Broadband turnstile slit antenna. RU patent 2510970.

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

The technical field to which the invention relates

The invention refers to the radio antennas, in particular to a broadband antenna systems with horizontal polarization of the radiation field with circular radiation pattern in horizontal plane, low coefficient standing wave, 1.15 and less, in a wide band of frequencies. Such antenna is required to transmit and receive radio signals, television signals in the systems blind landing, navigation beacons and other radio systems.

The level of technology

The prior art broadband turnstile slotted antenna (RF patent №2401492 "Broadband turnstile slotted antenna", IPC H01Q 13/00, publ. 10.10.2010), selected as a prototype. This antenna contains many pairs of conductive plates, each pair plates is located in one of N planes, where N > 1, power splitter and line transmission of electromagnetic energy, many M vertical racks with holes, where M & GE; 2, N devices approvals, upper and lower brackets, the set N planes form a beam with a vertical planes axis; the outline of each plate consists of a straight vertical edges To the ledges where To & GE; 1, the upper edge of the lower edges and straight vertical edge, opposite edge with ledges; each plate vertical edge with ledges combined with the said axis of the beam and plate galvanically connected with each other with the formation of the terraces To the slots; racks are connected with the upper and lower brackets with the formation of a support antenna; plates are connected with the support of the antenna.

However, the antenna has drawbacks. Her band coordination with the feeder at the level of standing wave ratio voltage (VSWR) below 1,15 limited by several TV channels. Another disadvantage is that the shape of the antenna directional diagram and coordination is affected by the location of the feeders on the plates.

Disclosure of the invention

Technical achievement of the present invention is an extension of the strip approval of antenna feeder, eliminating the dependence of its pattern and agreement on the location of the feeders on the plates.

The goal of the project is achieved by the fact that the antenna the system that contains many pairs of conductive plates, each pair of plates is located in one of N planes, where N > 1, power splitter and line transmission of electromagnetic energy, many M vertical racks with holes, where M & GE; 2, N devices approvals, upper and lower brackets, with many N planes forms a bunch of planes with a vertical axis; the outline of each plate consists of a straight vertical edges To the ledges where To & GE; 1, the upper edge of the lower edges and straight vertical edge, opposite edge with ledges; each plate vertical edge with ledges combined with the said axis of the beam and plate galvanically connected with each other with the formation of the terraces To the slots; racks are connected with the upper and lower brackets with the formation of a support antenna; plates are connected with the support of the antenna, additionally contains N tubular screens each plate is made additionally L vertical slits, where L & GE; 1, and P horizontal cracks, where P = 0, the each of the N tubular screens located on one of the N pairs of plates with the formation of galvanic contact with the plate at the site of contact screen plate; one of the ends of the tube screen is located right next to the edge of the appropriate slot, part of the screen with the other end is derived through the hole in the rack outside the plate; each line transfer to N cracks placed inside the appropriate tubular screen, with the external conductor at the end each lineage is galvanically connected with one of the plates in each of these pairs of plates and with the end of the relevant tubular screen, and the center conductor continued in the area slit and then connected to the Central conductor of the corresponding matching device connected galvanically with the second plate of these pairs of plates; the transmission line their second ends connected to the power splitter.

The introduction of advanced part of the antenna tube screens, placing them directly on the plates as stated above, placing them in feeders and galvanic connection feeders with ends and edges of the plates helped to eliminate the dependence of its pattern and agreement on the location of the feeders on the plates. Running on plates additional slots is possible to expand the band approval of antenna feeder up to 60%, which in particular provides simultaneous emission of television signals any television channels in UHF frequency range.

Brief description of drawings

Figure 1 presents in ISO broadband slit turnstile antenna disassembled with two pairs of plates in accordance with the present invention.

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

Figure 3 Dan top view antenna assembled, presented in figure 2.

Figure 4 presents another option broadband slit turnstile antenna disassembled, in which the third and fourth metal plate is designed as a flat plate.

Figure 5 shows another option broadband slit turnstile antenna in which the plate is the first and the fourth, third and second pairs combined with education direct spatial dihedral angles.

Figure 6 presents another option broadband slit turnstile antenna in which the plates are made with cut triangular form.

Figure 7 presents the first model turnstile slot antenna.

On Fig given Cartesian and spherical coordinate system.

Figure 9 shows a pattern of bilateral slot antenna, made on the plates 2 and 3 in the plane of the vector E is the first layout of the antenna.

Figure 10 shows a pattern of bilateral slot antenna, made on the plate 4 and 5 in the plane of the vector E is the first layout of the antenna.

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

On Fig presents the second layout of the antenna.

On Fig the calculated (solid lines) and experimental (dotted line) direction diagram in the second sample antenna, made on the plates 2 and 3 in the plane of the vector E. the second layout of the antenna.

On Fig the calculated (solid lines) and experimental (dotted line) direction diagram in the second sample antenna, made on the plate 4 and 5 in the plane of the vector E.

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

On Fig presents the dependence of VSWR of frequency for the pattern of the antenna according to the present invention.

Let us turn now to figure 1, which presents turnstile slotted antenna 1 with two pairs of plates in accordance with the present invention. The complementary elements start with the number 101. Antenna 1 contains the first 2, the second 3, 4 third and fourth 5 flat conductive plates, four hours 6, 7, 8 and 9, power splitter 10 with input 11 and with the first 12 and 13 second outputs, the first 14 and 15 second feeders, the first matching device 16, second matching device 17, upper and lower brackets (bracket not shown in figure 1), first 101 and second 102 tube screens, which have galvanic contact plates 2 and 4, respectively, from all areas of their contact with each other. All four plates of the same. Each of the plates 2-5 has a vertical edge 18 ledge 19, top edge of 20, the lower edge of 21 and straight vertical edge 22. Designation edges are on the fourth plate. On each of the plates 2-5 made a rectangular canal 103 and 104. Plate 2 and 3 are on the first plane 23, plate 4 and 5 are in the second plane 24, orthogonal to the plane 23. The line of intersection of the planes 23 and 24 - vertical straight line 25.

Plate 2-5 made of well-conductive material such as aluminum alloy, copper alloy or steel. You can use foiled dielectric plates. Stand 6, 7, 8 and 9, the upper and lower brackets can be made of aluminum, brass or steel pipes, channels, corners or other rental or high-frequency dielectric. As a feeder applied standard coaxial cable. Matching device 16 and 17 are made in the form of segments of the coaxial cable. Power splitter is calculated according to the well-known formulas given in textbooks on technical electrodynamics or in handbooks of devices of SHF. Fairing (not shown in figure 1) made of high-frequency dielectric.

The above devices are connected in the following way (figure 2). The first 2, the second 3, 4 third and fourth 5 plates galvanically connected by edges 18 education direct dihedral angles 26 with a total direct 25 - edge dihedral angle, hereinafter called the vertical axis 25 antenna. In terms of the resulting device has the shape of a cross (Figure 3). Ledges 19 on the edges of 18 on the first 2 and the second 3 plates with galvanic the wafers form the first crack 27 with edges 28 and 29, parallel to the axis of 25. Ledges 19 on edges 18 4 on the third and fourth 5 plates with galvanic the wafers form the other slit 30 with edges 31 and 32, parallel to the axis of 25. Stand 6, 7, 8 and 9 are made of metal, plates 2-5 connected with stands and using the upper and lower brackets with the formation of galvanic contact between the plates and counters, between the plates and the upper and lower brackets. The first tubular screen 101 has a galvanic contact with the first plate 2 all areas of their connection. Second tubular screen 102 has galvanic contact with a third plate 4 all areas of their connection.

One of the ends of tube screen 101 is located in close proximity to the edge of 28 cracks 27, the tubular part of the screen with the other end is derived through the hole in the rack 6 beyond plate; feeder 14 placed inside the first tubular screen, with the external conductor feeder galvanically connected to the plate 2 and referred to by the end of the first tube of the screen and the center conductor continued in the area cracks 27 and then connected to the Central conductor matching device 16, galvanically connected to the plate 3; feeder their second end is connected to the output 12 power splitter 10.

One of the ends of tube screen 102 located in close proximity to the edge of 31 cracks 30, the tubular part of the screen with the other end is derived through the hole in the rack 8 beyond plate; feeder 15 placed inside the second tubular screen, with the external conductor feeder galvanically connected to the plate 4 and mentioned by the end of the second tube of the screen and the center conductor continued in the area cracks 30 and then connected to the Central conductor matching device 17, galvanically connected to the plate 5; feeder their second end is connected to a power splitter 10.

The length of the first 14 and 15 second feeders are equal to each other. Rack 6-9 are attached to the upper and lower brackets to stiffen the antenna design. Bottom bracket has holes for mounting the antenna to a mast or tower. Top and bottom brackets executed in the form of a cross, disk, or other form.

In other variant of connection 6-9 hours connected to the upper and lower brackets, plates have galvanic contact with the upper and lower brackets, and thus between the plates and pillars formed gap. In other variant of connection plates are connected with the stand with the formation of galvanic contact hours is connected to the upper and lower brackets, and thus between the plates and the upper and lower brackets formed gaps.

In another embodiment, antenna 1 (Figure 4) 4 third and fourth 5 plates performed together as one plate 41, which made the mentioned gap 30, cracks 103 and 104.

In another embodiment, antenna 1 (Figure 5) first and fourth plate performed together in the form of dihedral plate 42, and the second and third plates are made in the form of dihedral plate 43. In dihedral plates 42 and 43 holes 44 and 45, which the galvanic connection plates 42 and 43 with each other form mentioned cracks 27 and 30.

Preferably plate 2-5 are rectangular in shape. However, there are plates of different configuration. Figure 6 shows an example of the execution of antennas with plates 2-5 with cut triangular form. Possible such configuration plates 2-5 that when connection is formed plate with the form, which is called "the wing of a bat".

The antenna operates in the mode of transmission as follows. Generator power at the input of 11 (3) of the attenuator 10, divided into two equal parts. Thus the output signals 12 and 13 of the divider equal in amplitude and are shifted in phase by 90 degrees. Crack 27 excited cut the center conductor 34 feeder 14, located in the area between the edges 28 and 29. Crack 30 excited cut the center conductor 38 feeder 15, located in the area between the edges 31 and 32.

Slotted antenna, implemented the first 2, the second 3 plates and crack 27, forms in the plane orthogonal to the axis 25, the first direction diagram in the form of "eight". In this case maxima beam is directed perpendicular to the plane 23, which are the first 2 and 3 second plate.

Slotted antenna implemented 4 third, fourth, 5 plates and crack 30, forms in the plane orthogonal to the axis 25, the second direction diagram in the form of "eight". In this case maxima beam is directed perpendicular to the plane 24, in which are located 4 third and fourth plate 5. As a result, when the graphical image of the "eight", showing mentioned the first and the second pattern, deployed in the horizontal plane relative to each other at 90 degrees. The signals emitted from the first and second slot antennas, shifted each other in the space phase by 90 degrees. In addition, in the space of signals emitted from the first and second slot antennas, is the direction diagram in the form of a circle.

The first model turnstile slot antenna

Was built the first model turnstile antenna (Fig.7). When describing this and subsequent samples antenna we refer to digital designations figure 1-4. The first model 1 consists of the first 2, the second 3, 4 third and fourth 5 plates, power splitter 10 in two directions, first 14 and 15 second feeder. Plate 2-5 made of tin-plated sheet metal thickness of 0,3 mm Layout is made as follows. Were made two copies of the plate size 400 x 210 mm 2 . In the centre of each plate is parallel to the side of 400 mm in length cut the gap with dimensions 275 x 20 mm 2 . The first copy of the plate is applied in the sample as a third 4 and 5 fourth plates with the second crack 30. For the first 2 and 3 second plate second copy is made of the plate was cut in a straight line, which coincides with the axis of the slit. Received two plates 2 and 3 soldered to the first instance of a plate with the formation of the first cracks 27. The result is a device that has in plan view of the cross. Dihedral angles formed by plates, each equal to 90 degrees. To the first plate near the edge of 28 cracks 27 soldered braid first feeder 14 - coaxial cable RK-50-2-21. The cable is laid directly on the plate. On the plot directly at the edge of 28 shell and external conductor cable is removed, the center conductor 34 coaxial cable 14 continued in the area cracks 27 and soldered to the edge of 29 cracks 27 on the second plate 3. The distance from the place of soldering cable to narrow bottom edges of the slit is 55 mm The third plate 4 in a vicinity of edges 31 cracks 30 soldered braid second feeder 15 - coaxial cable RK-50-2-21. On the plot directly at the edge of 31 shell and external conductor cable is removed, the center conductor 28 cable continued in the field of slot 9 and soldered to the edge of the slit 32 on the fourth plate 5. Designated desoldering first 14 and 15 second feeders to the plates posted on different sides from the center of gap. If counting the distance from narrow (bottom) end of the first cracks to the place desoldering second feeder, then the distance is 220 mm The first 14 and 15 second feeders, which are applied radio-frequency cable RK-50-2-21 have the same length. As of the attenuator 10 on two areas used 3 dB quadrature directional coupler on related strip lines, which, as is known, provides the division of power into two equal parts and 90 degree phase shift between the output signal.

On Fig presents a spherical coordinate system.

Figure 9 shows the normalized experimental and calculated pattern of bilateral slot antenna, made on the plates 2 and 3 in the plane of the vector E. Figure 10 shows the normalized experimental and calculated pattern of bilateral slot antenna, made on the plate 4 and 5 in the plane of the vector E. Figure 10 shows the normalized experimental and calculated pattern of the first layout turnstile antenna in the plane of the vector E. Normalization diagrams made regarding the RMS signal levels in the plane of the vector E.

The settlement pattern is found by solving an electrodynamic problem of direct temporary method. Boundary value problems formulated for an uninterrupted continuum, are reduced to the variational - and projective-difference models. Experimental pattern measured in the far zone method "towers".

The experimental and calculated pattern of bilateral slot antennas are symmetric lobe view (eight). Maxima petals in the experimental pattern of bilateral slot antenna, made on the plates 2-3, largest equal. Maxima petals in the experimental antenna pattern, made on the plates 4-5, differ from each other 1.07 times. Experimental pattern of the first and second of these antennas at minus three dB already estimated charts around 15%.

Figure 11 shows the normalized relative to the RMS value of the experimental and calculation of amplitude pattern turnstile antenna. While the first and the second bilateral slotted antenna is fed through the directional coupler signals of equal amplitude shifted in phase by 90 degrees.

The greatest deviations of the experimental antenna directional diagram from the circle ą1.5 dB.

For comparison on Fig-15 shows the estimated pattern of bilateral slot antennas and turnstile antenna. Maxima petals in the experimental pattern of bilateral slot antenna, made on the plates 2 and 3, the largest differ in 1.05 times. Maxima petals in the experimental antenna pattern, made on the plate 4 and 5, differ from each other also in 1.05 times. Experimental pattern of the first and second of these antennas is already estimated at around 4%.

On Fig shows the normalized relative to the RMS value of the experimental and calculation of amplitude pattern turnstile antenna in the plane of the vector E. While the first and the second bilateral slotted antenna is fed through the directional coupler signals of equal amplitude shifted in phase by 90 degrees.

The greatest deviations of the experimental antenna directional diagram from the circle +0,42 dB and -0,72 dB. The greatest deviation of the beam from the circle +0,17 dB and 0.35 dB.

As noted above, in the experiment with the first layout significant differences in the level of petals NAM, width petals, in the form of a pattern first and second bilateral slot antennas. These differences are explained by the fact that in the pursuit of simple construction was not completed shall galvanic contact between the outer conductor of the coaxial cable (wire coaxial cable RK-50-2-11) and the plate surface. The outer conductor is connected to the plate (was grounded only at one point in a vicinity of edges of the slit. The result was to create a transmission line, consisting of the external side of the outer conductor cable, surface plates, separated by a dielectric in the form of cable sheath. When a conductor (wire), connecting the external conductor and plate acts as the agent of electromagnetic waves in the mentioned transmission lines. The input impedance of the antenna is connected in parallel input resistance referred to a transmission line, which largely depends on how laid cable on the plate surface and beyond. In this experiment there was some instability in the dimension of the input impedance of the antenna and VSWR in the transmission line. Because of the emission of waves mentioned by the transmission line is observed asymmetry in the petals of the antenna directional diagram. With the introduction of the second layout antenna optional first 101 and second tubular 102 screens (Fig) and connection tube screens with plates and coaxial cables with tube screens and plates, as described above, disappears nestabilnost measuring the approval of antenna feeder, reduced asymmetry in the wings pattern turnstile antenna.

Thus, thanks to the introduction of tube screens, ensuring the proper galvanic connection tube screens with plates by soldering on all site hosting tube screens on the plate and connect the outer conductor cable with the end of tubular screen eliminated irregularity experimental direction diagram in the plane of the E ±1.5 dB to a value close to the rated ±0.3 dB. On Fig presents the dependence of VSWR of frequency for the pattern of the antenna according to the present invention. As can be seen from the consideration of schedule Fig, the bandwidth negotiation at the level of 1,23 is not less than 66 percent from the average frequency range.

Use of antenna

The antenna can be used as a transmitting, receiving or transmitting antenna systems on the UHF and SHF range where required, the horizontal polarization of the radiation field with a pattern in form of a circle in a horizontal plane in a wide frequency range. In particular, such antenna will be used for the transmission and reception of radio signals, television signals in the systems blind landing of aircraft, aerodrome navigation beacons and other radio engineering and communication systems.

1. Broadband turnstile slotted antenna containing many pairs of conductive plates, each pair of plates is located in one of N planes, where N > 1, power splitter and line transmission of electromagnetic energy, many M vertical racks with holes, where M & GE; 2, N devices approvals, upper and lower brackets, the set N planes forms a bunch of planes with a vertical axis; the outline of each plate consists of a straight vertical edges To the ledges where To & GE; 1, the upper edge of the lower edges and straight vertical edges, the opposite edge with ledges; each plate vertical edge with ledges combined with the said axis of the beam and plate galvanically connected with each other with the formation of the terraces To the slots; racks are connected with the upper and lower brackets with the formation of a support antenna; plates connected with the support of the antenna, characterized in that it additionally contains N tubular screens on each plate is made additionally L vertical slits, where L & GE; 1, and P horizontal cracks, where P = 0, the each of the N tubular screens located on one of the N pairs of plates with education galvanic contact with the plate at the site of contact screen plate; one of the ends of tube screen is located right next to the edge of the appropriate slot, part of the screen with the other end is derived through the hole in the rack outside the plate; each line transfer to N cracks placed inside the appropriate tubular screen, with the external conductor at the end of each transmission line galvanically connected with one of the plates in each of these pairs of plates and with the end of the relevant tubular screen, and the center conductor continued in the area slit and then connected to the Central conductor of the corresponding matching device, galvanically connected with the second plate of these pairs of plates; the transmission line their second ends connected to the power splitter.

2. Broadband turnstile slotted antenna according to claim 1, characterized the fact that contains the first and second metallic plates, laying in the first plane, third and fourth metallic plates, laying the second plane referred to the first and second plane form a 90-degree dihedral angles with a vertical axis, four hours, as the first and second transmission lines applied first and second coaxial cables, as a power splitter applied traditinally quadrature directional coupler; on the first, second, third and fourth plates on the edges, combined with the axis intersection of the planes made the cut, forming on these edges ledges; the first, second, third and fourth plate galvanically connected by edges, which made ledges, forming in cross plan and vertical symmetry axis of the antenna, with terraces on the first and second wafers form the first slot, and the terraces on the third and fourth plates at the junction plates form a second slot, and the axis of gaps coincides with the axis of symmetry of the antenna; the first-fourth plate straight vertical edges are connected with the corresponding enclosures with holes; on each the plate is made, two vertical slits; the length of the additional slots 0,34λ and 0,28λ, slots are located at some distance from the antenna axis at a distance of 0,09λ

and 0,28λ, respectively; the first tubular screen is located on the first plate, the second tubular screen is located on the third the plate with the formation of galvanic contact with the appropriate plate at the site of contact screen plate; one of the ends of each tube screen is located right next to the edge of the appropriate slot, part of the screen with the other end is derived through the hole in the rack for limits plate; a transmission line to the cracks each placed inside the appropriate tubular screen, while the end of the outer conductor of the first coaxial cable is galvanically connected to the first plate and with the end of the first screen, the end of the outer conductor of the second coaxial cable galvanically connected with the third plate and with the end of the second tubular screen; Central conductors coaxial cables continued in the field of cracks and then connected to the Central conductors appropriate matching devices, galvanically connected respectively with the second and fourth plates; the transmission line their second ends connected to the power splitter.