≤с≤2, 0≤р≤2, с+р=2 или как

, где 1≤g≤2 - 3;- in the case of a narrowing of the radiation pattern in both planes, the resulting radiation pattern is found as

, where 0<q<∞, 0≤c≤2, 0≤p≤2, c+p=2 or as

, where 1≤g≤2 - 3;

- in the case of a narrowing of the radiation pattern in the horizontal plane, the left and right beams of the radiation pattern are formed based on the required direction of the narrowed beam in the horizontal plane θ ₀ , respectively, in the directions θ _o -θ _n /2 and θ _o +θ _n /2 by weight summation signals from the outputs of all elements of the antenna array, while θ _n - the separation angle between the beams - 4;

in the case of a narrowing of the radiation pattern in the vertical plane, the upper and lower beams of the radiation pattern are formed, based on the required direction of the narrowed beam in the vertical plane ϕ ₀ , in the directions ϕ ₀ +ϕ _V /2 and ϕ ₀ -ϕ _V /2 by weighted summation of signals from outputs of all elements of the antenna array, with ϕ _V - separation angle between the beams - 5;

- to form a multipath radiation pattern with narrowed beams for a linear configuration of the antenna array, an appropriate number of pairs of beams is formed, and for a flat configuration of the antenna array, the corresponding number of left, right, upper and lower beams, from which the resulting narrowed beams are formed - 6.

A variant of the receiving antenna array (AR) that implements the proposed method includes (figure) M receiving channels 1, each of which includes a series-connected antenna element (AE) 2, a radio receiver (RP) 3 and an analog-to-digital converter (ADC) ) 4, the sampling input of which is connected to one of the outputs of the sampling signal generator (G) 5, and the data output is connected to one of the data inputs of the digital processing device (DSP) 6, the output of which is the output of the device.

RP 3 for operation of the device in the range of meter waves can be made in the form of a band-pass filter and an amplifier. In a higher frequency range, RP 3 additionally includes a mixer and a local oscillator. In this case, nodes can be used, for example, from [4 - pp. 142-143. Mini Circuits. RF & Microwave components guide. 2010].

G 5 represents a frequency synthesizer that provides the formation of a sampling signal Fd. In this case, for example, a synthesizer from [4 - pp. 142-143] can be used. The synthesizer signal is branched into M outputs using power dividers [4 - pp. 136-140].

UTSOS 6 is a computer that provides processing of signal samples according to a given algorithm.

To implement the proposed method, the following steps are performed, implemented in the device in the figure.

AE 2 of each receiving channel 1 converts the energy of the electromagnetic field into the energy of high-frequency currents supplied to the input of the RP 3, where the received signal is amplified, and, if necessary, frequency conversion and demodulation. The output signal of the RP 3 is fed to the input of the ADC 4, the output of which is formed by a sequence of digital samples of the received signal, taken at a frequency specified by the sampling signal generator (G) 5 S _mn (t).

From the obtained digital readings, a multibeam DN is formed by weight summation in the UDC 6. The number of generated beams is determined by the required number of narrowed beams.

For the case of a flat rectangular APAR, the aperture of which contains N _x AE 2, installed along the X coordinate at a distance d _x , and N _y AE 2, installed along the Y coordinate, at a distance d _y , readings of the i-th beam, with the maximum direction ϕ _i ,θ _i are calculated by multiplying the digital stream from each receiving channel 1 by the weight factor W _mn {(ϕ _i ,θ _i ) and summing. The radiation pattern (DN) for the i-th beam R(ϕ _i ,θ _i ) is defined as [5 - pp. 27-28, Kuzmin S.Z. Digital radar. Introduction to theory. Kiev. 2000 - 420 p.]:

where

If necessary, Nam constriction in the horizontal plane form the left and right R _{L R} R Nam rays by the expression (1) based on the desired direction of beam narrowed in the horizontal plane θ _o, respectively in the directions of θ _L = θ _n -θ _o / 2 and θ _n =θ _o +θ _n /2, where θ _n is the separation angle between the beams, equal to the width of the left and right DN beams in the horizontal plane.

The total beam S _{LR is} calculated as the sum of the moduli of the left _RL and right R _R beams in the form S _LR =a|R _L |+b|R _R |, where a+b=2, the difference beam D _{LR is} calculated as the modulus of the difference of the left R _L and right R _R beams in the form D _LR =|R _L -R _R |, after which the narrowed beam in the horizontal plane R _LR is calculated in the form

where 0<n<2.

If it is necessary to narrow the DN in the vertical plane, the upper R _U and lower R _B beams of the DN are formed according to expression (1), based on the required direction of the narrowed beam in the vertical plane ϕ ₀ , in the directions ϕ _U =ϕ _o +ϕ _V /2 and ϕ _B =ϕ ₀ -ϕ _V /2, where ϕ _V is the separation angle between the beams, equal to the width of the upper and lower DN beams in the vertical plane.

The total beam S _{UB is} calculated as the sum of the modules of the upper R _U and lower R _B beams in the form

S _UB =a'|R _U |+b'|R _B |,

where a'+b'=2,

the difference beam D _{UB is} calculated as the modulus of the difference of the upper R _U and lower R _B beams in the form D _UB =|R _U -R _B |, after which the narrowed beam R _UB in the vertical plane is calculated in the form

where 0<m<2.

In the case of narrowing of the RP in both planes, the narrowed beam of the resulting RP is found as

where 0<q<∞, 0≤с≤2, 0≤р≤2, с+р=2

or how

where 1≤g≤2.

To form a multi-beam RP containing K narrowed beams in the case of a linear configuration of the antenna array, an appropriate number of pairs of beams is formed according to expression (1), equal to the number of narrowed beams of the multi-beam RP in the required directions. In the case of a flat configuration of the antenna array, the corresponding number of left, right, upper and lower beams is formed according to expression (1), from which narrowed resulting beams are formed in the required directions.

The generated readings To the narrowed beams from the output of the UTsOS 6 are transmitted to the output of the device.

Modeling shows that the method provides narrowing of the DN at least 2 times for m=1, q=1 and at least 10 times for m=1, q=0.5.

The proposed method provides the formation of a multi-beam pattern with narrowed beams and the possibility of independent restructuring of the direction of these rays, while in the prototype, a pattern is formed with only one fixed narrowed beam.

The proposed method provides an increase in the gain DN K _y compared to the prototype, since the beams are formed from the entire antenna array, while in the prototype beams are formed using separate sub-arrays, the area of \u200b\u200bwhich is less than the area of the entire antenna array. So, in the prototype, when forming a narrowed pattern in one plane, the antenna array is divided into two sub-arrays, while K _y decreases by half, and in the case of the formation of a narrowed pattern in two planes, the antenna array is divided into four sub-arrays, while K _y decreases four times.

The performance of the proposed method was tested on a mock-up antenna array. Tests showed the coincidence of the obtained characteristics with the calculated ones.

Claims (1)

A method for forming a radiation pattern, in which a signal is received by means of an antenna array, if it is necessary to narrow the radiation pattern in the horizontal plane, the left _RL and right R _R beams of the radiation pattern are formed, the total beam S _{LR is} calculated as the sum of the modules of the left _RL and right R _R beams in in the form S _LR =a|R _L |+b|R _R |, where a+b=2, calculate the difference beam D _LR as the modulus of the difference between the left _RL and right R _R beams in the form D _LR =|R _L -R _R |, after which the narrowed beam in the horizontal plane R _LR is calculated in the form

, where 0<n<2, if it is necessary to narrow the radiation pattern in the vertical plane, form the upper R _U and lower R _B beams of the radiation pattern, calculate the total beam S _UB as the sum of the modules of the upper R _U and lower R _B beams in the form S _UB = a'|R _U |+b'|R _B |, where a'+b'=2, calculate the difference ray D _UB as the modulus of the difference between the upper R _U and lower R _B rays in the form D _UB =|R _U -R _B |, after which the narrowed beam R _UB is calculated in the vertical plane in the form

, where 0<m<2, in the case of narrowing of the radiation pattern in both planes, the resulting radiation pattern is found as

, where 0<q<∞, 0≤c≤2, 0≤p≤2, c+p=2 or as

, where 1≤g≤2, characterized in that in the case of narrowing the radiation pattern in the horizontal plane, the left and right beams of the radiation pattern are formed based on the required direction of the narrowed beam in the horizontal plane θ ₀ , respectively, in the directions θ ₀ -θ _H /2 and θ ₀ + θ _H /2 by weight summing the signals from the outputs of all elements of the antenna array, while θ _H is the separation angle between the beams, in the case of a narrowing of the radiation pattern in the vertical plane, the upper and lower beams of the radiation pattern are formed based on the required direction of the narrowed beam in the vertical plane ϕ ₀ , in the directions ϕ ₀ + ϕ _V /2 and ϕ ₀ -ϕ _V / 2 by weighted summation of signals from the outputs of all elements of the antenna array, while ϕ _V is the separation angle between the beams, to form a multi-beam radiation pattern with narrowed beams for a linear configuration of the antenna array, the corresponding number of pairs of beams is formed, and for a flat configuration of the antenna array - the corresponding number of left, right, upper and lower beams, from which the narrowed resulting beams are formed.

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