RU2580406C1 - Broadband directional zigzag quasi-shunt-fed antenna - Google Patents

Abstract

FIELD: radio engineering and communications.

SUBSTANCE: broadband directed zigzag quasi-shunt antenna is made in the shape of two loops of conductors in the form of squares. Branches of conductors are located along a common diagonal on both sides. Branches are open along the whole length and closed by shunts. Antenna curtain is symmetrically folded along the line of symmetry. Line of symmetry is perpendicular to the general diagonal. Antenna curtain is located in front of the reflector. Planes of the branches are located with an inclination to the centre. Points of formed active antenna curtain surfaces are located at a distance from the reflector equal to 0.2λ_min. - 0.2λ_max. ranges of operating radio wave lengths. Length of the squares' sides is comparable with 0.5λ_av. ranges of operating radio wave lengths.

EFFECT: simplified design and assembly of the device during installation and improvement of the antenna matching with the feeder with preservation of the antenna pattern in the specified working range.

2 cl, 4 dwg

Description

The invention relates to antenna technology and is intended for use as transceiver antennas, mainly in a wide version of individual television reception antennas for the decimeter wavelength range.

The trends of recent years in the development of wireless radio systems, using the decimeter wavelength range, reveal the widespread deployment of communications and broadcasting stations, office and home wireless networks and an all-encompassing intensive transition to digital terrestrial television. Features of work and the specifics of using the RF resource by the devices of these systems often require the use of different types of antennas, among which directional ones occupy a special place. In this part of the radio frequencies, the antenna size limits in relation to wavelengths have practically disappeared, which allows synthesizing antenna devices of combined designs for the expansion and implementation of a wide variety of characteristics with the implementation of the interpretation of classical elements of analogs of various types from other ranges.

Known broadband zigzag antenna with a reflector (Pat. RF №2122762, publ. 11/27/1998), containing an active vibrator-emitter in the form of two identical metal closed rhombic frames located symmetrically relative to the power points in the center of the antenna, and a flat reflector. To reduce the standing wave coefficient in the cable when the antenna is operating in a wide frequency range with an overlap factor of at least 1.5-2, the reflector is separated from the active vibrator-emitter at a distance of (0.2-0.25) λ _min . Each rhombic frame has the shape of a side surface in the form of a regular truncated pyramid, the side faces of which are trapezoids, with a lower base length comparable with (0.25-0.33) λ _max .

The disadvantages of the known invention are not a wide range of operating frequencies and the relative complexity of the manufacture and operation of an active surround vibrator-emitter.

Known rhombic antenna with a double reflector (Pat. RF №2334318, publ. September 20, 2008), containing wires located along the sides of the rhombus and forming a long line, on the one hand loaded with active resistance equal to its wave impedance, on the other hand connected to the power line. At a certain angle to the rhombus plane, to increase the directivity of the antenna at a small distance from the rhombus, the first flat conductive screen (reflector) is installed. The second reflector is identical to the first and is installed symmetrically to it relative to the plane of the rhombus. The intersection line of the reflector planes is perpendicular to the longitudinal diagonal of the rhombus.

The disadvantages of the known invention are the relative complexity of the manufacture and operation of the rhombic structure with isolation from the reflectors and the significant side radiation of the antenna with a double reflector.

As a prototype of the claimed technical solution of a broadband directional zigzag quasi-shunt antenna, a wire antenna is adopted (Pat. RF 2189093, publ. 09/10/2002, Fig. 1). To increase the KND and expand the operating frequency range, the known antenna is made in the form of two turns of wire in the form of squares with sides of 0.5λ _cf. located in one plane along a common diagonal in the form of two branches. The branches are open along the entire length of the antenna with the power node of the two-wire line at the points of contact of the squares with open sides in the center of the antenna.

The disadvantages of the prototype are not sufficiently significant range of operating frequencies while maintaining the coefficient of standing waves less than 2 and the relative complexity of manufacturing the structure when the insulation of the branch conductors between themselves and the installation location of the antenna.

The technical result to which the claimed invention is directed is to simplify the design and assembly of the device during installation, to improve the alignment of the antenna with the feed feeder while maintaining the directivity of the antenna in a given operating range.

This result is achieved in that the broadband directional zigzag quasi-shunt antenna contains an active web in the form of two turns of conductors in the form of squares located along the common diagonal on both sides in the form of two branches open along the entire length. The power node is located at the contact points of the squares with open sides in the center of the antenna. The canvas is symmetrically bent along a line perpendicular to the plane passing through the common diagonal, and is located in front of the reflector with the deviations of the formed branch planes towards the center, formed by changing the distance between the branch planes and the reflector. The distance of the open sides of the squares in the center of the antenna from the reflector is commensurate with 0.2λ _min. working wavelength, and the distance of the open sides of the outer corners of the squares from the reflector is commensurate with 0.2λ _max. working wavelength. Turns of squares with sides commensurate with 0.5λ _cf. working wavelength, made in the form of stranded wire conductors. The veins of the conductors of the sides of the squares of the active canvas, located in the plane of the branches of their squares, are brought together and closed to each other at open points of contact of the open sides. Conductor conductors are fan-separated to a distance commensurate with 0.1λ _max. working wavelength at angles remote from the common diagonal, and closed by jumpers. The middle parts of the conductors of the sides of the squares are interconnected by jumpers and connected by conductors to the reflector. These conductors are interconnected at points of the longitudinal axis of symmetry of the reflector, with each perpendicular to the longitudinal axis with the formation of peculiar shunts connected by their midpoints to the reflector.

The conductors of the branches of the active web can be made monolithic flat, of sheet material by stamping or sawing, as well as three-dimensional 3D printer manufacturing in borders and in a shape similar to figures formed by stranded wire conductors. At the same time, the branches can be made in one piece or in the execution of identical halves, if possible connect at the switching point to the power node.

For a specific implementation of the claimed technical solution, it is preferable to use the connecting conductors-shunts of the branches of the active web as the grounding fastener of the branches to the reflector. This provides ease of manufacture and rigidity of the antenna design, its increased operational reliability. To ensure lightning protection properties and the removal of static electricity, the corrosion elements of the antenna are coated with paint in which bronze powder is added in a ratio of at least 1:10.

The novelty in the device part is that zigzag turns of conductors of the active web from the midpoints of the side conductors, which are open along the entire length of the squares, are connected by conductors at the points of the longitudinal axis of symmetry of the reflector to each other, forming shunt circuits.

The novelty in the device part is seen in the fact that peculiar quasi-shunts provide artificial zero points and allow mechanical fastening of the web structure to the reflector without insulators in them.

The novelty in the device part is that in addition to shunting, the connecting conductors of quasi-shunts with lengths commensurate with 0.25λ _min. and 0.25λ _max. converging at an angle to the zero point and perpendicular to the axis of symmetry of the reflector, they participate in the operation of the antenna as polarized vibrators corresponding to the polarization of the zigzag active web.

The novelty in the device part is seen in the fact that the canvas is symmetrically bent and located in front of the reflector with deviations of the formed branch planes to the center, formed by changing the distance between the branch planes and the reflector, providing a logarithmic dependence of the distance change to create optimal working areas, the active canvas is a reflector when changing operating frequencies.

The novelty in the device part is seen in the fact that the canvas symmetrically bent along a line perpendicular to the plane passing through the common diagonal, with the deviations of the formed branch planes towards the center, due to the operation in the classical shortened rhombic antenna mode in the high-frequency part of the working range of radio wavelengths, provides directivity diagrams of longitudinally spaced squares, further increasing directivity.

Industrial applicability of the proposed technical solution is seen in the comparative simplicity of manufacture, high electrical characteristics, the possibility of use in small-scale production and on an industrial basis at a high competitive level. Compared with the well-known, practically used analogues of television antennas of the “Polish grid” type, the claimed broadband directional zigzag quasi-shunt antenna in the entire decimeter range of terrestrial television can be used without antenna amplifiers.

The proposed broadband zigzag quasi-shunt antenna is illustrated by the drawings shown in FIG. 1-4.

In FIG. 1 is a sketch of a general view of the claimed broadband directional zigzag quasi-shunt antenna; in FIG. 2 - radiation patterns in horizontal and vertical planes; in FIG. 3 is a graph of the variation of the standing wave coefficient in the operating range; in FIG. 4 - graphs of changes in gain and protective coefficient in the operating range.

The inventive broadband directional zigzag quasi-shunt antenna contains an active web 1 in the form of two turns 2 of conductors 3 in the form of squares 4 located along the common diagonal 5 on both sides in the form of two branches 6. Branches 6 are open along the entire length, with the power node 7 at the points of contact 4 squares with open sides in the center of the antenna. The blade 1 is symmetrically bent along the line 8, perpendicular to the plane passing through the common diagonal 5, and is located in front of the reflector 9. The slope of the formed planes of the branches 6 to the center is formed due to the distance of 10 open sides of the squares 4 in the center of the antenna from the reflector 9, commensurate with 0 , 2λ _min. working wavelength and distance 11 open sides of the outer corners 12 squares 4 from the reflector 9, commensurate with 0.2λ _{max ..} working wavelength. Coils of 2 sides of squares 4, commensurate with 0.5λ _cf. working wavelength in the form of wire conductors 3, made stranded. The conductors of the conductors of 3 sides of the squares 4, located in the plane of the branches of 6, are brought together and closed to each other, at the open points of contact of the open sides of the squares 4. The conductors of the conductors of 3 sides of the squares 4, located in the plane of the branches of 6, are fan-divided to a distance commensurate with 0, 1λ _max. working wavelength at angles 13, remote from the common diagonal, and closed by jumpers 14 to each other. The middle parts of the conductors 3 sides of the squares 4 are closed by jumpers 15 between themselves and the conductors-shunts 16 and 17 are connected at the points of the longitudinal axis of symmetry 18 of the reflector 9 with each other and with the reflector 9 when each conductor is perpendicular to it.

Broadband directional zigzag quasi-shunt antenna works as follows.

In the low-frequency part of the operating range of radio wavelengths, the conductors of 3 sides of squares 4 are commensurate with 0.25λ _max. , the vertices of the open outer corners 12 are duplicated by the closed angle of the conductors-shunts 17, increased in length, with an increase in the inclination of the plane of the branches 6, and closed reduced by the location closer to the center of the conductors 16, by shunting, increase the input impedance of the antenna. In the low-frequency part of the operating range of radio wavelengths, the antenna works similar to the operation of the Harchenko classic biquadratic loop antenna with an increased input impedance. In the high-frequency part of the operating range of radio wavelengths, the conductors of branches 6 in length exceed λ _min. , fan-like dilution of stranded conductors at angles 13 that are remote from the common diagonal and closed by jumpers 14 with each other while reducing and closing together at open points of contact of the non-closed sides of squares 4, align linear characteristics of long lines. In the branches 6, loaded with grounded, increased placement farther from the center by shunts from conductors 17, the reflection of the waves is neutralized. In the high-frequency part of the working range of radio wavelengths, the antenna works similar to the work of a classic shortened rhombic antenna with the reduction of the radiation patterns of longitudinally spaced squares due to the formation of an angle between them. In the mid-frequency part of the operating range of radio wave lengths with conductors of 3 sides of squares 4, commensurate with 0.5λ _cf. , the antenna works in an intermediate, from open, mode with a larger aperture. Peculiar shunts from conductors 16 and 17, on the one hand, provide artificial zero points and grounding to the reflector 9 of the active antenna sheet, and on the other, with a total pair length commensurate with 0.5λ _cf. , with a V-shaped configuration and a perpendicular arrangement to the symmetry axis 18 of the reflector 9 and to the common diagonal 5, the antennas with polarization corresponding to the polarization of the active web participate in the operation. In addition, the canvas is symmetrically bent along line 8 and is located in front of the reflector 9, with the deviations of the formed planes of the branches 6 to the power node 7 in the center. This is ensured by changing the distance 10-11 between the planes of the branches 6 and the reflector 9, creating a logarithmic dependence of the change in distance along the active antenna sheet, to create optimal working areas: the active canvas is a reflector when changing operating frequencies, as well as to provide longitudinal information located squares. All this combined allows you to increase the broadband antenna with an overlap factor of more than 2, stability in the frequency range of the coefficient of standing waves, almost less than 2, and range unidirectionality with low side radiation while simplifying the insulator-free design of the antenna device according to the claimed technical solution.

The operation of a broadband directional zigzag quasi-shunt antenna was modeled in the MMANA program with explicit confirmation of the arguments presented by the results shown in FIG. 2-4.

The proposed antenna allows you to increase the broadband frequency range, to ensure the stability of the standing wave coefficient in the range of operating wavelengths, unidirectional range and lightning protection with a simplified design.

Claims (2)

1. A broadband directional zigzag quasi-shunt antenna with an active web in the form of two turns of conductors in the form of squares located along the common diagonal on both sides in the form of two branches open along the entire length, with the power node at the points of contact of the squares with open sides in the center of the antenna, characterized in that the canvas is symmetrically bent along a line perpendicular to the plane passing through the common diagonal, and is located in front of the reflector with deviations of the formed branch planes to the center, created due to the distances of the open sides of the squares in the center of the antenna from the reflector, commensurate with 0.2 λ _min. working wavelength and the distances of the open sides of the outer corners of the squares from the reflector, commensurate with 0.2 λ _max. working wavelength, turns of squares with sides commensurate with 0.5 λ _cf. working wavelengths, made in the form of stranded wire conductors, the conductors of the sides of which are located in the plane of the branches of their squares, brought together and closed to each other at open points of contact of the open sides, with fan-spaced apart distance, commensurate with 0.1 λ _max. the working wavelength at angles remote from the common diagonal and closed by jumpers with each other, and the middle parts of the conductors of the sides of the squares are closed by jumpers between themselves and the conductors-shunts are connected at the points of the longitudinal axis of symmetry of the reflector with each other and with the reflector when each conductor is perpendicular to it. 2. The antenna according to claim 1, characterized in that the conductors of the branches of the fabric are made flat, of sheet material or 3D printer three-dimensional manufacture in borders and in a shape similar to figures formed by multicore wire conductors.

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