CN210956990U - Ultra-wideband dipole antenna - Google Patents

Abstract

The application discloses ultra wide band dipole antenna, including dielectric plate, coupling minor matters structure and two dipole arms that the shape is the same, dipole arm is hollow curved surface casing to use the dielectric plate to set up as central plane symmetry, in order to regard as dipole antenna's broadband feed. Wherein the curved surface of each dipole arm comprises an ellipsoid curved surface and an arc curved surface. The coupling branch structure comprises four coupling branches symmetrically arranged around two dipole arms to serve as a multiband source of the dipole antenna, wherein each coupling branch is a broken line structure with bent strip metal, the height of the ultra-wide dipole antenna is 500 mm, and a curve cone is adopted as a broadband feeding strategy for feeding, so that a pair of dipole antennas can meet a wider frequency range, the technical problems that the common dipole antenna is large in size and needs multi-segment design are solved, and the requirements of various occasions are met.

Description

Ultra-wideband dipole antenna

Technical Field

The application relates to the technical field of multi-frequency broadband dipole antennas, in particular to an ultra-wideband dipole antenna.

Background

Dipole antennas are widely used in mobile communication devices and microwave energy collection and transmission fields due to their simple structure, low manufacturing cost and good performance. A conventional dipole antenna, consisting of two conductors, is fed at a central location, has a total length of about half a wavelength, and is the basic element of most antennas. The dipole antenna has certain improvement in gain directional diagram performance compared with a monopole antenna, can obtain satisfactory directional diagram characteristics, and has good radiation characteristics, wavelength shortening effect and resonance characteristics. By controlling the relationship among the current amplitude, the phase and the spatial position on the dipole, the dipole antenna can be widely applied to base station antennas, circularly polarized antennas and multiple-input multiple-output (MIMO) antennas. As the antenna of the wireless communication eye directly affects the communication quality and efficiency, in the big data era of mass data transmission, it puts higher and higher requirements on the broadband and multi-frequency of the communication device, and therefore, the support of the adaptive broadband multi-frequency antenna is more needed. The miniaturization of the equipment is more and more strict, and the requirement on the size of the antenna is more and more strict. With the simultaneous existence of multiple communication standards or standards of modern communication systems, the requirements for antennas are also developing towards broadband multi-frequency and miniaturization. In order to realize broadband multi-frequency, a slotline and a loading parasitic element are generally adopted on an antenna. The slotline approach may introduce unwanted frequencies while achieving the introduction of multiple resonant frequencies. Although the adoption of the mode of loading the parasitic element realizes multi-frequency, the mutual coupling among all branches can be brought, and the size of the antenna is increased. Therefore, it is a urgent need in the wireless communication field to design a dipole antenna with small size, multiple frequency bands and wide band.

Disclosure of Invention

The technical problem that this application mainly solved is big and the narrow technical problem of frequency band of broadband dipole antenna size among the prior art.

According to a first aspect, an embodiment provides an ultra-wideband dipole antenna, including a dielectric plate, a coupling branch structure and two dipole arms with the same shape;

the two dipole arms are symmetrically arranged at two sides of the dielectric plate, and two dipole arm connecting points are symmetrically attached to two surfaces of the dielectric plate respectively and are used for electrically connecting the two dipole arms respectively;

the dipole arm is a hollow curved shell and comprises a vertex and a bottom surface; the outer surface of the dipole arm comprises an ellipsoid curved surface and an arc curved surface, the ellipsoid curved surface is a part of an ellipsoid which is cut along a vertical plane of the long axis, and the vertex of the ellipsoid is used as the vertex of the dipole arm; the arc-shaped curved surface is an axisymmetric curved surface and is formed by rotating a curve for a circle along the long axis of an ellipsoid, the arc-shaped curved surface comprises a first edge and a second edge, the first edge is overlapped with the section of the ellipsoid, and the plane where the second edge is located is used as the bottom surface of the dipole arm;

the top points of the two dipole arms are respectively connected with the connecting points of the two dipole arms on the dielectric plate and are used for taking the two dipole arms as broadband feed sources of the ultra-wideband dipole antenna;

the distance between the bottom surfaces of the two dipole arms is 500 mm;

the coupling branch structure comprises four coupling branches symmetrically arranged on a cylindrical surface formed by surrounding the bottom surfaces of the two dipole arms, two ends of each coupling branch are respectively connected with the bottom surfaces of the two dipole arms, and the coupling branch structure is a polygonal line structure bent by strip metal and used as a multiband source of the ultra-wideband dipole antenna.

Further, the diameter of a circle surrounded by the second edge of the arc-shaped curved surface is larger than the length of the short axis of the ellipsoid curved surface; and/or the diameter of a circle formed by the first edges of the arc-shaped curved surfaces is not more than the length of a short axis of the ellipsoid curved surface.

Furthermore, each coupling branch also comprises two branch resistors which are respectively connected in series in the middle of the coupling branch.

Further, the resistance value of the branch resistor is 65 ohms.

Further, the port resistance of both of the dipole arms is 75 ohms.

The radio frequency transformer is arranged on one surface of the medium plate in a mounting manner; the radio frequency transformer comprises an input end and an output end, the input end of the radio frequency transformer is electrically connected with the dipole arm connecting point, and the output end of the radio frequency transformer is used as the output end of the ultra-wideband dipole antenna and is connected with a coaxial cable so as to match the impedance of the coaxial cable with the impedance conversion of the dipole.

Further, the distance between the apexes of the two dipole arms was 6 mm.

Furthermore, a connection pad is disposed between the vertex of each dipole arm and the dipole arm connection point for electrically connecting the vertex of the dipole arm and the dipole arm connection point.

Furthermore, the edge of the bottom surface of each dipole arm is provided with a metal ring structure, the inner edge of the metal ring structure is superposed with the edge of the bottom surface of the dipole arm, and two ends of each coupling branch are respectively in contact connection with the two metal rings.

Further, the width of the metal ring is 5 mm.

According to the ultra-wideband dipole antenna of the embodiment, the ultra-wideband dipole antenna comprises a dielectric plate, a coupling branch structure and two dipole arms with the same shape, wherein the dipole arms are hollow curved surface shells and are symmetrically arranged by taking the dielectric plate as a central plane to serve as a broadband feed source of the dipole antenna. Wherein the curved surface of each dipole arm comprises an ellipsoid curved surface and an arc curved surface. The coupling branch structure comprises four coupling branches which are symmetrically arranged on the periphery of the two dipole arms and used as a multiband source of the dipole antenna, wherein each coupling branch is of a broken line structure formed by bending strip-shaped metal. The ultra-wideband dipole antenna disclosed by the application is applied to a low frequency band so as to solve the technical problems that an ordinary dipole antenna is large in installation size and needs multi-segment design in use.

Drawings

FIG. 1 is a schematic diagram of an ultra-wideband dipole antenna according to an embodiment;

FIG. 2 is a schematic diagram of an ultra-wideband dipole antenna according to an embodiment;

FIG. 3 is a schematic diagram of a dipole arm in one embodiment;

FIG. 4 is a schematic structural view of a dielectric plate according to an embodiment;

fig. 5 is a simulation and actual measurement comparison diagram of the ultra-wideband dipole antenna in one embodiment.

Detailed Description

The present application will be described in further detail below with reference to the accompanying drawings by way of specific embodiments. Wherein like elements in different embodiments are numbered with like associated elements. In the following description, numerous details are set forth in order to provide a better understanding of the present application. However, those skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances. In some instances, certain operations related to the present application have not been shown or described in detail in order to avoid obscuring the core of the present application from excessive description, and it is not necessary for those skilled in the art to describe these operations in detail, so that they may be fully understood from the description in the specification and the general knowledge in the art.

Furthermore, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. Also, the various steps or actions in the method descriptions may be transposed or transposed in order, as will be apparent to one of ordinary skill in the art. Thus, the various sequences in the specification and drawings are for the purpose of describing certain embodiments only and are not intended to imply a required sequence unless otherwise indicated where such sequence must be followed.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings).

Dipole antennas (Dipole antenna or doubls) are the first type of antenna used in radio communications, the simplest structure and the most widely used. The two ends of the conductors close to each other are respectively connected with a feeder line. When used as a transmitting antenna, electrical signals are fed into the conductor from the center of the antenna; when used as a receiving antenna, the received signal is also taken from the conductor at the center of the antenna. A conventional dipole antenna is formed by two coaxial straight wires, and the radiation field generated by the antenna at a far distance is axisymmetric and can be strictly solved theoretically. The dipole antenna is a resonant antenna and theoretical analysis shows that the current distribution within the elongated dipole antenna has the form of a standing wave having a wavelength that is exactly the wavelength of the electromagnetic waves generated or received by the antenna. Thus, when a dipole antenna is made, the length of the antenna is determined by the operating wavelength. The most common dipole antenna is a half-wave antenna, whose total length is approximately half the operating wavelength. In addition to half-wave antennas formed by straight wires, other types of dipole antennas are sometimes used, such as full-wave antennas, short antennas, and more complex-shaped cage antennas, batwing antennas, etc. formed by straight wires. Generally, a dipole antenna has a narrow bandwidth, and to receive a broadband radio signal, a common method is to design multiple dipoles in a frequency division band to satisfy different frequency bands, and then combine the dipoles to cover a wide frequency range. As a result, the antenna has a complicated structure and a large installation size, which limits the application of the antenna. Generally, a common dipole antenna is adopted, a frequency range of 75MHz-500MHz is covered, a good receiving effect is obtained, the installation size is estimated to reach about 2 meters, and the dipole antenna is designed in at least 2 sections.

In the embodiment of the application, the ultra-wideband dipole antenna comprises a dielectric plate, a coupling branch structure and two dipole arms with the same shape, wherein the dipole arms are hollow curved surface shells and are symmetrically arranged by taking the dielectric plate as a central plane to serve as a broadband feed source of the dipole antenna. Wherein the curved surface of each dipole arm comprises an ellipsoid curved surface and an arc curved surface. The coupling branch structure comprises four coupling branches which are symmetrically arranged on the periphery of the two dipole arms and used as a multiband source of the dipole antenna, wherein each coupling branch is of a broken line structure formed by bending strip-shaped metal. The ultra-wideband dipole antenna disclosed by the application is applied to a low frequency band so as to solve the technical problems that an ordinary dipole antenna is large in installation size and needs multi-segment design in use.

Example one

Referring to fig. 1, a schematic structural diagram of an ultra-wideband dipole antenna in an embodiment is shown, where the ultra-wideband dipole antenna includes two dipole arms 1 with the same shape, a dielectric plate 2, and a coupling branch structure 3.

Referring to fig. 2, which is a schematic structural diagram of an ultra-wideband dipole antenna in an embodiment, fig. 2(a) is a schematic structural diagram of a dipole arm 1 and a dielectric plate 2, fig. 2(c) is a schematic structural diagram of a coupling branch structure 3, two dipole arms 1 are symmetrically disposed on two sides of the dielectric plate 2, and two dipole arm connection points are symmetrically attached to two sides of the dielectric plate 2, respectively, for electrically connecting the two dipole arms 1, respectively. The coupling branch structure 3 comprises four coupling branches 31 symmetrically arranged on a cylindrical surface surrounded by the bottom surfaces of the two dipole arms 1, two ends of each coupling branch 31 are respectively connected with the bottom surfaces of the two dipole arms 1, and the coupling branch structure is a polygonal line structure bent by strip metal and used as a multiband source of the ultra-wideband dipole antenna. In one embodiment, each coupling branch 31 further includes two branch resistors 32, which are respectively connected in series to the middle of the coupling branch 31. In one embodiment, the stub resistor has a resistance of 65 ohms. In one embodiment, the edge of the bottom surface of each dipole arm 1 is provided with a metal ring structure 4, the inner edge of the metal ring structure 4 coincides with the edge of the bottom surface of the dipole arm 1, and two ends of each coupling branch 31 are respectively connected with two metal rings 4 in a contact manner. In one embodiment, the width of the metal ring 4 is 5 mm, the outer diameter of the metal ring is 150 mm, and the inner diameter of the metal ring is 140 mm.

Referring to fig. 3, which is a schematic structural diagram of a dipole arm in an embodiment, the dipole arm 1 is a hollow curved shell, and includes a vertex 12 and a bottom surface 11. The outer surface of the dipole arm 1 comprises an ellipsoid curved surface and an arc curved surface, the ellipsoid curved surface is a part of an ellipsoid which is cut along a vertical plane of a long axis, and the vertex of the ellipsoid is used as the vertex 12 of the dipole arm. The arc-shaped curved surface is an axisymmetric curved surface and is formed by rotating a curve for a circle along the long axis of the ellipsoid, the arc-shaped curved surface comprises a first edge and a second edge, the first edge is overlapped with the section of the ellipsoid, and the plane where the second edge is located is used as the bottom surface 11 of the dipole arm. The vertexes 12 of the two dipole arms 1 are respectively connected with the connecting points of the two dipole arms on the dielectric plate 2, and the two dipole arms 1 are used as a broadband feed source of the ultra-wideband dipole antenna. In one embodiment, the diameter of the circle surrounded by the second edge of the arc-shaped curved surface is larger than the length of the short axis of the ellipsoid curved surface. In one embodiment, the diameter of the circle defined by the first edges of the arc-shaped curved surfaces is not greater than the length of the short axis of the ellipsoid curved surfaces. In one embodiment, a connection pad 13 is disposed between the vertex 12 of each dipole arm 1 and the dipole arm connection point for electrically connecting the vertex 12 of the dipole arm and the dipole arm connection point. In one embodiment, the distance between the apexes 12 of the two dipole arms is 6 mm. In one embodiment, the port resistance of the two dipole arms 1 is 75 ohms. In one embodiment, the distance between the bottom surfaces of the two dipole arms 1 is 500 mm.

Referring to fig. 4, a schematic structural diagram of an embodiment of a dielectric board is shown, in which the thickness of the dielectric board is 6 mm to ensure that the distance between the vertices 12 of two dipole arms is 6 mm, and each surface of the dielectric board is provided with a dipole arm connection point 21. In an embodiment, the ultra-wideband dipole antenna further includes a radio frequency transformer 22 mounted on one surface of the dielectric plate 2, the radio frequency transformer 22 includes an input end and an output end, the input end of the radio frequency transformer 22 is used for electrically connecting with the dipole arm connection point 21, and the output end of the radio frequency transformer is used as the output end 23 of the ultra-wideband dipole antenna for connecting with a coaxial cable, so as to match the impedance of the coaxial cable with the impedance conversion of the dipole.

The ultra-wideband dipole antenna disclosed by the application consists of a bent wire and eight resistors, wherein the bent wire is used for feeding broadband and connecting a top metal ring to a bottom metal ring. The port impedance of the dipole is 75 omega, and a radio frequency transformer which is pasted on the surface of a medium plate is used for impedance matching, namely the radio frequency transformer is used as a balun for feeding from a cable to an antenna. In one embodiment, the RF transformer is of type TT1.5-1-KK81, which has low insertion loss, and converts the 50 Ω impedance of the coaxial line to 75 Ω of a dipole at a frequency in the range of 0.075-500 MHz. In the embodiment of the application, the curve cone is used as a broadband feeding strategy for feeding, so that a wide frequency range can be met by one pair of dipole antennas, the problems caused by using a common dipole antenna are solved, and the application requirements of various occasions are met. Compared with the common dipole antenna in the prior art, the maximum size is only 0.5 meter, the dipole antenna is applied to a low frequency band, the working frequency range is 75MHz-500MHz, the standing-wave ratio is less than 2.5:1, and the gain is-20 dBi when 80MHz is used.

Referring to fig. 5, which is a graph showing the comparison between the simulation and the actual measurement results of the ultra-wideband dipole antenna in one embodiment, fig. 5(a) is a graph showing the comparison between the simulation result and the actual measurement result of the VSWR of 3:1, wherein the VSWR is 2.5:1 and the actual measurement result is 80-600 MHz. Dipole diameter is 0.04 λ fmin, height is 0.13 λ fmin measured, where λ fmin is the wavelength of the lowest operating frequency signal in free space. FIG. 5(b) shows the results of the gain simulation, and the simulation tool is CSTMAWave Studio.

The present application has been described with reference to specific examples, which are provided only to aid understanding of the present application and are not intended to limit the present application. For a person skilled in the art to which the application pertains, several simple deductions, modifications or substitutions may be made according to the idea of the application.

Claims (10)

1. An ultra-wideband dipole antenna is characterized by comprising a dielectric plate, a coupling branch structure and two dipole arms with the same shape;

the two dipole arms are symmetrically arranged at two sides of the dielectric plate, and two dipole arm connecting points are symmetrically attached to two surfaces of the dielectric plate respectively and are used for electrically connecting the two dipole arms respectively;

the dipole arm is a hollow curved shell and comprises a vertex and a bottom surface; the outer surface of the dipole arm comprises an ellipsoid curved surface and an arc curved surface, the ellipsoid curved surface is a part of an ellipsoid which is cut along a vertical plane of the long axis, and the vertex of the ellipsoid is used as the vertex of the dipole arm; the arc-shaped curved surface is an axisymmetric curved surface and is formed by rotating a curve for a circle along the long axis of an ellipsoid, the arc-shaped curved surface comprises a first edge and a second edge, the first edge is overlapped with the section of the ellipsoid, and the plane where the second edge is located is used as the bottom surface of the dipole arm;

the top points of the two dipole arms are respectively connected with the connecting points of the two dipole arms on the dielectric plate and are used for taking the two dipole arms as broadband feed sources of the ultra-wideband dipole antenna;

the distance between the bottom surfaces of the two dipole arms is 500 mm;

the coupling branch structure comprises four coupling branches symmetrically arranged on a cylindrical surface formed by surrounding the bottom surfaces of the two dipole arms, two ends of each coupling branch are respectively connected with the bottom surfaces of the two dipole arms, and the coupling branch structure is a polygonal line structure bent by strip metal and used as a multiband source of the ultra-wideband dipole antenna.

2. The ultra-wideband dipole antenna of claim 1 wherein said arcuate curved second edge defines a circle having a diameter greater than a minor axis length of said elliptical curved surface; and/or the diameter of a circle formed by the first edges of the arc-shaped curved surfaces is not more than the length of a short axis of the ellipsoid curved surface.

3. The ultra-wideband dipole antenna of claim 1 wherein each of said coupling branches further comprises two branch resistors each connected in series in the middle of said coupling branch.

4. The ultra-wideband dipole antenna of claim 3 wherein said stub resistor has a resistance of 65 ohms.

5. The ultra-wideband dipole antenna of claim 1 wherein the two dipole arms have a port resistance of 75 ohms.

6. The ultra-wideband dipole antenna of claim 5 further comprising a radio frequency transformer mounted on one face of said dielectric slab; the radio frequency transformer comprises an input end and an output end, the input end of the radio frequency transformer is electrically connected with the dipole arm connecting point, and the output end of the radio frequency transformer is used as the output end of the ultra-wideband dipole antenna and is connected with a coaxial cable so as to match the impedance of the coaxial cable with the impedance conversion of the dipole.

7. The ultra-wideband dipole antenna of claim 6 wherein the distance between the apexes of said dipole arms is 6 mm.

8. The ultra-wideband dipole antenna of claim 7 and wherein a connection pad is provided between the apex of each of said dipole arms and said dipole arm connection point for electrically connecting the apex of said dipole arm to said dipole arm connection point.

9. The ultra-wideband dipole antenna of claim 1 wherein the bottom edge of each dipole arm is provided with a metal ring structure, the inner edge of the metal ring structure coincides with the bottom edge of the dipole arm, and the two ends of each coupling branch are respectively in contact connection with the two metal rings.

10. The ultra-wideband dipole antenna of claim 9, wherein said metallic loop has a width of 5 mm.

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