RU2093936C1 - Wire-range circular antenna array - Google Patents

Abstract

FIELD: electrical engineering. SUBSTANCE: antenna array has at least one planar dielectric base with metallized layers incorporating excitation system and radiating aperture coupled with it and formed from horn radiators arranged in several levels; radiating aperture of antenna array forms closed second-order curve such as circumference; its metallized layers incorporating radiating aperture are arranged outside around dielectric base carrying excitation system and are connected at points of level discontinuities. If more than one antenna array is installed, they form volumetric assembly of intercoupled antenna arrays. EFFECT: enlarged scanning sector of space amounting to 360 deg and reduced loss in adding system. 3 cl, 4 dwg

Description

 The present invention relates to the field of electrical engineering and can be used as a wide-range omnidirectional antenna in the horizontal plane, where biconical horns and discus antennas are known.

 These antenna systems (AS) are effective devices that allow obtaining acceptable technical parameters [1] But the lack of a developed theoretical base for constructing such antennas makes them expensive, the resulting technical parameters are not optimal, and the overall dimensions are large, often unacceptable for widespread use (use) .

 Currently, the need for speakers with circular radiation patterns (ND) is very high, especially for television (television centers (towers, towers)) and cellular communication systems.

 A technical solution is known [2] where a broadband linear antenna array (LAR) is proposed that contains a flat dielectric base with metallized layers in which an excitation system and radiating aperture are made.

The disadvantages of this device are:
limited sector of the review of space, determined by the width of the day;
the presence of losses associated with the asymmetry of the excitation system (summation).

The tasks to be solved by the claimed invention is directed:
expanding the sector of the review of space 360 ^o ;
reduction of losses in the excitation system (summation).

 In accordance with the invention, the tasks are solved by means of a wide-band circular AR, which contains at least one flat dielectric base with metallized layers, in which the excitation system and associated radiating aperture, formed from horn radiators placed at several levels, the radiating aperture, are made AS forms a closed second-order curve, for example, a circle, and the metallized layers of the AR, in which emitting openings are made, are located outside, the coverage vayut dielectric substrate with excitation system and connected to the ground level location of inhomogeneities. If the AR is more than one, then they form a three-dimensional system of "n" paired parallel to each other lattices (n 2, 3).

 The present invention meets the criterion of "novelty", as from publicly available sources of information do not know the technical solution, characterized by a combination of the above features of the invention.

 The present invention meets the criterion of "inventive step", since due to such a design of the AR that implements dynamic AFR at the aperture, it is possible to solve the problems of obtaining a circular radiation pattern, expanding the bandwidth, matching the CAR with free space.

 Figure 1 shows a wide-range flat circular antenna array (CAR); FIG. 2 illustrates the “mechanism” of re-reflection of natural waves on inhomogeneities; FIG. 3 the principle of mode superposition for the case of in-phase excitation of an inhomogeneity; figure 4 shows the appearance of the CAR.

Figure 1 marked:
1 zero-level radiator (flat horn), 2 first-level radiator (communication region M ₁ ), 3 external walls (forming) of the first-level radiator, 4 internal (adjacent) walls (forming) of the zero-level radiator, 5 second-level radiator (communication region M ₂ ), 6 - free space, 7 slotted line, 8 current-carrying strip of the strip line.

In FIG. 4 are indicated:
1 upper metal screen of the strip line with multi-level emitters and slots made on it, 2 lower metal screen of the strip line with multi-level emitters and slots made on it, 3 current-carrying plate of the strip line that implements the excitation system (summed), 4 connection areas of the upper and bottom screens.

In FIG. 1, the shaded part corresponds to the presence of a metal surface, the dotted line indicates the current-carrying metal plate of the strip line, which implements the excitation (summation) system of a circular antenna array (CAR). Radial lines drawn through the center of the circle O and points O ₁ , O ₂ and O ₃ are the axis of symmetry for the emitters of the first, second and third levels, respectively.

In addition, points О ₁ , О _2, and О ₃ characterize the location of inhomogeneities for which boundary conditions can be strictly formulated, since they are located inside the guide systems formed by the proposal of the external (external) walls of the respective emitters or are joined with free space.

 It should be noted that in the general case, the generators of the emitters do not have to be straight lines and are a continuation of the straight line, they can be exponentials, broken lines. For a more precise fixation of the boundary conditions, the generators of neighboring elements at the intersection should be described by a "discontinuous" function, i.e. have a "tip" rather than a smooth curve.

KAR, which realizes a review of space in the plane of the lattice (azimuthal plane) 360 ^o , is a set of emitters of zero level (n ₀ 2 ^p ) with aperture sizes greater than half the wavelength located in pairs one next to the other and deployed in the plane of the lattice at an angle relative to each other, i.e. their openings are located along a curve of the second order, which in a particular case can be a circle. Pairs of neighboring zero-level emitters can be rotated at a different angle, but should always be symmetrical with respect to the radial line drawn through the intersection point of adjacent (adjacent) walls (point O ₁ ) and the center of the circle (point O). For each pair of neighboring zero-level emitters, the external (external) walls (until they intersect each other) are continued to a length of l ₁ , which allows one to create n ₁ 2 ^p-1 emitters of the first level in which the conditions for excitation of propagating modes of both higher and lower ones. Then, for each adjacent pair of emitters of the first level, the outer walls (until they intersect each other) are extended to a length of l ₂ , which makes it possible to obtain n ₂ 2 ^p-2 emitters of the second level. The described process with adjacent pairs of emitters of different levels continues until the curve along which the emitters are located is closed, which means that at the highest "m-level" we have one element (emitter) n _m 2 ^pm = 1 ( the aperture of which is a closed curve (circle)), which has axial (circular) symmetry, forms a circular (omnidirectional) in the plane of the lattice NAM, which provides an overview of the space of 360 ^o in the azimuth plane. P characterizes the number of levels of emitters (for Fig. 1 P 3).

In this case, the CAR has in its composition
the number of elements of the zero level n ₀ 2 ^p
the number of elements of the first level n ₁ 2 ^p-1
the number of elements of the second level n ₂ 2 ^p-2
the number of elements of the highest level "m" n _m 2 ^pm 1.

A feature of constructing the CAR structure is that the emitter of any level (except the zero) is constructed in the same way and contains a “jump-like” junction type heterogeneity that excites a guiding system (M ₁ , M ₂ ), for which the boundary terms. The mechanism of the formation of the field structure in the aperture of an element of any level (except the zero) is exactly the same, but they differ only in boundary conditions. Therefore, the process of obtaining a multi-level aperture taking into account the circular symmetry of the structure can be suspended already at the 2nd or 3rd step, depending on the number of elements of the zero level.

часть пространства слева от стыка

обозначена как область I, плоскость 2 соответствует стыку

пространство справа от стыка

обозначено как область II.In FIG. Figure 2 shows the re-reflections of natural waves between inhomogeneities in the guide system, which, to simplify the figure, are made not in a cylindrical, but in a rectangular coordinate system. For the communication region M _1, plane 1 corresponds to the junction

part of the space to the left of the junction

marked as region I, plane 2 corresponds to the junction

space to the right of the junction

designated as area II.

O₃O₃, а плоскость 2 стыкам O₃O₃; свободное пространство соответственно (см. фиг. 1).For the communication regions M ₂ , M _3, plane 1 corresponds to the joints

O ₃ O ₃ , and the plane 2 to the joints of O ₃ O ₃ ; free space, respectively (see Fig. 1).

A wave E _{0 of} unit amplitude of structure H _{1 is} incident on plane 1 from region I. Part of the energy is reflected back to region I in the form of a wave of the same structure with an amplitude of [N _n ] ₁₁ .

The rest passes to the communication region M in the form of a wave of structure H _p (solid lines) with amplitudes [N _m ] _1p , where p1, 2, 3. K. The number of wave types in region M is not limited.

At plane 2, the waves of the structure H _p acquire an additional phase incursion and have amplitudes P _1p . Each of the waves of the structure H _p on plane 2 is converted into the transmitted wave of region II with an amplitude P _1p R _p1 and reflected waves of the considered types with amplitudes P _1p [M _m ] _pg , where p, g 1, 2, 3. K. Reflected waves again fall on plane 1, partially pass to region I, the rest is reflected, in turn, in the form of a set of taken into account waves.

The considered process of successive reflections allows us to calculate the amplitudes A $\genfrac{}{}{0ex}{}{\text{I}}{\text{m}}$ A $\genfrac{}{}{0ex}{}{\text{II}}{\text{m}}$ and determine the structure of the fields that appeared, respectively, in regions I and II due to multiple re-reflections of waves between inhomogeneities.

и высшие 1'', 2'';

моды. При этом моды 1', 2''и

окажутся в фазе, а 1'', 2'' и

в противофазе. В результате суперпозиции в каждой из областей связи M₃, M₂ останется только результирующая мода (1' + 2');

нечетная, причем мощность, переносимая этой модой, равна сумме мощностей, подаваемых на вход.If plane 1 at the same time decreases some waves H _1, apart considered reflections mechanism between waves H _p of the same structure will be a superposition of given excitation conditions can be distinguished on the hardware either only even or only odd-wave, or receive the set of waves with the desired amplitudes , and due to the selection of the length of the communication region "l" to obtain the required phase incursion. Figure 3 illustrates the superposition mechanism for the case when one even and one odd modes are taken into account in the communication region M (the mechanism of wave re-reflection is not considered). During the in-phase excitation of zero-level emitters by the wave H ₁ , due to the boundary conditions and the conditions for the excitation of the nonuniformity of the jump-like transition, the lower 1 ', 2' propagate in the communication regions M ₁ , M ₂ ;

and higher 1``, 2 '';

fashion. In this case, the mods 1 ', 2''and

will be in phase, and 1 '', 2 '' and

in antiphase. As a result of the superposition, in each of the communication regions M ₃ , M _2, only the resulting mode (1 '+ 2') remains;

odd, and the power transferred by this mode is equal to the sum of the powers supplied to the input.

Since all the emitters of each level in the CAR are identical in construction method, and the excitation scheme of the zero-level emitters is in-phase and equal-amplitude, the steady-state dynamic amplitude-phase distribution (AFR) on the "m" level emitter will also be equally-amplitude and in-phase. And this means that the CAR forms in free space a field similar to a field excited by a common-mode current filament, which propagates in directions perpendicular to the filament (radially). The field has two transverse (with respect to the propagation direction) in-phase components: the electric E _z (E _Φ ) and the magnetic H _Φ (H _z ) (i.e., the KAR excites a TEM wave in free space).

 A wave structure of this type is called a homogeneous cylindrical wave (G. T. Markov et al. Electrodynamics and Radio Wave Propagation. M. Sov. Radio, 1979, pp. 99-103).

Since the KAR excites in free space a homogeneous cylindrical wave, then its MD is almost uniform in the sector of angles 360 ^o in the plane of the lattice.

 On the basis of CAR, very effective (from the point of view of energy) volumetric (cylindrical) ARs in the form of a layered structure combined with an additional vertical adder can be created using known methods for constructing two-dimensional ARs.

 The problem of reducing losses in the CAR is solved by implementing the excitation (summation) scheme on a symmetrical strip line, as shown in FIG. 4. From FIG. 4 also follows that in order to equalize the potential, the upper and lower screens in the region of emitters of all levels should be interconnected. The main advantage of the CAR, in addition to the omnidirectional MD, is its broadband, which is provided by the dynamic AFR at the aperture and by the feature of the excitation of the structure of the TEM wave field in free space. KAP provides a bandwidth of more than two decades.

 From the foregoing, it becomes obvious that the tasks posed in the development of this technical solution have been completely solved by the proposed design of a circular antenna array, which implements dynamic AFR in the aperture, which makes it quite easy to solve the problems of obtaining a circular beam pattern, expanding the bandwidth and matching the CAR with free space.

 The present invention is a very advanced strip antenna, performed using modern technology of printed circuit boards, characterized by compactness, low weight and high adaptability. All this shows that this antenna will find wide application in electrical engineering.

Claims (3)

 1. A wide-band circular antenna array containing at least one flat dielectric base with metallized layers in which the excitation system is made and the radiating aperture associated with it, characterized in that the radiating aperture is made of horn radiators placed at several levels and forms a closed a second-order curve, and the metallized layers of the antenna array, in which the radiating opening is made, are located outside and cover the dielectric base with an excitation system and interconnected.  2. The lattice according to claim 1, characterized in that the radiating opening forms a circle.  3. The array according to claim 1 or 2, characterized in that it introduced additional antenna arrays connected in pairs in parallel by an adder.

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