Omnidirectional antenna with broadband and wide axial ratio beam and communication system

Abstract

The invention discloses a broadband and wide-axial-ratio beam omnidirectional antenna and a communication system. The antenna comprises a biconical antenna, a conformal medium circular polarizer, a coaxial connector and a fixing device, the coaxial connector is connected with the biconical antenna; the fixing device is used for fixing the biconical antenna in the conformal medium circular polarizer; the polarization direction of the biconical antenna is vertically polarized; the conformal medium circular polarizer comprises a plurality of fan-blade-shaped structures, and the fan-blade-shaped structures are rotationally arranged around a central shaft. According to the embodiment of the invention, by designing the conformal dielectric circular polarizer, the linearly polarized wave can be converted into the circularly polarized wave, so that the antenna has the characteristics of a broadband and a relatively wide axial ratio beam in a millimeter wave band; and the communication effect is improved. The antenna can be widely applied to the technical field of antennas.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to an omnidirectional antenna with a broadband and wide axial ratio beam and a communication system. Background Art

[0002] Broadband circularly polarized antennas are key components in high-speed millimeter-wave communications. With the growing demand for data transmission, the application of broadband millimeter-wave technology in high-speed wireless communications has gradually become prominent. While having broad application prospects, broadband omnidirectional circularly polarized antennas with wide axial ratio beams are also difficult to achieve, especially in the millimeter-wave frequency band. The introduction of dielectric circular polarizers provides new design ideas for circularly polarized antennas, especially millimeter-wave circularly polarized antennas. Existing dielectric circular polarizers are mostly in the form of two-dimensional planes, which can perform polarization deflection in a single incident direction and do not have the characteristics of wide axial ratio beams. Summary of the invention

[0003] The purpose of the present invention is to solve one of the technical problems existing in the prior art to at least a certain extent.

[0004] To this end, an object of the present invention is to provide a high-performance broadband and wide-axis ratio beam omnidirectional antenna and communication system.

[0005] In order to achieve the above technical objectives, the technical solutions adopted by the embodiments of the present invention include the following aspects:

[0006] On the one hand, an embodiment of the present invention provides an omnidirectional antenna with a broadband and wide axial ratio beam, comprising: a biconical antenna, a conformal dielectric circular polarizer, a coaxial connector and a fixing device; the coaxial connector is connected to the biconical antenna; the fixing device is used to fix the biconical antenna in the conformal dielectric circular polarizer; the polarization direction of the biconical antenna presents vertical polarization; the conformal dielectric circular polarizer includes a plurality of fan-shaped structures, and the fan-shaped structures are arranged in a rotation around a central axis. The embodiment of the present application can convert linearly polarized waves into circularly polarized waves by designing a conformal dielectric circular polarizer, so that the antenna has broadband and wider axial ratio beam characteristics in the millimeter wave band, thereby improving the communication effect.

[0007] In addition, the broadband and wide-axis ratio beam omnidirectional antenna according to the above embodiment of the present invention may also have the following additional technical features:

[0008] Furthermore, in the broadband and wide axial ratio beam omnidirectional antenna of the embodiment of the present invention, the angle between any point on the tangent curve of the conformal dielectric circular polarizer and the direction of the incident ray polarization electric field is 45°.

[0009] Further, in one embodiment of the present invention, the electric field of the incident linear polarized wave is divided into a first component and a second component:

[0010] ε|| =p×ε1+(1-p)×ε0;

[0011]

[0012] Among them, ε || is the first dielectric constant associated with the first component, ε ⊥ is the second dielectric constant related to the second component, p is the content ratio of the dielectric material in the conformal dielectric circular polarizer, p=W1 / (W0+W1); W0 is the width of the air layer in the conformal dielectric circular polarizer, W1 is the width of the dielectric material in the conformal dielectric circular polarizer; ε1 is the relative dielectric constant of the dielectric material, and ε0 is the relative dielectric constant of air.

[0013] Furthermore, in one embodiment of the present invention, if the phase difference between the first component and the second component reaches 90°, the transmitted wave is converted from a linearly polarized wave to a circularly polarized wave after passing through the conformal dielectric circular polarizer; if W0 and W1 are small enough, the polarization conversion effect is related to the dielectric constant of the dielectric material and the content ratio of the dielectric material.

[0014] Furthermore, in one embodiment of the present invention, the conformal dielectric circular polarizer is:

[0015]

[0016] Among them, (P x ,P y ,P z ) is the medium of the conformal dielectric circular polarizer, [S] is the polarizer surface of the conformal dielectric circular polarizer for left-handed rotation, [S'] is the polarizer surface of the conformal dielectric circular polarizer for right-handed rotation, [R] is the sweep factor of [S] around the z-axis, P N is the number of conformal dielectric polarizers uniformly distributed along the rotation axis, r is the spherical radius of the conformal dielectric circular polarizer, is the angle between the horizontal projection of the orientation curve of the conformal dielectric circular polarizer in spherical coordinates and the x-axis, and θ is the angle between the vertical projection of the orientation curve of the conformal dielectric circular polarizer in spherical coordinates and the z-axis.

[0017] Furthermore, in one embodiment of the present invention, in any cross-section of the conformal dielectric circular polarizer, the dielectric sheet and the air maintain a preset ratio; in the radial direction of the conformal dielectric circular polarizer, incident waves at different angles maintain a consistent propagation path length in the conformal dielectric circular polarizer.

[0018] Further, in one embodiment of the present invention, the antenna further comprises: a first impedance matching layer and a second impedance matching layer;

[0019] The first impedance matching layer is adjacent to the inner surface of the conformal dielectric circular polarizer, and the second impedance matching layer is adjacent to the outer surface of the conformal dielectric circular polarizer; both the first impedance matching layer and the second impedance matching layer are mesh structures.

[0020] Further, in one embodiment of the present invention, the first impedance matching layer or the second impedance matching layer is:

[0021]

[0022] Where p' is the content ratio of the dielectric material in the impedance matching layer, (P x ”,P y ”,P z ”) is the dielectric part of the impedance matching layer, [S] is the polarizer surface of the left-handed conformal dielectric circular polarizer, [S'] is the polarizer surface of the right-handed conformal dielectric circular polarizer, [R] is the sweep factor of [S] around the z-axis, P N '=P N / n,P N is the number of conformal dielectric polarizers uniformly distributed along the rotation axis, n is a positive integer, r is the spherical radius of the conformal dielectric circular polarizer, is the angle between the horizontal projection of the orientation curve of the conformal dielectric circular polarizer in spherical coordinates and the x-axis, and θ is the angle between the vertical projection of the orientation curve of the conformal dielectric circular polarizer in spherical coordinates and the z-axis.

[0023] On the other hand, an embodiment of the present invention provides a radar system, comprising the above-mentioned omnidirectional antenna with broadband and wide axial ratio beam.

[0024] On the other hand, an embodiment of the present invention provides a communication system, including the above-mentioned omnidirectional antenna with broadband and wide axial ratio beam.

[0025] The antenna provided by the embodiment of the present invention includes: a biconical antenna, a conformal dielectric circular polarizer, a coaxial connector and a fixing device; the coaxial connector is connected to the biconical antenna; the fixing device is used to fix the biconical antenna in the conformal dielectric circular polarizer; the polarization direction of the biconical antenna presents vertical polarization; the conformal dielectric circular polarizer includes a plurality of fan-shaped structures, and the fan-shaped structures are arranged in a rotation around the central axis. The embodiment of the present application can convert linearly polarized waves into circularly polarized waves by designing a conformal dielectric circular polarizer, so that the antenna has broadband and wider axial ratio beam characteristics in the millimeter wave band, thereby improving the communication effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the embodiments of the present invention or the drawings of related technical solutions in the prior art are introduced below. It should be understood that the drawings introduced below are only for the convenience of clearly describing some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A schematic structural diagram of an embodiment of an omnidirectional antenna with a broadband and wide axial ratio beam provided by the present invention;

[0028] Figure 2 A front cross-sectional schematic diagram of an embodiment of an omnidirectional antenna with a broadband and wide axial ratio beam provided by the present invention;

[0029] Figure 3 A schematic diagram of the geometric structure of a planar artificial anisotropic polarizer provided by the present invention;

[0030] Figure 4 A schematic diagram of orientation line selection of an embodiment of a polarizer provided by the present invention;

[0031] Figure 5 A schematic structural diagram of an embodiment of the sweep factor of the polarizer surface provided by the present invention;

[0032] Figure 6 for Figure 1 A schematic diagram of reflection coefficient and axial ratio of the embodiment shown;

[0033] Figure 7 for Figure 1 A schematic diagram of a gain curve of the embodiment shown;

[0034] Figure 8 for Figure 1 The schematic diagram of the shaft ratio variation of the embodiment shown;

[0035] Fig. 9 A schematic structural diagram of another embodiment of an omnidirectional antenna with a broadband and wide axial ratio beam provided by the present invention;

[0036] Fig.10 for Fig. 9 A schematic front cross-sectional view of the embodiment shown;

[0037] Fig.11 for Fig. 9 A schematic diagram of reflection coefficient and axial ratio of the embodiment shown;

[0038] Fig.12 for Fig. 9 A schematic diagram of a gain curve of the embodiment shown;

[0039] Fig.13 for Fig. 9 Schematic diagram of the axis ratio change of the embodiment shown. DETAILED DESCRIPTION

[0040] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to be construed as limitations of the present invention. For the step numbers in the following embodiments, they are only provided for the convenience of explanation, and the order between the steps is not limited in any way, and the execution order of each step in the embodiment can be adaptively adjusted according to the understanding of those skilled in the art.

[0041] First, the terms involved in the embodiments of the present application are explained:

[0042] Polarization: It is the characteristic that the orientation of the electric field intensity vector at a given point in space changes with time.

[0043] Linearly polarized wave: The two components of the electric field vector (denoted as x component and y component) are in phase with each other or differ by π, that is, Or ±π, the composite wave is called a linearly polarized wave.

[0044] Circularly Polarized Wave: The two components of the electric field vector (denoted as x-component and y-component) have equal amplitudes and a phase difference. That is E xm =E ym =E m , When , the composite wave is called a circularly polarized wave.

[0045] Polarization Mismatch: The phenomenon caused by the polarization of the receiving antenna being inconsistent with the polarization of the incident plane wave.

[0046] Multipath Effect: refers to the situation where, after electromagnetic waves propagate through different paths, each component field arrives at the receiving end at different times, and the components overlap with each other according to their respective phases, causing interference, distorting the original signal, or generating errors.

[0047] Omnidirectional: The horizontal radiation pattern shows uniform radiation at 360°, and the vertical radiation pattern shows a beam with a certain width.

[0048] Axial Ratio: The ratio of the major axis to the minor axis of the polarization ellipse.

[0049] Axial-ratio Beamwidth: The angular range in which the axial ratio is less than 3dB in the electromagnetic beam radiated in a specific direction by the antenna

[0050] Circularly polarized waves are a promising solution to many electromagnetic wave propagation problems in existing wireless communication systems. Compared with linearly polarized waves, circularly polarized waves can effectively solve problems such as polarization mismatch and multi-path effect in the process of electromagnetic wave transmission and reception, thereby greatly improving signal quality. In addition, in radar systems, circularly polarized antennas that can transmit and receive circularly polarized waves can provide more polarization scattering information, which significantly improves the accuracy of target recognition. Omnidirectional circularly polarized antennas are a special type of circularly polarized antennas that have the characteristics of circular polarization and omnidirectional radiation. They can stably transmit signals in systems with uncertain motion trajectories such as telemetry, remote sensing, positioning and navigation, and need to communicate in motion. They are widely used in vehicle-mounted, airborne and ship-mounted scenarios.

[0051] Wideband circularly polarized antennas are key components in high-speed millimeter wave communications. With the growing demand for data transmission, the application of broadband millimeter wave technology in high-speed wireless communications has gradually become prominent. The rich spectrum resources in the millimeter wave band can solve the problem of tight electromagnetic spectrum resources in the microwave band in current wireless communications, making large-capacity and high-speed data transmission possible. Wide axial ratio beamwidth is a higher requirement for broadband omnidirectional circularly polarized antennas. Broadband omnidirectional circularly polarized antennas only require the antenna to have a high axial ratio bandwidth at a certain elevation angle (generally the elevation angle corresponding to the maximum radiation direction), while broadband omnidirectional circularly polarized antennas with wide axial ratio beams require a high axial ratio bandwidth within a large elevation angle range, and have the advantages of high bandwidth and wide coverage. They are ideal RF devices in millimeter wave wireless communication systems. While having broad application prospects, broadband omnidirectional circularly polarized antennas with wide axial ratio beams are also difficult to achieve, especially in the millimeter wave frequency band.

[0052] The introduction of dielectric circular polarizers provides a new design idea for circularly polarized antennas, especially millimeter-wave circularly polarized antennas. Existing dielectric circular polarizers are mostly in the form of two-dimensional planes, which can perform polarization deflection in a single incident direction and do not have wide axial ratio beam characteristics. There are currently no literature reports on broadband conformal dielectric circular polarizers or broadband millimeter-wave omnidirectional circularly polarized antennas with wide axial ratio beam characteristics. Based on the above problems, the present invention proposes a broadband, wide axial ratio beam, millimeter-wave omnidirectional circularly polarized antenna.

[0053] The following describes in detail an omnidirectional antenna with a wide bandwidth and a wide axial ratio beam and a communication system according to an embodiment of the present invention with reference to the accompanying drawings. First, an omnidirectional antenna with a wide bandwidth and a wide axial ratio beam according to an embodiment of the present invention is described with reference to the accompanying drawings.

[0054] Figure 1 1 is a schematic diagram of a broadband and wide-axis ratio beam omnidirectional antenna structure according to an embodiment of the present invention. The system specifically includes:

[0055] Biconical antennas, conformal dielectric circular polarizers, coaxial connectors and fixtures;

[0056] The coaxial connector is connected to the biconical antenna; the fixing device is used to fix the biconical antenna in the conformal dielectric circular polarizer; the polarization direction of the biconical antenna presents vertical polarization;

[0057] The conformal dielectric circular polarizer includes a plurality of fan-blade structures, and the fan-blade structures are arranged in a rotational manner around a central axis.

[0058] Reference Figure 1 As shown, the biconical antenna in the embodiment of the present application is coaxially connected to the coaxial connector and fixed inside the conformal dielectric circular polarizer by a fixing device. In some embodiments, the fixing device includes an upper and lower part for fixing the biconical antenna and the coaxial connector. The structure of the conformal dielectric circular polarizer is shown in FIG. Figure 1 As shown, it is composed of a plurality of fan-like structures rotating to form two surfaces, an inner surface and an outer surface.

[0059] Optionally, in the broadband and wide axial ratio beam omnidirectional antenna in the embodiment of the present invention, the angle between any point on the tangent curve of the conformal dielectric circular polarizer and the direction of the incident ray polarization electric field is 45°.

[0060] Optionally, the electric field of the incident line polarized wave of the broadband and wide axial ratio beam omnidirectional antenna in the embodiment of the present invention is divided into a first component and a second component:

[0061] ε || =p×ε1+(1-p)×ε0;

[0062]

[0063] Among them, ε || is the first dielectric constant associated with the first component, ε ⊥ is the second dielectric constant related to the second component, p is the content ratio of the dielectric material in the conformal dielectric circular polarizer, p=W1 / (W0+W1); W0 is the width of the air layer in the conformal dielectric circular polarizer, W1 is the width of the dielectric material in the conformal dielectric circular polarizer; ε1 is the relative dielectric constant of the dielectric material, and ε0 is the relative dielectric constant of air.

[0064] Optionally, for the omnidirectional antenna with broadband and wide axial ratio beam in an embodiment of the present invention, if the phase difference between the first component and the second component reaches 90°, the transmitted wave is converted from a linearly polarized wave to a circularly polarized wave after passing through the conformal dielectric circular polarizer; if W0 and W1 are small enough, the polarization conversion effect is related to the dielectric constant of the dielectric material and the content ratio of the dielectric material.

[0065] Optionally, in the broadband and wide-axis ratio beam omnidirectional antenna in the embodiment of the present invention, the conformal dielectric circular polarizer is:

[0066]

[0067] Among them, (P x ,P y ,P z ) is the medium of the conformal dielectric circular polarizer, [S] is the polarizer surface of the conformal dielectric circular polarizer for left-handed rotation, [S'] is the polarizer surface of the conformal dielectric circular polarizer for right-handed rotation, [R] is the sweep factor of [S] around the z-axis, P N is the number of conformal dielectric polarizers uniformly distributed along the rotation axis, r is the spherical radius of the conformal dielectric circular polarizer, is the angle between the horizontal projection of the orientation curve of the conformal dielectric circular polarizer in spherical coordinates and the x-axis, and θ is the angle between the vertical projection of the orientation curve of the conformal dielectric circular polarizer in spherical coordinates and the z-axis. p is the content ratio of the dielectric material in the conformal dielectric circular polarizer. It can be understood that when the design of the conformal dielectric circular polarizer is right-handed circular polarization, the surface of the polarizer is represented by [S']; when the design of the conformal dielectric circular polarizer is left-handed circular polarization, the surface of the polarizer is represented by [S].

[0068] Optionally, in the broadband and wide axial ratio beam omnidirectional antenna in the embodiment of the present invention, in any cross-section of the conformal dielectric circular polarizer, the dielectric sheet and the air maintain a preset ratio; in the radial direction of the conformal dielectric circular polarizer, incident waves at different angles maintain a consistent propagation path length in the conformal dielectric circular polarizer.

[0069] The omnidirectional antenna proposed in the present application is introduced in detail with a specific embodiment below, which specifically includes: a biconical antenna, a conformal dielectric circular polarizer, a coaxial connector and a fixing device. The conformal dielectric circular polarizer is composed of a plurality of fan-shaped structures. These fan-shaped structures rotate around the central axis to form a conformal dielectric circular polarizer. In some embodiments, the conformal dielectric circular polarizer can be prepared using a transparent photosensitive resin material, specifically, it can be printed by 3D printing technology. The biconical antenna and the coaxial connector are both placed in the conformal dielectric circular polarizer, and the polarization direction of the biconical antenna is vertically polarized. Two fixing devices are respectively arranged above and below the conformal dielectric circular polarizer to fix the biconical antenna in the polarizer. The fixing device is also used to fix the conformal dielectric circular polarizer. In this way, omnidirectional performance of broadband and wide axial ratio beams is achieved. Among them, the principle of the conformal dielectric circular polarizer is as follows:

[0070] Due to the artificial anisotropic material properties of the periodic dielectric sheet, the conformal dielectric circular polarizer requires that the tangent direction of the dielectric sheet maintain a 45° angle with the direction of the incident line polarization electric field at all positions. Therefore, any point on the tangent curve of the conformal dielectric circular polarizer needs to have a 45° angle with the direction of the incident line polarization electric field. When the electric field E of the incident line polarization wave is 45° to the direction of the dielectric sheet, the electric field can be divided into two orthogonal components, namely E and || and E ⊥ , the amplitude and phase of these two components are equal. Due to the anisotropy of the material, E || and E ⊥ With different equivalent dielectric constants ε || and ε ⊥ Related, ε || and ε ⊥ The formula is as follows:

[0071] ε || =p×ε1+(1-p)×ε0;

[0072]

[0073] Where p is the content ratio of the dielectric material in the conformal dielectric circular polarizer (p = W1 / (W0+W1)), ε1 and ε0 are the relative dielectric constants of the dielectric material and air, respectively. W0 is the width of the air layer in the conformal dielectric circular polarizer; W1 is the width of the dielectric material in the conformal dielectric circular polarizer; W0 and W1 can be Figure 3See the specific meaning. ε0 is the relative dielectric constant of air; ε1 is the relative dielectric constant of dielectric material. Due to the different propagation speeds, when the phase difference between the two orthogonal electric field components reaches 90°, the linear polarization wave is transformed into a circular polarization wave after the transmitted wave passes through the circular polarizer. When W1 and W0 are small enough, the polarization conversion effect is only related to the dielectric constant of the dielectric material and the content ratio p of the dielectric material in the circular polarizer.

[0074] Planar anisotropic polarizers work under the assumption that the incident linearly polarized wave has a plane wavefront. Antennas using plane anisotropic polarizers have a unidirectional radiation pattern. In order to obtain omnidirectional circularly polarized radiation, the direction of the polarizer follows the orientation curve of the polarizer, that is, (P x ',P y ',P z ') curve. It can be understood that the orientation curve is a curve for designing the shape of the dielectric sheet (fan-shaped) in the conformal dielectric circular polarizer, and this curve can well explain the design principle of the dielectric circular polarizer. Since the orientation curve at each point should be at an angle of 45° with the incident electric field, it can be obtained:

[0075]

[0076] Then we have:

[0077]

[0078] The dielectric part of the conformal dielectric circular polarizer that generates omnidirectional circularly polarized waves is (P x ,P y ,P z ) indicates that the conformal dielectric circular polarizer can be expressed as:

[0079]

[0080] Where [S] represents the polarizer surface of the left-handed circular polarizer, and [R] is the sweep factor of the surface [S] around the z-axis (Sweeping Factor: a common concept in 3D CAD, meaning moving a 2D surface along a path to form a 3D entity through an area). N is the number of conformal dielectric polarizers uniformly distributed along the rotation axis. r is the spherical radius of the conformal dielectric circular polarizer; is the angle between the horizontal projection of the orientation curve of the conformal dielectric circular polarizer in spherical coordinates and the x-axis; θ is the angle between the vertical projection of the orientation curve of the conformal dielectric circular polarizer in spherical coordinates and the z-axis; the meanings of the above parameters can be obtained from Figure 4 It should be noted that asinh is a trigonometric function, namely the inverse hyperbolic sine.

[0081] In order to achieve the polarization deflection effect of a wide axial ratio beam, the three-dimensional model of the conformal dielectric circular polarizer has similar design requirements to the planar dielectric circular polarizer: in any cross-section of the circular polarizer, the dielectric sheet and the air need to maintain a certain ratio (that is, p needs to maintain a certain ratio); in the radial direction of the circular polarizer, the propagation path length of incident waves at different angles in the circular polarizer needs to be consistent.

[0082] The above inferences can lead to the design of the conformal dielectric circular polarizer. The vertically polarized biconical antenna is placed so that the incident polarized wave of the antenna forms an angle of 45° with the tangent direction of the conformal dielectric circular polarizer, thereby converting the linear polarization wave into a circular polarization wave.

[0083] The beneficial effect of this embodiment is that the omnidirectional antenna has broadband and wide axial ratio beam characteristics in the millimeter wave band. Figure 1 , 2 The figure shows the cross-sectional view and front cross-sectional view of the antenna design without impedance matching layer. The design consists of a biconical antenna, a conformal dielectric circular polarizer, a coaxial connector and a fixture. The biconical antenna is placed so that the incident polarized electric field is at a 45° angle to the tangent direction of the conformal dielectric circular polarizer.

[0084] like Figure 3 , Figure 4 , Figure 5 Shown is the schematic diagram of the design of a conformal dielectric circular polarizer.

[0085] like Figure 6 As shown, it is the reflection coefficient and axial ratio diagram of the antenna design without loaded impedance matching layer. It can be seen from the figure that the antenna design achieves the performance of working in 24GHz-33.3GHz, and the axial ratio bandwidth ranges from 26.21GHz to 34.34GHz, and the relative bandwidth is about 26.42%.

[0086] like Figure 7 As shown, it is a gain curve diagram of the antenna design. The gain of the antenna is greater than 1dB in the entire working bandwidth.

[0087] like Figure 8 As shown, the axial ratio of the antenna design without an impedance matching layer varies with θ at 27 GHz, 30 GHz, and 33 GHz. It can be concluded from the figure that the simulated axial ratio beamwidth is approximately 30° at 27 GHz to 33 GHz.

[0088] In some other embodiments, the broadband and wide axial ratio beam omnidirectional antenna in the embodiments of the present invention further comprises: a first impedance matching layer and a second impedance matching layer;

[0089] The first impedance matching layer is adjacent to the inner surface of the conformal dielectric circular polarizer, and the second impedance matching layer is adjacent to the outer surface of the conformal dielectric circular polarizer; both the first impedance matching layer and the second impedance matching layer are mesh structures.

[0090] Optionally, in the broadband and wide-axis ratio beam omnidirectional antenna in the embodiment of the present invention, the conformal dielectric circular polarizer is:

[0091]

[0092] Where p' is the content ratio of the dielectric material in the impedance matching layer, (P x ”,P y ”,P z ”) is the dielectric part of the impedance matching layer, [S] is the polarizer surface of the left-handed conformal dielectric circular polarizer, [S'] is the polarizer surface of the right-handed conformal dielectric circular polarizer, [R] is the sweep factor of [S] around the z-axis, P N '=P N / n,P N is the number of conformal dielectric polarizers uniformly distributed along the rotation axis, r is the spherical radius of the conformal dielectric circular polarizer, is the angle between the horizontal projection of the orientation curve of the conformal dielectric circular polarizer in spherical coordinates and the x-axis, and θ is the angle between the vertical projection of the orientation curve of the conformal dielectric circular polarizer in spherical coordinates and the z-axis.

[0093] The omnidirectional antenna proposed in the present application is introduced in detail below with another specific embodiment, which specifically includes: a biconical antenna, a conformal dielectric circular polarizer, a coaxial connector, two layers of impedance matching layers and a fixing device. The conformal dielectric circular polarizer is composed of a plurality of fan-shaped structures. These fan-shaped structures rotate around the central axis to form a conformal dielectric circular polarizer. Both layers of impedance matching layers are mesh-shaped, and one layer of impedance matching layer is in close contact with the outer surface of the conformal dielectric circular polarizer, and the other layer of impedance matching layer is in close contact with the inner surface of the conformal dielectric circular polarizer. In this way, better impedance matching than Example 1 can be achieved, and the overall axial ratio beam width can be improved. The biconical antenna and the coaxial connector are both placed in the conformal dielectric circular polarizer, and the polarization direction of the biconical antenna is vertically polarized. The fixing device is used to fix the biconical antenna, the conformal dielectric circular polarizer and the impedance matching layer. The principle of the impedance matching layer is as follows:

[0094] When the electric field E of the incident linear polarization wave is 45° to the direction of the dielectric plate, the electric field can be divided into two orthogonal components, namely E || and E ⊥ , the amplitude and phase of these two components are equal. Due to the anisotropy of the material, E || and E ⊥With different equivalent dielectric constants ε || and ε ⊥ Related, ε || and ε ⊥ The formula is as follows:

[0095] ε || =p'×ε1+(1-p')×ε0;

[0096]

[0097] The dielectric part of the impedance matching layer is (P x ”,P y ”,P z ”) is as follows:

[0098]

[0099]

[0100] Where p' is the content ratio of the dielectric material in the impedance matching layer, [S] and [S'] represent the polarizer surface of the left-handed and right-handed circular polarizers, respectively, [R] is the sweeping factor of the polarizer surface around the z-axis, and P N '=P N / n,P N is the number of conformal dielectric polarization sheets uniformly distributed along the rotation axis, and n is a positive integer.

[0101] The design of the impedance matching layer can be obtained through the above principle. The impedance matching layer can achieve good impedance matching at 24GHz-36GHz without affecting the performance of the conformal dielectric circular polarizer, and broaden the axial ratio beamwidth of the antenna design. This omnidirectional antenna has broadband and wider axial ratio beam characteristics in the millimeter wave band and achieves better impedance matching.

[0102] like Fig. 9 , 10 The following are the cross-sectional view and front cross-sectional view of the antenna design with impedance matching layer. Figure 1 , 2 Based on the antenna design shown, impedance matching layers are loaded on the outer and inner surfaces of the conformal dielectric circular polarizer, and the placement of the biconical antenna is also required to make the incident polarized electric field form a 45° angle with the tangential direction of the conformal dielectric circular polarizer.

[0103] like Fig.11As shown, it is a reflection coefficient and axial ratio diagram of the antenna design loaded with an impedance matching layer. It can be seen from the figure that the working bandwidth of the antenna design is 24-36 GHz, and the axial ratio relative bandwidth is 26.58% (26.69 GHz-34.87 GHz).

[0104] like Fig.12 As shown, it is a gain curve diagram of the antenna design. The gain of the antenna is greater than 1dB in the entire working bandwidth.

[0105] like Fig.13 As shown, the axial ratio of the antenna designed with an impedance matching layer varies with θ at 27 GHz, 30 GHz, and 33 GHz. It can be concluded from the figure that the simulated axial ratio beamwidth is approximately 60° at 27 GHz to 33 GHz (from θ = 60° to θ = 120° or θ = -60° to θ = -120°).

[0106] The beneficial effects of the present invention are as follows: by designing a conformal dielectric circular polarizer, the linear polarization of the vertically polarized biconical antenna is converted into circular polarization performance after passing through the circular polarizer, and a wide-axis ratio beam and broadband omnidirectional antenna is realized; by designing impedance matching layers on the inner and outer surfaces of the conformal dielectric circular polarizer, the axial ratio beam width and good impedance matching of the antenna design are significantly widened, and an omnidirectional antenna with a better wide-axis ratio beam and broadband performance is realized.

[0107] On the other hand, an embodiment of the present invention provides a radar system, comprising the above-mentioned omnidirectional antenna with broadband and wide axial ratio beam.

[0108] On the other hand, an embodiment of the present invention provides a communication system, including the above-mentioned omnidirectional antenna with broadband and wide axial ratio beam.

[0109] The contents of the above antenna embodiments are all applicable to the system embodiments. The functions specifically implemented by the system embodiments are the same as those of the above antenna embodiments, and the beneficial effects achieved are also the same as those achieved by the above antenna embodiments.

[0110] In some selectable embodiments, the function / operation mentioned in the block diagram may not occur in the order mentioned in the operation diagram. For example, depending on the function / operation involved, the two boxes shown in succession can actually be executed substantially simultaneously or the boxes can sometimes be executed in reverse order. In addition, the embodiment presented and described in the flow chart of the present invention is provided by way of example, for the purpose of providing a more comprehensive understanding of technology. The disclosed method is not limited to the operation and logic flow presented herein. Selectable embodiments are expected, wherein the order of various operations is changed and the sub-operation of a part for which is described as a larger operation is performed independently.

[0111] In addition, although the present invention is described in the context of functional modules, it should be understood that, unless otherwise specified, one or more of the functions and / or features can be integrated into a single physical device and / or software module, or one or more functions and / or features can be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding the present invention. More specifically, in view of the properties, functions and internal relationships of the various functional modules in the device disclosed herein, the actual implementation of the module will be understood within the conventional skills of the engineer. Therefore, those skilled in the art can implement the present invention set forth in the claims without excessive experimentation using ordinary techniques. It is also understood that the specific concepts disclosed are merely illustrative and are not intended to limit the scope of the present invention, which is determined by the full scope of the appended claims and their equivalents.

[0112] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several programs to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0113] The logic and / or steps represented in the flowchart or otherwise described herein, for example, may be considered as an ordered list of executable programs for implementing the logical functions, and may be embodied in any computer-readable medium for use by a program execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch and execute a program from a program execution system, device or apparatus), or in conjunction with such program execution systems, devices or apparatuses. For purposes of this specification, a "computer-readable medium" may be any device that can contain, store, communicate, propagate or transmit a program for use by a program execution system, device or apparatus, or in conjunction with such program execution systems, devices or apparatuses.

[0114] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0115] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable program execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0116] In the above description of this specification, the description with reference to the terms "one embodiment / example", "another embodiment / example" or "certain embodiments / examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0117] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

[0118] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. An omnidirectional antenna with a broadband and wide axial ratio beam, characterized in that: include: Biconical antennas, conformal dielectric circular polarizers, coaxial connectors and fixtures; The coaxial connector is connected to the biconical antenna; The fixing device is used to fix the biconical antenna in the conformal dielectric circular polarizer; the polarization direction of the biconical antenna presents vertical polarization; The conformal dielectric circular polarizer includes a plurality of fan-blade structures, and the fan-blade structures are arranged in a rotational manner around a central axis.

2. The broadband and wide-axis ratio beam omnidirectional antenna according to claim 1, characterized in that: The angle between any point on the tangent curve of the conformal dielectric circular polarizer and the direction of the incident line polarization electric field is 45°.

3. The broadband and wide-axis ratio beam omnidirectional antenna according to claim 1, characterized in that: The electric field of the incident linearly polarized wave is divided into the first component and the second component: e || =p×ε1+(1-p)×ε0; Among them, ε || is the first dielectric constant associated with the first component, ε ⊥ is the second dielectric constant related to the second component, p is the content ratio of the dielectric material in the conformal dielectric circular polarizer, p=W1 / (W0+W1); W0 is the width of the air layer in the conformal dielectric circular polarizer, W1 is the width of the dielectric material in the conformal dielectric circular polarizer; ε1 is the relative dielectric constant of the dielectric material, and ε0 is the relative dielectric constant of air.

4. The broadband and wide-axis ratio beam omnidirectional antenna according to claim 3, characterized in that: If the phase difference between the first component and the second component reaches 90°, the transmitted wave is converted from a linearly polarized wave to a circularly polarized wave after passing through the conformal dielectric circular polarizer; if W0 and W1 are small enough, the polarization conversion effect is related to the dielectric constant of the dielectric material and the content ratio of the dielectric material.

5. The broadband and wide-axis-ratio beam omnidirectional antenna according to claim 1, characterized in that: The conformal dielectric circular polarizer is: Among them, (P x ,P y ,P z ) is the medium of the conformal dielectric circular polarizer, [S] is the polarizer surface of the conformal dielectric circular polarizer for left-handed rotation, [S'] is the polarizer surface of the conformal dielectric circular polarizer for right-handed rotation, [R] is the sweep factor of [S] around the z-axis, P N is the number of conformal dielectric polarizers uniformly distributed along the rotation axis, r is the spherical radius of the conformal dielectric circular polarizer, is the angle between the horizontal projection of the orientation curve of the conformal dielectric circular polarizer in spherical coordinates and the x-axis, and θ is the angle between the vertical projection of the orientation curve of the conformal dielectric circular polarizer in spherical coordinates and the z-axis.

6. The broadband and wide-axis ratio beam omnidirectional antenna according to claim 1, characterized in that: In any cross-section of the conformal dielectric circular polarizer, the dielectric sheet and the air maintain a preset ratio; in the radial direction of the conformal dielectric circular polarizer, incident waves at different angles maintain a consistent propagation path length in the conformal dielectric circular polarizer.

7. The omnidirectional antenna with a broadband and wide axial ratio beam according to claim 1, characterized in that: The antenna further comprises: a first impedance matching layer and a second impedance matching layer; The first impedance matching layer is adjacent to the inner surface of the conformal dielectric circular polarizer, and the second impedance matching layer is adjacent to the outer surface of the conformal dielectric circular polarizer; both the first impedance matching layer and the second impedance matching layer are mesh structures.

8. The omnidirectional antenna with a broadband and wide axial ratio beam according to claim 7, characterized in that: The first impedance matching layer or the second impedance matching layer is: Where p' is the content ratio of the dielectric material in the impedance matching layer, (P x ”,P y ”,P z ”) is the dielectric part of the impedance matching layer, [S] is the polarizer surface of the left-handed conformal dielectric circular polarizer, [S'] is the polarizer surface of the right-handed conformal dielectric circular polarizer, [R] is the sweep factor of [S] around the z-axis, P N '=P N / n,P N is the number of conformal dielectric polarizers uniformly distributed along the rotation axis, n is a positive integer, r is the spherical radius of the conformal dielectric circular polarizer, is the angle between the horizontal projection of the orientation curve of the conformal dielectric circular polarizer in spherical coordinates and the x-axis, and θ is the angle between the vertical projection of the orientation curve of the conformal dielectric circular polarizer in spherical coordinates and the z-axis.

9. A radar system, characterized in that: An omnidirectional antenna comprising a broadband and wide axial ratio beam as claimed in any one of claims 1 to 8.

10. A communication system, characterized in that: An omnidirectional antenna comprising a broadband and wide axial ratio beam as claimed in any one of claims 1 to 8.

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