RU2510970C1 - Broadband turnstile slit antenna - Google Patents

Abstract

FIELD: physics, radio.

SUBSTANCE: invention relates to radio engineering and specifically to broadband antenna systems with horizontal polarisation of the radiation field, having a circular beam pattern in the horizontal plane. The broadband turnstile slit antenna comprises a set of N pairs of conducting plates which, upon connecting N slits, form a set of M upright posts, upper and lower supporting arms which together form an antenna support, as well as a power splitter and feeders.

EFFECT: wider band of matching the antenna with the feeder.

3 cl, 16 dwg

Description

FIELD OF THE INVENTION

The invention relates to radio antennas, in particular to broadband antenna systems with horizontal polarization of the radiation field having a circular radiation pattern in the horizontal plane, a small standing wave coefficient, 1.15 or less, in a wide frequency band. Such antennas are necessary for the transmission and reception of radio signals, television signals, in blind landing systems for aircraft, in radio navigation beacons and other radio systems.

State of the art

The prior art broadband turnstile slit antenna (RF patent No. 2401492 "Broadband turnstile slit antenna", IPC H01Q 13/00, publ. 10.10.2010), selected as a prototype. The specified antenna contains many pairs of conductive plates, each pair of plates is located in one of the N planes, where N≥1, power divider and transmission lines of electromagnetic energy, many M vertical racks with holes, where M≥2, N matching devices, upper and lower brackets, while the set of N planes forms a bunch of planes with a vertical axis; the contour of each plate consists of a rectilinear vertical edge with K ledges, where K≥1, the upper edge, the lower edge and the rectilinear vertical edge, the opposite edge with the ledges; each plate with a vertical edge with ledges aligned with the aforementioned axis of the beam, and the plate is galvanically connected to each other with the formation of ledges K cracks; racks are connected to the upper and lower brackets with the formation of the antenna support; the plates are connected to the antenna support.

However, this antenna has disadvantages. Its matching band with the feeder at the level of the standing wave voltage coefficient (VSWR) below 1.15 is limited to several television channels. Another disadvantage is that the arrangement of the feeders on the plates affects the shape of the antenna pattern and matching.

Disclosure of invention

An object of the present invention is to expand the matching band of the antenna with the feeder, eliminating the dependence of its radiation pattern and matching on the location of the feeders on the plates.

The stated technical problem is achieved in that the antenna system containing many pairs of conductive plates, each pair of plates is located in one of N planes, where N≥1, power divider and transmission lines of electromagnetic energy, many M vertical racks with holes, where M≥2 , N matching devices, upper and lower brackets, wherein a plurality of N planes form a bundle of planes with a vertical axis; the contour of each plate consists of a rectilinear vertical edge with K ledges, where K≥1, the upper edge, the lower edge and the rectilinear vertical edge, the opposite edge with the ledges; each plate with a vertical edge with ledges aligned with the aforementioned axis of the beam, and the plate is galvanically connected to each other with the formation of ledges K cracks; racks are connected to the upper and lower brackets with the formation of the antenna support; the plates are connected to the antenna support, additionally contains N tubular screens, on each plate there are additionally L vertical slots, where L≥1, and P horizontal slots, where P≥0, while each of the N tubular screens is located on one of these N pairs plates with the formation of galvanic contact with the plate at the site of contact of the screen with the plate; one of the ends of the tubular screen is located in close proximity to the edge of the corresponding slit, a part of the screen with the other end is displayed through the hole in the rack outside the plate; each transmission line to N slots is placed inside the corresponding tubular screen, while the outer conductor at the end of each transmission line is galvanically connected to one of the plates in each of the aforementioned plate pairs and to the end of the corresponding tubular screen, and the central conductor is continued into the gap region and is further connected with the Central conductor of the respective matching device, galvanically coupled to a second plate from said pair of plates; transmission lines at their second ends are connected to a power divider.

The introduction of additional tubular shields into the antenna, placing them directly on the plates in the above manner, placing feeders in them, and galvanically connecting the feeders to the ends and edges of the plates made it possible to eliminate the dependence of its radiation pattern and matching on the location of the feeders on the plates. The implementation on the plates of additional slots made it possible to expand the matching band of the antenna with the feeder up to 60%, which in particular allows the simultaneous emission of television signals of any television channels in the decimeter frequency range.

Brief Description of the Drawings

Figure 1 is an exploded perspective view of a wideband slotted turnstile antenna with two pairs of plates in accordance with the present invention.

Figure 2 presents the broadband slotted turnstile antenna in assembled form with two pairs of plates in accordance with the present invention.

Figure 3 is a top view of the assembled antenna shown in figure 2.

Figure 4 presents another embodiment of a broadband slotted turnstile antenna in an unassembled form, in which the third and fourth metal plates are made in the form of one flat plate.

Figure 5 shows another variant of a broadband slotted turnstile antenna, in which the first and fourth, third and second plates are combined in pairs to form direct spatial dihedral angles.

Figure 6 presents another variant of a broadband slotted turnstile antenna, in which the plates are made with a triangular notch.

Figure 7 presents the first prototype turnstile slot antenna.

On Fig shows the Cartesian and spherical coordinate systems.

Figure 9 shows the radiation pattern of a two-sided slot antenna made on the plates 2 and 3 in the plane of the vector E of the first antenna layout.

Figure 10 shows the radiation pattern of a two-sided slot antenna, made on the plates 4 and 5 in the plane of the vector E of the first antenna layout.

Figure 11 shows a diagram of a turnstile slot antenna in the plane of the vector E of the first antenna layout.

On Fig presents a second layout of the antenna.

On Fig shows the calculated (solid line) and experimental (dashed line) radiation patterns of the second antenna sample, made on the plates 2 and 3 in the plane of the vector E of the second antenna layout.

On Fig shows the calculated (solid line) and experimental (dashed line) radiation patterns of the second sample of the antenna, made on the plates 4 and 5 in the plane of the vector E.

On Fig shows the calculated and experimental radiation patterns of the second sample of the turnstile antenna in the plane of the vector E.

On Fig presents the dependence of the VSWR on the frequency for the sample antenna of the present invention.

We now turn to figure 1, which presents a turnstile slot antenna 1 with two pairs of plates in accordance with the present invention. The designations of additional elements begin with the number 101. Antenna 1 contains the first 2, second 3, third 4 and fourth 5 flat conductive plates, four racks 6, 7, 8 and 9, a power divider 10 with input 11 and with first 12 and second 13 outputs , the first 14 and second 15 feeders, the first matching device 16, the second matching device 17, the upper and lower brackets (the brackets are not shown in FIG. 1), the first 101 and second 102 tubular screens, which have galvanic contact with the plates 2, 4, accordingly, on the entire site of their contact with each other. All four plates are the same. Each of the plates 2-5 has a vertical edge 18 with a step 19, an upper edge 20, a lower edge 21, and a straight vertical edge 22. The edge designations are indicated on the fourth plate. Rectangular slots 103 and 104 are made on each of the plates 2-5. The plates 2 and 3 lie in the first plane 23, the plates 4 and 5 lie in the second plane 24, orthogonal to the plane 23. The intersection line of planes 23 and 24 is a vertical straight line 25 .

Plates 2-5 are made of a highly conductive material such as aluminum alloy, copper alloy or steel. Perhaps the use of foil dielectric plates. Racks 6, 7, 8 and 9, the upper and lower brackets can be made of aluminum, brass or steel pipes, channels, corners or other rolled products or a high-frequency dielectric. A standard coaxial cable is used as a feeder. Matching devices 16 and 17 are made in the form of segments of a coaxial cable. The power divider is calculated according to well-known formulas given in textbooks on technical electrodynamics or in manuals on microwave devices. The fairing (not shown in FIG. 1) is made of a high-frequency dielectric.

The above devices are interconnected as follows (figure 2). The first 2, second 3, third 4 and fourth 5 plates are galvanically connected to each other by edges 18 to form straight dihedral angles 26 with a common straight line 25 - the edge of the dihedral angle, hereinafter referred to as the vertical axis 25 of the antenna. In terms of the resulting device has the shape of a cross (Figure 3). The steps 19 on the edges 18 on the first 2 and second 3 plates when the plates are galvanically connected form the first slot 27 with the edges 28 and 29 parallel to the axis 25. The steps 19 on the edges 18 on the third 4 and fourth 5 plates when the plates are galvanically connected form a second gap 30 with edges 31 and 32 parallel to the axis 25. Racks 6, 7, 8 and 9 are made of metal, plates 2-5 are connected to the racks and to the upper and lower brackets with the formation of galvanic contact between the plates and racks, between the plates and the upper and lower brackets. The first tubular screen 101 is in galvanic contact with the first plate 2 in the entire area of their connection. The second tubular screen 102 is in galvanic contact with the third plate 4 in the entire area of their connection.

One of the ends of the tubular screen 101 is located in close proximity to the edge 28 of the slit 27, a part of the tubular screen with the other end is brought out through the hole in the rack 6 outside the plate; a feeder 14 is placed inside the first tubular screen, wherein the outer conductor of the feeder is galvanically connected to the plate 2 and to the said end face of the first tubular screen, and the central conductor is continued into the region of the slit 27 and then connected to the central conductor of the matching device 16, galvanically connected to the plate 3; the feeder with its second end is connected to the output 12 of the power divider 10.

One of the ends of the tubular screen 102 is located in close proximity to the edge 31 of the slit 30, a part of the tubular screen with the other end is brought out through the hole in the rack 8 outside the plate; the feeder 15 is placed inside the second tubular screen, while the outer conductor of the feeder is galvanically connected to the plate 4 and to the said end face of the second tubular screen, and the central conductor is continued into the region of the slit 30 and then connected to the Central conductor of the matching device 17, galvanically connected to the plate 5; the feeder with its second end is connected to a power divider 10.

The lengths of the first 14 and second 15 feeders are equal to each other. Racks 6-9 are attached to the upper and lower brackets to stiffen the antenna structure. The bottom bracket has holes for attaching the antenna to the mast or tower. In this case, the upper and lower brackets are made in the form of a cross, disk or other shape.

In another embodiment, the connections of the struts 6-9 are connected to the upper and lower brackets, the plates have galvanic contact with the upper and lower brackets, and a gap is formed between the plates and racks. In another embodiment, the connections of the plate are connected to the racks with the formation of galvanic contact, the racks are connected to the upper and lower brackets, while gaps are formed between the plates and the upper and lower brackets.

In another embodiment of the antenna 1 (Fig. 4), the third 4 and fourth 5 plates are made together in the form of one plate 41, in which said slit 30, slots 103 and 104 are made.

In another embodiment of the antenna 1 (Fig. 5), the first and fourth plates are made together in the form of a dihedral plate 42, and the second and third plates are made in the form of a dihedral plate 43. In the dihedral plates 42 and 43, holes 44 and 45 are made, which are galvanically connected plates 42 and 43 with each other form the above-mentioned slots 27 and 30.

Preferably, the plates 2-5 are in the shape of a rectangle. However, plates of a different configuration are possible. Figure 6 shows an example of the implementation of antennas with plates 2-5 with a triangular notch. Such configurations of plates 2-5 are possible that when they are connected, plates with a shape called a "bat wing" are formed.

The antenna operates in transmission mode as follows. The power of the generator supplied to the input 11 (figure 3) of the power divider 10 is divided into two equal parts. In this case, the signals at the outputs 12 and 13 of the divider are equal to each other in amplitude and phase shifted by 90 degrees. The slot 27 is excited by a segment of the central conductor 34 of the feeder 14 located in the region between the edges 28 and 29. The slot 30 is excited by a segment of the central conductor 38 of the feeder 15 located in the region between the edges 31 and 32.

The slot antenna, implemented by the first 2, second 3 plates and slot 27, forms in the plane orthogonal to the axis 25, the first radiation pattern in the form of a "figure eight". In this case, the maxima of the radiation pattern are directed perpendicular to the plane 23, in which the first 2 and second 3 plates are located.

The slot antenna, implemented by the third 4, fourth 5 plates and slit 30, forms in the plane orthogonal to the axis 25 a second radiation pattern in the form of a figure-eight. In this case, the maxima of the radiation pattern are directed perpendicularly to the plane 24, in which the third 4 and fourth plates 5 are located. As a result, in the graphic image, the "eights" displaying the aforementioned first and second radiation patterns are rotated 90 ° in the horizontal plane relative to each other. The signals emitted by the first and second slot antennas are phase shifted by 90 ° in space. As a result of the addition in space of the signals emitted by the first and second slot antennas, a circular pattern is formed.

The first prototype turnstile slot antenna

The first prototype turnstile antenna was made (Fig.7). In describing this and subsequent antenna samples, we refer to the digital designations of Figs. 1-4. The first layout 1 consists of the first 2, second 3, third 4 and fourth 5 plates, a power divider 10 in two directions, the first 14 and second 15 feeders. Plates 2-5 are made of tinned sheet 0.3 mm thick. The layout is made as follows. Two copies of a plate 400 × 210 mm ² in size were made. A slit with dimensions of 275 × 20 mm ^{2 was} cut in the center of each plate parallel to the side 400 mm long. The first copy of the plate is used in the sample as the third 4 and fourth 5 plates with a second slot 30. To make the first 2 and second 3 plates, the second copy of the manufactured plate was cut in a straight line coinciding with the axis of the slot. The resulting two plates 2 and 3 are soldered to the first copy of the plate with the formation of the first slit 27. As a result, a device having a plan view of a cross is obtained. The dihedral angles formed by the plates are each 90 °. To the first plate, near the edge 28 of the slot 27, the braid of the first feeder 14, the coaxial cable RK-50-2-21, is soldered. The cable is laid directly on the plate. In the area immediately behind the edge 28, the sheath and the outer conductor of the cable are removed, the central conductor 34 of the coaxial cable 14 is extended into the region of the slit 27 and soldered to the edge 29 of the slit 27 on the second plate 3. The distance from the place of soldering the cable to the narrow (lower) edge of the slit is 55 mm To the third plate 4 in the vicinity of the edge 31 of the slit 30, the braid of the second feeder 15 — the RK-50-2-21 coaxial cable — is soldered. In the area immediately behind the edge 31, the sheath and the outer cable conductor are removed, the central cable conductor 28 is extended to the area of the slot 9 and soldered to the edge of the slot 32 on the fourth plate 5. The desoldering places of the first 14 and second 15 feeders to the plates are spaced on opposite sides from the center of the slots . If we count the distance from the narrow (lower) edge of the first slot to the soldering point of the second feeder, then this distance is 220 mm. The first 14 and second 15 feeders, which are used radio frequency cable RK-50-2-21, have an equal length. As a power divider 10 in two directions, a 3 dB quadrature directional coupler on coupled strip lines is used, which, as you know, provides for dividing the power into two equal parts and a 90 ° phase shift between the output signals.

On Fig presents a spherical coordinate system.

Figure 9 shows the normalized experimental and calculated radiation patterns of a two-sided slot antenna made on plates 2 and 3 in the plane of the vector E. Figure 10 shows the normalized experimental and calculated radiation patterns of a two-sided slot antenna made on plates 4 and 5 in the plane of the vector E. Figure 10 shows the normalized experimental and calculated radiation patterns of the first prototype turnstile antenna in the plane of the vector E. The normalization of the diagram is relative to the average the squared signal level in the plane of the vector E.

The calculated radiation patterns are found by solving the electrodynamic problem using the direct time method. The boundary value problems formulated for a continuous continuum are reduced to variational and projection-grid models. The experimental radiation patterns were measured in the far zone using the “tower method”.

The experimental and calculated radiation patterns of two-sided slot antennas have a symmetrical two-leaf appearance (eights). The maximums of the lobes in the experimental radiation pattern of a two-sided slot antenna made on plates 2-3 are equal in value to each other. The maximums of the lobes in the experimental antenna pattern, performed on plates 4-5, differ from each other by 1.07 times. The experimental radiation patterns of the first and second of the aforementioned antennas at the minus three dB level are already calculated by approximately 15%.

Figure 11 shows the experimental and calculated amplitude radiation patterns of the turnstile antenna normalized with respect to the rms value. In this case, the first and second two-way slot antennas are fed through a directional coupler with signals of equal amplitude with a phase shift of 90 °.

The greatest deviations of the experimental antenna pattern from the circle are ± 1.5 dB.

Second turnstile antenna prototype A second turnstile antenna prototype was made (Fig. 12). The second antenna layout is different from the first by wiring the feeders. The first 101 and second 102 copper tubes were added to the layout. The first tube is located on the surface of the first plate 2. The end face of the tube 101 is aligned with the edge 28 of the slit 27 on the plate 2. Over the entire length of the tube contacting the plate, it has galvanic contact with the plate due to soldering. The first feeder 14 is laid inside the tube 101. When exiting the tube, the cable braid has galvanic contact around the entire perimeter of the tube end and, accordingly, with the plate 2. In the area immediately beyond the edge 28, the cable sheath and the outer cable conductor are removed, the central conductor 34 of the cable 14 is extended into the region slots and soldered to the edge 29 of the slit 27 on the second plate 3. The end of the tube 102 is aligned with the edge 31 of the slit 30 on the plate 4. Over the entire length of the contact of the tube with the plate, it has galvanic contact with the plate by soldering. The second feeder 15 is laid inside the tube 102. When leaving the tube, the cable sheath has galvanic contact around the entire perimeter of the end of the tube. In the area immediately beyond the edge 31, the sheath and the outer conductor of the cable are removed, the central conductor 38 of the cable 15 is extended into the region of the slit 30 and soldered to the edge 32 of the slit on the fourth plate 5.

In Fig.13 shows the normalized experimental radiation pattern in the plane of the vector E of the two-sided slot antenna with a slit 27. In Fig.14 shows the normalized experimental radiation pattern in the plane of the vector E of the two-sided slotted antenna with slit 30. In Fig.15 shows the normalized experimental radiation pattern of the second the layout of the turnstile antenna in the plane of the vector E. The normalization of the diagrams in Fig.13-15 made relative to the mean square signal level in the plane of the vector E.

For comparison, FIGS. 13-15 show design patterns of bi-directional slot antennas and a turnstile antenna. The maximums of the lobes in the experimental radiation pattern of a double-sided slot antenna made on plates 2 and 3 differ in magnitude by 1.05 times. The maximums of the lobes in the experimental radiation pattern of the antenna, made on plates 4 and 5, also differ by 1.05 times from each other. The experimental radiation patterns of the first and second of the aforementioned antennas are already estimated at about 4%.

Fig. 15 shows the experimental and calculated amplitude directivity patterns of the turnstile antenna in the plane of the vector E normalized with respect to the rms value. The first and second two-sided slot antennas are fed through the directional coupler with signals of equal amplitude with a phase shift of 90 °.

The largest deviations of the experimental radiation pattern of the antenna from the circle are +0.42 dB and -0.72 dB. The largest deviations of the calculated antenna pattern from the circle are +0.17 dB and -0.35 dB.

As noted above, in the experiment with the first prototype, significant differences are observed in the level of the bottom lobes, the width of the lobes, in the form of the radiation pattern of the first and second two-sided slot antennas. These differences are explained by the fact that in the desire for simplicity of design, proper galvanic contact between the external conductor of the coaxial cable (braid of the coaxial cable RK-50-2-11) and the surface of the plate was not performed. The external conductor connected to the plate (ground) only at one point in the vicinity of the edge of the slot. As a result, a transmission line was created consisting of the outer side of the outer cable conductor, the surface of the plate, between which there is a dielectric in the form of a cable sheath. In this case, a conductor (wire) connecting the external conductor of the cable and the plate, acts as the causative agent of electromagnetic waves in the aforementioned transmission line. The input impedance of the aforementioned transmission line turns out to be connected in parallel to the input impedance of the antenna, which substantially depends on how the cable is laid on the plate surface and beyond. As a result, the experiment exhibits some instability in measuring the input impedance of the antenna and VSWR in the transmission line. As a result of the radiation of the waves by the mentioned transmission line, asymmetry is observed in the lobes of the antenna radiation pattern. With the introduction of the first 101 and second tubular 102 shields into the second antenna layout (Fig. 12) and the connection of tubular shields with plates and coaxial cables with tubular shields and plates, as described above, the instability in the measurement of matching of the antenna with the feeder disappears, asymmetry decreases in the petals of the radiation pattern of the turnstile antenna.

Thus, due to the introduction of tubular shields, ensuring proper galvanic connection of tubular shields with plates by soldering them over the entire area of placement of tubular shields on the plates and connecting the external conductor of the cable to the end of the tubular screen, the non-uniformity of the experimental radiation pattern in the E plane of ± 1.5 dB is eliminated to a value close to the calculated ± 0.3 dB. On Fig presents the dependence of the VSWR on the frequency for the sample antenna of the present invention. As can be seen from the graph in FIG. 16, the matching bandwidth at 1.23 is at least 66 percent of the average frequency of the range.

Antenna application

The antenna can be used as a transmitting, receiving, or transmitting antenna in VHF and microwave systems in which it is required to provide horizontal polarization of the radiation field with a radiation pattern in the form of a circle in the horizontal plane in a wide frequency range. In particular, such antennas will find application for the transmission and reception of radio signals, television signals, in blind landing systems for aircraft, in aerodrome radio navigation beacons and other radio engineering and infocommunication systems.

Claims (3)

1. Broadband turnstile slot antenna, containing many pairs of conductive plates, each pair of plates is located in one of N planes, where N≥1, power divider and transmission lines of electromagnetic energy, many M vertical racks with holes, where M≥2, N devices matching, upper and lower brackets, while the set of N planes forms a bundle of planes with a vertical axis; the contour of each plate consists of a rectilinear vertical edge with K ledges, where K≥1, the upper edge, the lower edge and the rectilinear vertical edge, the opposite edge with the ledges; each plate with a vertical edge with ledges aligned with the aforementioned axis of the beam, and the plate is galvanically connected to each other with the formation of ledges K cracks; racks are connected to the upper and lower brackets with the formation of the antenna support; the plates are connected to the antenna support, characterized in that it further comprises N tubular screens, each plate additionally having L vertical slots, where L≥1, and P horizontal slots, where P≥0, with each of N tubular screens being located on one of these N pairs of plates with the formation of galvanic contact with the plate at the site of contact of the screen with the plate; one of the ends of the tubular screen is located in close proximity to the edge of the corresponding slit, a part of the screen with the other end is displayed through the hole in the rack outside the plate; each transmission line to N slots is placed inside the corresponding tubular screen, while the outer conductor at the end of each transmission line is galvanically connected to one of the plates in each of the aforementioned plate pairs and to the end of the corresponding tubular screen, and the central conductor is continued into the gap region and is further connected with the Central conductor of the respective matching device, galvanically coupled to a second plate from said pair of plates; transmission lines at their second ends are connected to a power divider. 2. The broadband turnstile slot antenna according to claim 1, characterized in that it comprises first and second metal plates lying in the first plane, third and fourth metal plates lying in the second plane, said first and second planes form 90-degree dihedral angles with a vertical axis, four racks, the first and second transmission lines used the first and second coaxial cables, a three-decibel quadrature directional coupler was used as a power divider; on the first, second, third and fourth plates on the edges aligned with the axis of intersection of the planes, cuts are made, forming ledges on the said edges; the aforementioned first, second, third and fourth plates are galvanically connected to each other by the edges on which the steps are made, thus forming in the plan a cross and a vertical axis of symmetry of the antenna, while the steps on the first and second plates form the first slot, and the steps on the third and fourth plates at the junction of the plates form a second slot, and the axis of the slots coincide with each other and with the axis of symmetry of the antenna; said first to fourth plates with straight vertical edges connected to respective uprights with holes; on each plate, an additional two vertical slots are made; the lengths of the additional slits are 0.34λ and 0.28λ, the slots are located at a distance of 0.09λ from the antenna axis and 0.28λ, respectively; the first tubular screen is located on the first plate, the second tubular screen is located on the third plate with the formation of galvanic contact with the corresponding plate in the area of contact of the screen with the plate; one of the ends of each tubular screen is located in close proximity to the edge of the corresponding slit, a part of the screen with the other end is brought out through the hole in the rack outside the plate; the transmission lines to the slots each are placed inside the corresponding tubular screen, while the end of the outer conductor of the first coaxial cable is galvanically connected to the first plate and to the end of the first screen, the end of the outer conductor of the second coaxial cable is galvanically connected to the third plate and to the end of the second tubular screen; the central conductors of the coaxial cables are continued in the region of the slots and are further connected to the central conductors of the respective matching devices galvanically connected to the second and fourth plates, respectively; transmission lines at their second ends are connected to a power divider. 3. The antenna system according to claim 1, characterized in that it contains a power divider into 8 directions, 8 feeders; the first, second, third and fourth plates are 4λ × 0.4λ (λ is the wavelength); the slots on the axis of the antenna have dimensions 0.5λ × 0.04λ, are located at a distance of 0.75 wavelength from each other at the middle frequency of the operating frequency range; the lengths of the additional slits are 0.34λ and 0.28λ, the slots are located from the antenna axis at a distance of 0.09λ and 0.28λ, respectively; aluminum channels with a section of 30 × 30 mm are used as racks²; the channels are interconnected using the upper and lower brackets with the formation of the antenna support; the channels are located at the corners of the square and the wide side (shelf) facing the axis of the cross; each of the eight radio frequency cables from the power divider located below the lower bracket is led up through the hole in the lower bracket, laid inside the corresponding channel, inserted into the tubular screen, and together with the screen through the hole in the wide wall of the channel, is brought out of it and laid along the plate, with the external cable conductor is galvanically connected to the plate and the end of the tubular screen, and the central conductor is continued into the gap region and in the gap region is connected to the central conductor of the matching terminal viscous feeder outer conductor is galvanically coupled to the other plate, lying in the same plane as said first plate, the second ends of the cables are connected to a power divider 8 directions.

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