RU2359376C1 - Corner antenna - Google Patents

Abstract

FIELD: physics, radio.

SUBSTANCE: invention is related to the field of radio engineering, namely, to corner antennas, also to antenna arrays for cellular communication systems, which are intended both for transmission and reception of radio signals. Antenna includes row of radiators, reflector, power supply circuit with two high-frequency sockets and summator-dividers and divisors and radiolucent covering. Every pair of radiators is made in the form of circuit board with two orthogonally installed printed radiators in the form of "Maltese cross". Halves of "Maltese cross" are connected to each other, have zero resistance to DC. Every circuit board is fixed to reflector by two stakes and two external braids of coaxial cable. Two radiators are connected crosswise by links to supply cables. Pairs of crosswise connected radiators are installed along longitudinal axis of antenna to create antenna array. In antenna technical solutions are used that increase uncoupling value between channels. Arrangement of radiators makes it possible to use technology of printed circuit boards in their manufacturing, which simplifies process of corner antenna serial production.

EFFECT: creation of corner antenna with double polarisation of ±45 degrees, with required shape of directional pattern, high level of uncoupling between channels and low level of VSWR in range of frequencies.

5 cl, 6 dwg

Description

The invention relates to the field of radio engineering, in particular to panel antennas, including panel antenna arrays for cellular communication systems, intended for both transmission and reception of radio signals.

Known panel antennas containing linearly arranged emitters in the form of a metal frame with a slit of the same (linear) polarization and a reflector, for example RU 2273079, H01Q 21/08, published 03/27/2006

Panel antennas are also known, containing crosswise connected orthogonal polarization emitters located along the longitudinal axis of the antenna, and a reflector, for example, RU 2225663, H01Q 1/38, published on March 10, 2004.

The problem to which the present invention is directed is to provide an antenna operating on two orthogonal polarizations, having the reception and transmission characteristics necessary for cellular communication systems, in particular, the desired radiation pattern, the required level of isolation between channels, while reducing the VSWR of each of two antenna inputs, and being economical to manufacture.

The solution to this problem is an antenna that includes at least one board (or several boards) made of dielectric material with two orthogonally located printed emitters, comprising the shape of the "Maltese cross" (the term "Maltese cross" is also known as the "eight-pointed cross ", as formed by the combination of four copies. Source: Foley J. Encyclopedia of Signs and Symbols. M., 1997). Electrically, two emitters are a single element (in direct current, both emitters are closed to each other). This provides zero DC resistance in each channel. The fastening elements of the emitter board (posts and external metal sheaths of cables) are simultaneously decoupling devices of two orthogonal channels, which greatly simplifies the design of the panel antenna.

The power supply of two cross-shaped emitters is made by two supply coaxial cables through two metal jumpers located parallel to the board plane and perpendicular to each other.

The board is mounted on the reflector on two metal posts and two external metal braids of the high-frequency cable. The metal posts and two external metal braids of the cable are electrically connected to the reflector and the printed emitters and at the same time are decoupling elements of the two channels (+ 45 ° and -45 °). In the case of using several emitter boards, jumpers are installed alternating 180 ° (for example: for the channel of the first board (+ 45 °), bend from the top, for the channel of the second board (+ 45 °) bend from the bottom, etc.). The designs of both jumpers are the same. The alternation of the jumper turns allows you to reduce the VSWR and ensure the same dependence of the VSWR in each channel.

The antenna contains two or more emitters with the same polarization, the planes of which are located along the longitudinal axis of the antenna, or at least one pair of crosswise connected emitters, the planes of which intersect at an angle of 90 °. This allows for the functioning of two receiving and transmitting channels with orthogonal polarization ± 45 ° relative to the longitudinal axis of the antenna.

The boards of the cross-connected emitters are installed along the longitudinal axis of the antenna with the parallel arrangement of emitters of the same polarization (+ 45 ° or -45 °) relative to the longitudinal axis of the panel antenna.

The preferred dielectric substrate material of the emitter board is fiberglass. For convenience of fastening jumpers in the center of the board has a hole. The reflector is a layer of metal foil (mainly copper) on a fiberglass plate. The reflector can also be made in the form of a plate of metal.

A variant of combining the reflector and the antenna body is possible. In this case, the power circuit is located directly on such a reflector (an antenna design option without a basement).

Additional elements of the isolation of the channels can be wires located symmetrically between each pair of emitter boards. One end of the wire is mounted on the printed circuit board of the emitters, the other - on the reflector, the angle of inclination of the wire to the plane of the reflector from 30 to 60 degrees. All wires are parallel to each other. The predominant material of the wire is copper.

The antenna is equipped with two identical power circuits for connecting the transmitting and receiving equipment. Each power circuit includes an adder divider and a high-frequency connector. The adder divider can be performed either on coaxial cable segments with different wave impedance, or in the form of a printed circuit.

The antenna is housed in a metal housing (primarily aluminum alloy), which can be streamlined. The power circuit is located in the basement of the housing, on the back of the reflector. To protect against external influences, the panel antenna is equipped with a radio-transparent cover of good aerodynamic shape, made of fiberglass.

Figure 1 shows a General view of the emitter board from the reflector in the form of a "Maltese cross" (emitter topology);

figure 2 is a view of the radiator board from the side of the translucent shelter with two supply jumpers;

figure 3 shows the design of two jumpers on the emitter board;

figure 4 shows a structural power diagram (diagonal cross-section of the emitter board) of the emitter - half of the "Maltese cross";

figure 5 shows an example of a panel antenna with six emitter boards without radiotransparent shelter;

figure 6 shows a General view of the antenna in the casing with a radiotransparent shelter.

The antenna contains at least one board 1 with two emitters in the form of halves of the "Maltese cross" 2. The board with emitters is a dielectric substrate made, for example, of fiberglass, on the surface of which there are two emitters made of metal, for example of copper, in the shape of the "Maltese cross."

The length of the middle line of the emitter (half of the "Maltese cross") is chosen equal to 2λavg., Where λavg. - the average wavelength of the panel antenna. The shape and dimensions of the emitter elements (the “Maltese cross”) and the dielectric parameters of the material of the emitter board are selected from the requirements of the necessary coordination (VSWR) in the frequency range and from the requirements to ensure the necessary radiation patterns. Both emitters (halves of the "Maltese cross") are electrically connected. This ensures zero DC resistance at the inputs of the panel antenna.

Emitters are located on the reflector side. The reflector 3 is a layer of foil made of metal (mainly copper) on a plate of fiberglass 4. The reflector can also be made in the form of a solid plate of metal.

The antenna body 13 can be used as a reflector in the antenna design. In this case, the antenna will not have a basement, and the power circuit elements will be placed directly on the reflector.

The emitter board 1 is fastened and each emitter is electromagnetically energized by means of a coaxial cable 5. The board is mounted parallel to the reflector on two metal posts 6, for example, made of brass and two metal parts of the cable braids 7. The columns of metal 6 and parts of the cable braids 7 are electrically connected (soldered) on the one hand to the reflector 3, on the other hand - to the emitters of the board 2.

The distance from the emitter boards to the reflector is selected from several requirements: the width of the radiation pattern of the panel antenna, the minimum value of the VSWR in the frequency range and the required level of isolation between the channels. The distance from the emitter boards to the reflector is constant for all antenna emitter boards and ranges from 0.1λsr. up to 0.3λavg., where λavg. - the average wavelength of the panel antenna.

The central veins of the cable of the emitter 8 are electrically connected (soldered) to the jumper 9, the second end of the metal jumper through a screw 10 is electrically connected to the metal column 6 and the emitter 2. For convenience of mounting the jumpers in the center of the board, a hole 11 can be made.

Both emitters and batteries for the board have the same design. Such a design of the emitters allows for a wide antenna matching band and a high level of isolation of two channels with a high radiation pattern stability (weak dependence of the radiation pattern of each channel on the operating frequency).

The VSWR level reduction in the frequency band is facilitated by the alternation of 180 ° turn of the jumpers (for example: for the channel of the first board + 45 ° bend from the top, for the channel of the second board + 45 ° bend from the bottom, etc.). In addition, this solution allows you to make both channels of the panel antenna almost identical in VSWR.

Additional elements of the isolation of the channels in the frequency range can be pieces of wire 11 located symmetrically between each pair of emitter boards. One end of the wire segment is mounted on the printed circuit board of the emitters, the other - on the reflector, the angle of inclination of the wire segment to the plane of the reflector from 30 to 60 degrees. Pieces of wire lie in planes - perpendicular to the reflector and parallel to each other.

The planes of the wire segments are located symmetrically from the axis of the panel antenna at a distance from each other from 0.4λ sr. up to 0.6λ avg., where λ avg. - the average wavelength of the panel antenna. The diameter of the wire segments is the same for all elements of the panel antenna and can range from 0.002λsr. up to 0.012λ avg., where λ avg. - the average wavelength of the panel antenna. All wires are parallel to each other. The preferred material for the wire segments is copper.

Each of the emitters of the same polarization (+ 45 ° or -45 °) is connected by a coaxial cable 5 with its own power circuit, including an adder-divider and a high-frequency connector 12. An adder-divider (not shown) can be made on segments of high-frequency cables with different wave impedances or in the form of a printed circuit.

The antenna is placed in a casing of metal 13 (mainly of aluminum alloy), which can be streamlined. The power circuit is located in the basement of the housing, on the back of the reflector. To protect against external influences, the panel antenna is equipped with a radio-transparent cover of a good aerodynamic shape 14 made of fiberglass.

Consider the operation of the antenna for reception. The incident electromagnetic wave excites signals in pairs of crosswise connected emitters 2, which through the jumpers 9 through the supply coaxial cables 5 enter the power circuit with an adder-divider, which provides the combination of these signals with the weights and phase incursions specified in the calculation of the adder-divider. Next, the signals are transmitted through a coaxial cable to connector 12 (in each of the channels), from which they enter the transmitting and receiving equipment.

When the antenna is transmitting, the signal from the transmitter of the receiving and transmitting equipment (not shown) is fed to connector 12 (in each channel) and transmitted through the coaxial cable to the adder-divider, which provides signal division in the ratio specified in the calculation of the adder-divider. The signals obtained as a result of dividing by supplying coaxial cables 5 through jumpers 9 are fed to pairs of crosswise connected emitters, each of which excites an electromagnetic wave in space.

The flat design of the emitters, mechanically and electrically connected by metal braids of cables and columns with a reflector, allows you to create a simple (economical to manufacture) and simultaneously with the desired radiation patterns panel antenna operating on two orthogonal polarizations, with a high level of isolation between channels, a low value of VSWR in frequency range and zero DC resistance.

Claims (5)

1. A panel antenna, consisting of one pair or several pairs of orthogonal emitters, each of the emitters is powered by a coaxial cable, two adders-dividers, two connectors for connecting transceiver equipment, a reflector and a metal housing, while a pair of orthogonal emitters is made in the form of one printed an element in the form of a "Maltese cross" on the reflector side, on one board of dielectric material, so that each of the two orthogonal emitters is dc-locked to each other, morning conductors of emitter cables are crosswise connected by jumpers with other halves of emitters and with metal posts, external metal sheaths of cables are connected with reflector and halves of emitters, posts are connected with reflector and other halves of emitters, the plane of boards with emitters parallel to the reflector, each emitter board is mounted on two metal sheaths of semi-rigid cables and two metal posts. 2. The panel antenna according to claim 1, characterized in that it contains elements of additional isolation of the channels in the form of wire segments located between each pair of emitter boards, one end of the wire segment is mounted on the emitter board, the other on the reflector, the angle of inclination of the wire to the plane of the reflector from 30 up to 60 degrees, the pieces of wire of each row are parallel to each other, the pieces of wire are located symmetrically from the axis of the panel antenna at a distance from each other from 0.4 A cf. up to 0.6 A cf., where A cf. - the average wavelength of the panel antenna, the diameter of the wire segments is the same for all elements of the panel antenna and ranges from 0.002 / 1 sr. up to 0.012 / 1 sr, where A sr. - the average wavelength of the panel antenna. 3. The panel antenna according to claim 1, characterized in that a metal casing is used as a reflector. 4. The panel antenna according to claim 1, characterized in that several pairs of orthogonal emitters are made on one common board of dielectric material. 5. The panel antenna according to claim 1, characterized in that it includes a radiotransparent shelter.

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