RU2762240C1 - Excitation device of planar overlapping subarrays with contour directional diagrams - Google Patents

Abstract

FIELD: antenna equipment.

SUBSTANCE: invention relates to phased antenna arrays (PAA), and more specifically to planar overlapping subarrays with contour directional diagrams. Essence: the excitation device of planar overlapping subarrays with contour directional diagrams contains a power divider, a signal mixing unit, emitters and directional couplers. The input of the power divider is made with the possibility of connection to the control device. The central output of the power divider is directly connected to the central input of the signal mixing unit. Each of the six peripheral outputs of the power divider is connected to the first input port of the corresponding directional coupler, the first output port of which is connected to the corresponding input of the signal mixing unit, its second input port is connected to the output of the corresponding peripheral output of the neighboring power divider, and the second output port is connected to the corresponding peripheral input of the neighboring signal mixing unit. The coupling coefficients between the cross ports of each of the six specified directional couplers are equal and range from 0.33 to 0.48. The signal mixing unit is designed with the possibility of sending a signal directly from the central input to the central output. The emitters are grouped into seven-element modules, so that one emitter is located in the center of the hexagon, and the other six are at its vertices. The central output of the signal mixing unit is connected to an emitter located in the center of the hexagon, and each of the peripheral outputs of the signal mixing unit is connected to a corresponding emitter located at the vertex of the said hexagon.

EFFECT: formation of a contour directional diagrams with a flat top with an increased aperture efficiency value while maintaining the longitudinal size of the PAA.

1 cl, 12 dwg

Description

The invention relates to phased array antennas (PAR), and more specifically to planar overlapping subarrays with contour radiation patterns.

Known is a device for exciting planar overlapping subarrays containing emitters, power dividers and directional couplers. The operation of the device is based on the use of a cascade connection of linear overlapping subarrays located perpendicular to each other (Skobelev S.P. Phased antenna arrays with sectorial partial radiation patterns. M: Fizmatlit, 2010, Figure 2.11).

The disadvantages of the known emitter is a significant (almost twofold) increase in the longitudinal size of the HEADLIGHTS.

A known device for exciting planar overlapping sublattices contains a power divider, a signal mixing unit, emitters and directional couplers (US patent 9374145, publ. 06.21.2016).

This known emitter is adopted as the closest analogue to the claimed multilayer printed emitter.

The disadvantages of the known emitter are that the formation of contour radiation patterns with flat tops is achieved only at the cost of a certain decrease in the level of the flat top in the directions close to the normal to the plane of the aperture (in particular, in comparison with the analogue) and a decrease in the surface utilization factor (SP) (Skobelev SP Some features of the overlapped subarrays built up of beam-forming matrices for shaping flat-topped radiation patterns. IEEE Transactions on Antennas and Propagation. 2015. V. 63. No. 12. P. 5529-5535).

The technical problem solved by the present invention is the creation of a device for exciting planar overlapping subarrays with contour radiation patterns, devoid of the above disadvantages.

As a result, the technical result is achieved, which consists in the formation of a contour radiation pattern with a flat top with an increased value of the KPI while maintaining the longitudinal size of the HEADLIGHTS.

The specified technical result is achieved by creating a device for exciting planar overlapping subarrays with contour radiation patterns, containing a power divider, a signal mixing unit, emitters and directional couplers. The power divider input is configured to be connected to the control device. The central output of the power divider is directly connected to the central input of the signal mixing unit. Each of the six peripheral outputs of the power divider is connected to the first input port of the corresponding directional coupler, the first output port of which is connected to the corresponding input of the signal mixing unit, its second input port is connected to the output of the corresponding peripheral output of the adjacent power divider, and the second output port is connected to the corresponding peripheral the input of the adjacent signal mixing block. The coupling factors between the cross ports of each of the six specified directional taps are equal and range from 0.33 to 0.48. The signal mixing unit is configured to feed a signal directly from the central input to the central output. The first peripheral input of the signal mixing unit is connected to the first input port of the first directional coupler, the first output port of which is connected to the second input port of the fifth directional coupler, the second output port of which is connected to the first peripheral output of the signal mixing unit. The third peripheral input of the signal mixing unit is connected to the first input port of the third directional coupler, the first output port of which is connected to the second input port of the first directional coupler, the second output port of which is connected to the third peripheral output of the signal mixing unit. The fifth peripheral input of the signal mixing unit is connected to the first input port of the fifth directional coupler, the first output port of which is connected to the second input port of the third directional coupler, the second output port of which is connected to the fifth peripheral output of the signal mixing unit. The second peripheral input of the signal mixing unit is connected to the first input port of the second directional coupler, the first output port of which is connected to the second input port of the sixth directional coupler, the second output port of which is connected to the second peripheral output of the signal mixing unit. The fourth peripheral input of the signal mixing unit is connected to the first input port of the fourth directional coupler, the first output port of which is connected to the second input port of the second directional coupler, the second output port of which is connected to the fourth peripheral output of the signal mixing unit. The sixth peripheral input of the signal mixing unit is connected to the first input port of the sixth directional coupler, the first output port of which is connected to the second input port of the fourth directional coupler, the second output port of which is connected to the sixth peripheral output of the signal mixing unit. The coupling factors between the cross ports of the first, second, third, fourth, fifth, and sixth directional taps are equal and range from 0.33 to 0.48. The emitters are grouped into seven-element modules, in such a way that one emitter is located in the center of the hexagon, and six others are at its vertices. The central output of the signal mixing unit is connected to a radiator located in the center of the hexagon, and each of the peripheral outputs of the signal mixing unit is connected to a corresponding radiator located at the vertex of said hexagon.

The figure 1 shows a General view of the device for exciting planar overlapping subarrays with contour radiation patterns.

Figure 2a shows a schematic arrangement of directional couplers connecting adjacent subarrays.

Figure 2b shows a diagram of a directional coupler.

Figures 3a and 3b show a block diagram of a signal mixing unit.

Figures 4a and 4b show a schematic arrangement of emitters in a planar array according to particular versions.

Figure 5 shows the amplitude distribution of the excitation signals over the emitters in the sub-array.

Figure 6 shows a contour map of the levels of the normalized sublattice factor in the absence of connections between the sublattices.

Figure 7 shows a contour map of the levels of the normalized sublattice factor corresponding to the presence of connections between the modules at q ₁ = 0.45 and q = 0.36.

Figure 8 shows the dependence of the normalized multiplier of the sublattice in the horizontal and vertical planes for the prototype and the claimed invention.

Figure 9 shows the dependence of the normalized sublattice factor in the horizontal and vertical planes in the absence and presence of connections between the sublattices.

The device for exciting planar overlapping subarrays with contour radiation patterns, shown in Figures 1-4, contains a power divider 1, a signal mixing unit 2, emitters 3a, 3b, 3c, 3d, 3e, 3f, 3g and directional couplers 4a, 4b, 4c, 4d, 4f, 4f.

The input 5 of the power divider 1 is configured to be connected to a control device (not shown in the figures). The control device provides a signal with a certain amplitude and phase to the input 5.

The central output 1g of the power divider 1 is directly connected to the central input (not shown in the figures) of the signal mixing unit 2.

Each of the six peripheral outputs 1a-1f of the power divider 1 is connected to the first input port of the corresponding directional coupler (in particular, 1a to 4a ₁ , the rest are not shown in the figures so as not to overload them), the first output port of which is connected to the corresponding input of the mixing unit signals (in particular, 4a ₁ , c 2a, the rest are not shown in the figures so as not to overload them). The second input port of each of the mentioned directional couplers is connected to the corresponding peripheral output of the adjacent power divider (adjacent (related to adjacent subarrays) power dividers 6, 7, 8, 9, 10, 11). In particular, the second input port 4a _{2 of the} directional coupler 4a is connected to the output 8d of the adjacent power divider 8, the remaining positions are not shown in the figures so as not to overload them. The second output port is connected to the corresponding peripheral input of the adjacent signal mixing unit (the inputs of the adjacent signal mixing units are not shown in the figures so as not to overload them). The coupling coefficients between the cross ports (in particular 4a ₁ and 4a _{2 '} , 4a ₂ and 4a _1' ) of the six indicated directional couplers 4a, 4b, 4c, 4d, 4e, 4f are equal to each other and are in the range from 0.33 to 0.48.

The selection of pairs of the peripheral output of the power divider 1 of the peripheral output of the adjacent power divider, between which the directional couplers are installed, is performed as follows. The peripheral output of the power divider 1 is taken (for example 1a), the same outputs are determined on the adjacent power dividers (see Fig. 2, the same peripheral outputs are designated as 6a, 7a, 8a, 9a, 10a, 11a). These outputs are used to determine diametrically opposite (located symmetrically relative to the central output) outputs (6d, 7d, 8d, 9d, 10d, 11d). Of these, the nearest output is selected (for peripheral output 1a, this closest output will be 8 g). The result of this choice is shown in FIG. 2a.

The signal mixing unit 2, shown in figures 3a and 3b, is configured to supply a signal directly from the central entrance to the central output using a transmission line (not indicated in the figures).

The signal mixing unit 2 includes the first 18, the second 19, the third 20, the fourth 21, the fifth 22 and the sixth 23 directional couplers.

The first peripheral input 2a of the signal mixing unit 2 is connected to the first input port 18 _{1 of the} first directional coupler 18, the first output port 18 ₁ 'of which is connected to the second input port 22 _{2 of the} fifth directional coupler 22, the second output port 22 _{1' of} which is connected to the first peripheral output 2a 'of the signal mixing unit 2. The third peripheral input 2 from the signal mixing unit is connected to the first input port 20 _{1 of the} third directional coupler 20, the first output port 20 _{1' of} which is connected to the second input port 18 _{2 of the} first directional coupler 18, the second output port 18 _{2 'of} which is connected to the third peripheral output 2c' of the signal mixing unit 2. The fifth peripheral input 2e of the signal mixing unit 2 is connected to the first input port 22 _{1 of the} fifth directional coupler 22, the first output port 22 _{1 'of} which is connected to the second input port 20 ₂ third directional coupler 20, the second output port 20 _{2 '} which is connected to the fifth periphery by the line output 2e 'of the signal mixing unit 2.

The second peripheral input 2b of the signal mixing unit 2 is connected to the first input port 19 _{1 of the} second directional coupler 19, the first output port 19 _{1 'of} which is connected to the second input port 23 _{2 of the} sixth directional coupler 23, the second output port 23 _{2' of} which is connected to the second peripheral the output 2b 'of the signal mixing unit 2. The fourth peripheral input 2d of the signal mixing unit 2 is connected to the first input port 21 _{1 of the} fourth directional coupler 21, the first output port 21 _{1' of} which is connected to the second input port 19 _{2 of the} second directional coupler 19, the second output port 19 _{2 '} which is connected to the fourth peripheral output 2d' of the signal mixing unit 2. The sixth peripheral input 2f of the signal mixing unit 2 is connected to the first input port 23 _{1 of the} sixth directional coupler 23, the first output port 23 _{1 'of} which is connected to the second input port 21 ₂ fourth directional coupler 21, the second output port 21 _{2 '} which is connected to the sixth peripheral output 2f of the signal mixing unit 2.

Coupling ratio between cross ports (18 ₁ and 18 _{2 '} , 18 ₂ and 18 _1' , 19 ₁ and 19 _{2 '} , 19 ₂ and 19 _1' , etc.) of the first 18, the second 19, the third 20, the fourth 21 The fifth 22 and sixth 23 directional couplers are equal and range from 0.33 to 0.48.

Emitters 3a-3g are grouped into seven-element modules, so that one emitter (3g) is located in the center of the hexagon, and six others are at its vertices. The central output of the signal mixing unit 2 is connected to an emitter 3g located in the center of the hexagon, and each of the peripheral outputs of the signal mixing unit is connected to a corresponding emitter located at the apex of the said hexagon (2a 'with 3a, 2b' with 3b, 2c 'with 3c, 2d 'with 3d, 2e' with 3e and 2f 'with 3f).

The claimed device for exciting planar overlapping subarrays with contour radiation patterns operates as follows.

A signal of the required amplitude and phase is supplied to the input 5 of the power divider 1 from the control device. Specific values of the amplitude and phase are selected based on obtaining the required radiation pattern created by the entire phased array antenna, which includes the sub-array.

The power divider divides the input signal into seven equal parts fed to the center output 1g and the peripheral outputs 1a-1f of the power divider 1.

The signal from the central output of the power divider 1g using a signal transmission line is fed through the signal mixing unit 2 (where it is not mixed with other signals) to the central emitter 3g.

The signal from each of the peripheral outputs 1a-1f using the signal transmission line is first fed to the input port of the directional coupler (4a-4f, respectively), where it is mixed with the signal coming from the corresponding output of the adjacent power divider, and then to the corresponding input (2a-2f ) of the signal mixing unit 2.

Figure 2b shows a diagram of a directional coupler, where q _{1 is the} coupling coefficient between the cross ports and p ₁ = (1-q ₁ ² ) ^1/2 . When a signal with an amplitude of 1 is applied to one of the input ports, we will have a signal iq ₁ at the cross output port (the signal phase is shifted relative to the signal at the input port by 90 degrees), and at the direct output port we will have a signal p ₁ = (1-q ₁ ² ) ^1/2 (hereinafter p ₁ and q ₁ refer to directional couplers 4a-4a, and p and q refer to directional couplers 18, 19, 20, 21, 22, 23).

In the signal mixing unit 2, the signals arriving at the peripheral inputs 2a, 2c and 2e are mixed with each other using three directional couplers 18, 20 and 22. And the signals arriving at the peripheral inputs 2b, 2d and 2f are mixed with each other using three directional couplers 19, 21 and 23. After that, the signals from the peripheral outputs 2a'-2f 'are fed to the emitters 3a-3f.

Let us determine the coupling coefficients between the inputs 2a-2f and the outputs of the mixing unit 2. Let the signal of unit amplitude arrive at the input 2a of the signal mixing unit (see Fig. 3b) and then to the input port 18 _{1 of the} first directional coupler 18. As a result of the signal passing through the couplers 18, 20, 22, at the inputs 18 ₂ , 20 ₂ and 22 _{2 of the} couplers 18, 20 and 22, respectively, there will be signals with amplitudes B ₁ , B ₂ and B ₃ (also indicated in Fig. 3b). Using the transmission matrix of directional couplers (see Fig.2b), we can determine that the indicated amplitudes are related to each other and to the unit amplitude of the signal arriving at the input 2a by the relations B ₁ = p + iqB ₂ , B ₂ = iqB ₃ , B ₃ = iqB ₁ , where q is the coupling factor between the cross ports and p = (1-q ² ) ^1/2 . The presented ratios do not take into account the same multiplier for them, which corresponds to the passage of the signal along the transmission lines connecting adjacent taps (but this factor is not important for further calculation). Expressing B ₁ , B ₂ and B ₃ , we get:

Using again the parameters of the couplers 18, 20, 22 and the found amplitudes B ₁ , B ₂ and B ₃ , we obtain the amplitudes of the signals received at the peripheral outputs 2a ', 2c' and 2e 'of the mixing unit 2:

Note that if signals of unit amplitude are applied to all three peripheral inputs 2a, 2c and 2e simultaneously, then the signal amplitudes at the peripheral outputs 2a ', 2c' and 2e 'will be the same and equal to the sum of amplitudes C ₁ + C ₂ + C ₃ :

Similar expressions are obtained for another triple of connected inputs 2b, 2d and 2f of mixing unit 2.

The obtained coupling coefficients between the peripheral inputs 2a, 2b, 2c, 2d, 2e, 2f and the peripheral outputs 2a ', 2b', 2c ', 2d', 2e 'and 2f', make it possible to calculate the amplitude distribution of signals over the emitters 3a-3g of the sublattice and sublattice multiplier.

Let us assume that the amplitudes of the signals at the six peripheral outputs 1a-1f of the power divider 1 are equal to unity. These signals then pass through directional couplers 4a-4f, block 3 containing directional couplers 18-23, and enter the radiators 3a-3f. As a result, a symmetric amplitude distribution, shown in FIG. 5, where the empty circles correspond to unexcited emitters.

Amplitudes A ₁ correspond to signals transmitted between the direct ports of directional couplers 4a-4f (4a ₁ -4a _{1 '} , 4b ₁ -4b _1' , etc.), and uniform excitation of the inputs of the signal mixing unit 2 (provided by the equality of the coupling coefficients between crossover ports of directional couplers 4a-4f.

The amplitudes A ₂ correspond to the passage of signals between the cross ports of directional couplers 4 (4a ₁ -4a _{2 '} , 4b ₁ -4b _2' , etc.), as well as the passage

through the adjacent side of mixing signals (12, 13, 14, 15, 16, 17) along a path similar to the path 2a-2a 'in the signal mixing unit 2 (see Fig.3b):

The amplitudes A ₃ , and A ₄ also correspond to the passage of signals between the cross inputs of the couplers 4 (4a ₁ -4a _{2 '} , 4b ₁ -4b _2' , etc.), as well as the passage through the adjacent mixing side of signals (12, 13, 14, 15, 16, 17) by way similar paths 2a-2c (for the amplitude a ₃₎ and 2a-2e '(for the amplitude a ₄₎ mixing signals in the block 2 (see Figure 3b)..:

The complex amplitude A _{0 of the} signal in the central radiator 3g of the sublattice is determined only by the power divider 1 and the length of the transmission line from the central output lg of the power divider 1 to the central radiator 3g. This amplitude is determined by the following considerations. If all the inputs of the power divider of the array (which consists of sublattices) are excited uniformly, and the amplitudes of the signals at all peripheral outputs of the power dividers are equal to unity, then all inputs of the signal mixer blocks will be excited uniformly by signals with the amplitude p ₁ + iq ₁ . Consequently, the signal amplitudes at the outputs of the signal mixing units and at the inputs of the emitters connected to them will be determined by the formula

where

Ф = arctan (q ₁ / p ₁ ) + arctanq.

, модуль которой равен единице. Отсюда следует то требование к делителю мощности 1, что он должен обеспечивать равномерное деление входного сигнала на все семь его выходов 1а-11g. Необходимая фаза сигнала, поступающего на центральные излучатели каждого модуля, должна быть согласована с фазой Ф=arctan(q₁/p₁)+arctanq либо путем подбора длины передающей линии от центрального выхода 1g делителя мощности 1 до излучателя 3g, либо установкой фиксированного фазовращателя в указанной линии.The natural choice, corresponding to ensuring a uniform amplitude distribution of signals over all radiators of the array, including the central ones, corresponds to the fact that A ₀ should be equal to the amplitude

, the modulus of which is equal to one. Hence follows the requirement for the power divider 1, that it must ensure uniform division of the input signal into all seven of its outputs 1a-11g. The required phase of the signal arriving at the central radiators of each module must be matched to the phase Ф = arctan (q ₁ / p ₁ ) + arctanq either by selecting the length of the transmission line from the central output 1g of the power divider 1 to the radiator 3g, or by installing a fixed phase shifter in the specified line.

Having determined the amplitude distribution of signals over the emitters of the sublattice, shown (Fig. 5), it is easy to calculate the subarray factor determined by the formula

where U = kau, V = kbν, k = 2π / λ is the wavenumber, u = sinθcosϕ ν = sinθsinϕ are the direction cosines of the observation point, characterized by the angle θ, measured from the normal to the aperture, and the angle ϕ, measured from the x axis.

что соответствует гексагональной сетке расположения излучателей (см. фиг. 4а). В случае отсутствия связи между подрешетками, реализуемом при q₁=0, возбуждаются излучатели только центрального модуля сигналами одинаковой амплитуды. Карта уровней нормированного множителя подрешетки |f(u,ν)|/7, соответствующая указанному случаю, показана на фиг. 6. Наличие связи между подрешетками (при q₁>0) приводит к образованию перекрывающихся подрешеток. Исследование влияния параметров q₁ и q на форму множителя подрешетки показало, что при 0.33<q, q<0.48, 0.33<q₁, q₁<0.48 формируется плоская вершина множителя подрешетки, требуемая в оптимальных ФАР, предназначенных для сканирования в узкой угловой области пространства. Пример карты уровней нормированного множителя подрешетки с такой вершиной, полученной при q₁=0.45 и q=0.36, показан на фиг. 7. Сравнивая результаты на фигурах 6 и 7, видно, что область, ограниченная, например, линией уровня 0.9, оказывается заметно шире для случая ФАР с перекрывающимися подрешетками.The results of calculating the modulus of the sublattice factor f (u, ν), normalized to its maximum equal to 7, presented in Fig. 6a, for a lattice with a = 0.7λ and

which corresponds to the hexagonal grid of the location of the emitters (see Fig. 4a). In the absence of communication between the sublattices, which is realized at q ₁ = 0, only the emitters of the central module are excited by signals of the same amplitude. The level map of the normalized factor of the sublattice | f (u, ν) | / 7 corresponding to this case is shown in Fig. 6. The presence of a bond between the sublattices (for q ₁ > 0) leads to the formation of overlapping sublattices. The study of the influence of the parameters q ₁ and q on the shape of the sublattice factor showed that at 0.33 <q, q <0.48, 0.33 <q ₁ , q ₁ <0.48, a flat top of the sublattice factor is formed, which is required in optimal PARs intended for scanning in a narrow angular region space. An example of a level map of the normalized sublattice factor with such a vertex, obtained for q ₁ = 0.45 and q = 0.36, is shown in Fig. 7. Comparing the results in Figures 6 and 7, it can be seen that the region bounded, for example, by the line of the 0.9 level, turns out to be noticeably wider for the case of PAR with overlapping sublattices.

Sections of the modulus of the sublattice factor corresponding to the horizontal and vertical planes for the prototype and the claimed invention (at q ₁ = 0.45 and q = 0.36) are shown in Fig. eight.

The sections of the modulus of the sublattice multiplier corresponding to the considered cases of overlapping and non-overlapping sublattices in the vertical and horizontal planes are shown in Fig. 9.

Comparison of the results obtained here with the sublattice multiplier corresponding to the application of the prototype scheme for the interelement distances indicated above shows that the proposed scheme provides 100% efficiency of the aperture in the normal direction (and, consequently, the maximum EIA) and thus a higher level of the sublattice multiplier compared to the prototype.

Claims (1)

An excitation device for planar overlapping subarrays with contour radiation patterns, containing a power divider, a signal mixing unit, emitters and directional couplers, while the power divider input is capable of being connected to a control device, the central output of the power divider is directly connected to the central input of the signal mixing unit, each of the six peripheral outputs of the power divider is connected to the first input port of the corresponding directional coupler, the first output port of which is connected to the corresponding input of the signal mixing unit, the second input port is connected to the output of the corresponding peripheral output of the adjacent power divider, and the second output port to the corresponding peripheral input of the adjacent signal mixing unit, and the coupling coefficients between the cross ports of each of the six indicated directional couplers are equal and are in the range from 0.33 to 0.48, the signal mixing unit is made with the ability to supply a signal directly from the central input to the central output, the first peripheral input of the signal mixing unit is connected to the first input port of the first directional coupler, the first output port of which is connected to the second input port of the fifth directional coupler, the second output port of which is connected to the first peripheral output of the mixing unit signals, the third peripheral input of the signal mixing unit is connected to the first input port of the third directional coupler, the first output port of which is connected to the second input port of the first directional coupler, the second output port of which is connected to the third peripheral output of the signal mixing unit, the fifth peripheral input of the signal mixing unit is connected with the first input port of the fifth directional coupler, the first output port of which is connected to the second input port of the third directional coupler, the second output port of which is connected to the fifth peripheral output of the mixing unit signals, the second peripheral input of the signal mixing unit is connected to the first input port of the second directional coupler, the first output port of which is connected to the second input port of the sixth directional coupler, the second output port of which is connected to the second peripheral output of the signal mixing unit, the fourth peripheral input of the signal mixing unit is connected with the first input port of the fourth directional coupler, the first output port of which is connected to the second input port of the second directional coupler, the second output port of which is connected to the fourth peripheral output of the signal mixing unit, the sixth peripheral input of the signal mixing unit is connected to the first input port of the sixth directional coupler, the first the output port of which is connected to the second input port of the fourth directional coupler, the second output port of which is connected to the sixth peripheral output of the signal mixing unit, and the coupling coefficient between the crossover the mouths of the first, second, third, fourth, fifth and sixth directional couplers are equal and are in the range from 0.33 to 0.48, the emitters are grouped into seven-element modules, so that one emitter is located in the center of the hexagon, and six others are at its vertices, when the central output of the signal mixing unit is connected to a radiator located in the center of the hexagon, and each of the peripheral outputs of the signal mixing unit is connected to a corresponding radiator located at the vertex of said hexagon.

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