RU2691672C1 - Receiving multiplicative paa - Google Patents

Abstract

FIELD: antenna equipment.

SUBSTANCE: invention relates to antenna engineering and can be used in communication and radar systems. Receiving multiplicative phased antenna array (PAA) consisting of antenna arrays, from the outputs of which signals are transmitted to the inputs of the multiplication system, is characterized by the fact that the PAA elements by random sampling are divided into equal parts by the number of arrays, wherein each array is sparse with random distribution of elements along the PAA aperture. All the arrays form a two-dimensional PAA of a given shape (rectangular, round, elliptical, etc.). Elements of the arrays fill the area of the aperture of the phased antenna array completely (without passing the grid nodes). As a result, the maximum level of side lobes of the multiplicative directivity pattern will be approximately equal to (-13.26 dB)L, where L is the number of sub-arrays forming a multiplicative PAA.

EFFECT: high gain of the antenna array at low level of side lobes (LSL) of the directional pattern (DP).

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Description

The technical field to which the invention relates.

The invention of a phased array antenna (PAR) refers to antenna technology and can be used in radar and communication systems.

The level of technology

The known devices are the Drain's correlation lattice and antennas with multiple correlation operations [1].

As a prototype, an antenna was chosen, designed to achieve maximum resolution with a small number of elements [1, 2]. The prototype consists of two mutually perpendicular transversely radiating linear antenna arrays with a uniform distribution of elements. The number of elements of one array is N, the second array is M. The signals received when each linear antenna is received are multiplied (antennas with signal multiplication are also called multiplicative antennas [3]). As a result, if the radiation patterns of both gratings F ₁ (Θ, ϕ) and F ₂ (Θ, ϕ), where Θ is the meridional angle (elevation angle), ϕ is the azimuth angle, then after multiplication the output signal is proportional to F ₁ (Θ, ϕ) × F ₂ (Θ, ϕ), which corresponds to a signal from a flat two-dimensional lattice consisting of N × M elements, the sides of which are equal to the lengths of linear uniform mutually perpendicular lattices.

The disadvantages of this device are:

- small compared to a flat two-dimensional lattice gain, since the directional coefficient of the lattice is proportional to the number of elements;

- a high level of side lobes of the DN, which with the same gain of all the elements of the lattice can not be below -13.26 dB, which does not allow the use of these antennas in radar systems. The reduction of the side lobes of the DN due to the creation of the amplitude distribution falling to the edges further reduces the directional coefficient (KND) of the antenna system.

DISCLOSURE OF INVENTION

The technical result of the invention is to obtain a high gain antenna array with a low level of side lobes (UBL) radiation pattern (NAM).

The technical result is achieved by the fact that, unlike the prototype in which, the elements of antenna arrays are evenly distributed, and the signals from the outputs of the arrays are fed to the inputs of the multiplication system, in the present invention, the PAR elements are randomly divided into equal parts by the number of arrays, the lattice is sparse with a random distribution of elements around the aperture of the PAR

The elements of each of the grids are arranged on a flat surface in the nodes of a regular grid (square, rectangular or triangular) in a random way. The gratings form a two-dimensional HEADLIGHT of a given shape (rectangular, circular, elliptical, etc.), and the grating elements fill the area of the HEADING aperture completely (without missing grid nodes). The number of grids is selected taking into account the required level of side lobes and the minimum allowable signal-to-noise ratio at the grid output.

соответственно. Все расчеты производились для рабочей частоты 3000 МГц для изотропных приемных элементов.FIG. 1 shows the position of the centers of the elements of a rectangular HEADLIGHT consisting of 30 × 20 elements divided into 3 lattices, the signals from the output of which are multiplied. The position of the centers of the elements of each lattice is indicated by the symbols:

respectively. All calculations were made for an operating frequency of 3000 MHz for isotropic receiving elements.

FIG. 2 (a, b, c) the dashed lines show the bottoms of each lattice in the azimuthal plane; in FIG. 4 (a, b, c) - in the elevation plane. For a direction with a zero angle, the direction of the perpendicular to the center of the HEADLIGHTS is taken. For comparison, in all figures the solid line shows the DN of the entire HEADLAMP when adding signals from the arrays (DN additive HEADLAMP). It is known that for a rarefied HEADLIGHT the width of the main lobe of the DN depends on the total size of the aperture [4], as a result it almost coincides with the width of the main lobe of the DN of each lattice. The average UBL for a rarefied lattice increases, while the maximum UBL can be either larger or smaller than the maximum UBL for the additive HEADLAMP and depends on the position of the elements in the rarefied lattice. The results of the NAM calculations are shown in graphs (Fig. 2, Fig. 4). Calculations of DNs confirmed that for a multiplicative rectangular headlight with equal amplitude distribution consisting of L arrays whose signals are multiplied, the maximum LLL approaches the level (-13.26 dB) L. FIG. 3 and FIG. 5, the calculated DN of the multiplicative PAR in the azimuthal and elevation planes, respectively, are presented, respectively, and FIG. 6 biaxial DN of this multiplicative PAR.

Description of the drawings

FIG. 1 shows the position of the centers of elements of a rectangular HEADLIGHT consisting of 30 × 20 elements divided into three grids, the signals from the outputs of which are multiplied. Each lattice consists of 200 elements arranged randomly along the nodes of a regular rectangular grid.

FIG. 2 (a, b, c), the dotted line shows the normalized DNs of three lattices of which the multiplicative PAR in the azimuthal plane consists, the solid line is the DN of the ordinary (additive PAR) with the same geometry. Calculations are made for a frequency of 3000 MHz.

FIG. 3 shows the DN of the considered multiplicative PAR (dotted line) and, for comparison, the DN of additive PAR with the same geometry (solid line) in the azimuth plane.

FIG. 4 (a, b, c) the dotted line shows the normalized DNs of three lattices of which the multiplicative PAR in the azimuthal plane consists, the solid line is the DN of the ordinary (additive PAR) with the same geometry.

FIG. 5 shows the DNs of the considered multiplicative PAR (dashed line) and, for comparison, the DN additive PAR, with the same geometry (solid line) in the elevation plane.

FIG. 6. The two-coordinate DN of the multiplicative HEADLIGHT shown in FIG. one.

The implementation of the invention

The device works as follows.

Signals are received and amplified by arrays, the elements of which are randomly distributed around the aperture of the HEADLIGHT. Depending on the operating frequency, signal bandwidth requirements, gain and mass-dimensional characteristics, various types of antennas can be used as grating elements (dipoles, log-periodic antennas, open waveguide ends, waveguide horn antennas, etc.). The signals from the outputs of the gratings are fed to the inputs of the multiplication system. Multiplication of signals can be done both in digital form, after preliminary analog-digital conversion, and in analog form, for example, by summing signals from the outputs of logarithmic amplifiers.

Bibliographic data

1. Benenson L.S. Antenna arrays. M .: Soviet Radio, 1966. p. 307-309.

2. Scanning microwave antenna systems. Per. from English Ed. G.T. Markov and A.F. Chaplin. M. Volume 1. M .: Soviet Radio, 1966. p. 373-376.

3. Reutov A.P., Mikhailov B.A., Kondratenkov G.S., Boyko B.V. Side-looking radar stations. M .: Soviet Radio, 1970. p. 65.

4. Handbook of radar. Ed. M. Skolnik. New York, 1970. Trans. from English K.N. Trofimova. Volume 2. Radar antenna devices. Ed. P.I. Angelica M .: Soviet Radio, 1977. S. 157.

Claims (1)

Receiving multiplicative phased antenna array (PAA) consisting of antenna arrays, from the outputs of which the signals arrive at the inputs of the multiplication system, characterized in that the PAR elements are randomly divided into equal parts according to the number of arrays, each lattice being sparse with a random distribution elements on the aperture PAR.

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