A broadband horizontally polarized fan-shaped omni-directional antenna

Abstract

The application discloses a wideband horizontal polarization fan-arc omnidirectional antenna, which comprises an antenna substrate, a first fan-arc array, a second fan-arc array, a third fan-arc array, a fourth fan-arc array and a ground layer are etched on the antenna substrate, the first fan-arc array, the second fan-arc array, the third fan-arc array, the fourth fan-arc array and the ground layer are etched on one side of the antenna substrate by light drawing technology, and the antenna substrate is one of FR board and polytetrafluoroethylene board. The wideband horizontal polarization fan-arc omnidirectional antenna has the advantages that a fan and an arc are combined to form an array, four arc fan oscillators are uniformly arranged on a circumference, the width of the fan-arc array arm and the distance between the arc fan arrays are continuously optimized in HFSS software, the distance from the center of the fan-arc array to the center of the circle has good performance indexes, and the difficulties that the standing wave bandwidth and the directional diagram bandwidth of the conventional horizontal polarization antenna are very narrow are solved.

Description

Technical Field

[0001] This invention relates to the field of antennas, and in particular to a broadband horizontally polarized fan-shaped omnidirectional antenna. Background Technology

[0002] A broadband horizontally polarized fan-arc omnidirectional antenna is a supporting device for mobile communication. With the development of mobile communication, the bandwidth of antennas is required to be wider and wider in order to effectively integrate and utilize existing resources. At the same time, in order to reduce operating costs and increase system capacity, the traditional omnidirectional antenna only has one polarization: vertical polarization. This is obviously no longer able to meet the current communication requirements. Therefore, in many cases, it is necessary to add another polarization to the omnidirectional antenna: horizontal polarization. With the continuous development of technology, people have increasingly higher requirements for the manufacturing process of broadband horizontally polarized fan-arc omnidirectional antennas.

[0003] Existing broadband horizontally polarized fan-arc omnidirectional antennas have certain drawbacks in use. First, the antenna's standing wave bandwidth is relatively narrow, with a standing wave ratio below 1.5, meaning the actual standing wave bandwidth is only about 10%. Although parasitic patches are sometimes added near the antenna to widen this bandwidth, the widening effect is not significant, only about 2%, which is not conducive to user experience. In addition, the antenna's radiation pattern bandwidth is also relatively narrow, mainly reflected in the significant changes in cross-polarization and non-circularity with frequency, especially at high frequencies, where the antenna's axial cross-polarization is often less than -8dB and the non-circularity is less than ±4dB, which brings certain adverse effects to the user experience. To address these issues, we propose a broadband horizontally polarized fan-arc omnidirectional antenna. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a broadband horizontally polarized fan-arc omnidirectional antenna. It employs a combination of fan and arc shapes to form an array, with four arc-shaped fan elements evenly placed on the circumference. By continuously optimizing the width of the fan-arc array arm and the distance between the arc-shaped fan elements in HFSS software, excellent performance indicators are achieved for the distance from the center of the fan-arc array to the center of the circle. This solves the problem of narrow VSWR bandwidth and radiation pattern bandwidth in conventional horizontally polarized antennas, effectively addressing the issues in the background technology.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a broadband horizontally polarized fan-shaped omnidirectional antenna, comprising an antenna substrate, wherein a first fan-shaped array, a second fan-shaped array, a third fan-shaped array, a fourth fan-shaped array, and a ground layer are etched on the antenna substrate. The first fan-shaped array, the second fan-shaped array, the third fan-shaped array, the fourth fan-shaped array, and the ground layer are etched on one side of the antenna substrate using photoplotting technology. The antenna substrate is either an FR plate or a polytetrafluoroethylene plate. The other side of the antenna substrate is etched with a conventional feed coupling balun and a 1-to-4 splitter network.

[0006] As a preferred technical solution of this application, the first arc-shaped array, the second arc-shaped array, the third arc-shaped array, the fourth arc-shaped array, the grounding layer, and the antenna substrate are made into a horizontally polarized arc-shaped omnidirectional antenna. The horizontally polarized arc-shaped omnidirectional antenna uses arc-shaped and arc-shaped vibrators that combine fan-shaped and arc-shaped elements, and four sets of such arc-shaped vibrators are evenly placed on the circumference.

[0007] As a preferred technical solution of this application, the horizontally polarized fan-arc omnidirectional antenna has two designs: the first is a standing wave broadband design with a single fan-arc array, and the second is an overall design with four fan-arc arrays.

[0008] As a preferred technical solution of this application, in the first standing wave broadband design of a single fan arc array, for each fan arc array, in the matching design with a 50Ω impedance, the following variable parameters are designed: a1 is the outer arc length, a2 is the inner arc length, a3 is the distance between the inner and outer arc lengths, and b is the distance between the two arms.

[0009] As a preferred technical solution of this application, the horizontally polarized fan-shaped omnidirectional antenna continuously optimizes the dimensional parameters of each individual fan-shaped element through HFSS software to obtain an outer arc length a1=0.31λ, an inner arc length a2=0.185λ, an inner and outer arc distance a3=0.095λ, and a gap distance between the two arms b=0.021λ, where λ is the wavelength of the antenna's center frequency in the medium. Under these conditions, the antenna has good standing wave characteristics, with a standing wave ratio below 1.5 and a bandwidth of up to 51.1%.

[0010] As a preferred technical solution of this application, in the overall design of the second type of four arc-shaped fan arrays, the horizontally polarized arc-shaped omnidirectional antenna has four arc-shaped fan elements evenly placed on the circumference, and the four arc-shaped fan arrays are evenly placed around the circumference with point O as the center. Let the distance from each arc-shaped fan array to the center O be x, and the gap distance between adjacent arc-shaped fan arrays be y.

[0011] As a preferred technical solution of this application, the horizontally polarized fan-arc omnidirectional antenna continuously optimizes the dimensional parameters of the four fan-arc elements using HFSS software. Under the condition of equal amplitude and phase, when the distance from the center of the element to the center of the circle is x=(0.283~0.295)λ and the gap distance between elements is y=(0.068~0.075)λ, the antenna pattern has good characteristics within a 50% bandwidth range. The out-of-roundness of the antenna in the horizontal plane is less than ±0.5 dB, and the axial cross-polarization is less than -25 dB.

[0012] As a preferred technical solution of this application, the VSWR broadband design of the single fan-shaped array and the overall design of the four fan-shaped arrays are both optimized using HFSS software.

[0013] Compared with existing technologies, this invention provides a broadband horizontally polarized fan-arc omnidirectional antenna with the following advantages: This broadband horizontally polarized fan-arc omnidirectional antenna uses a combination of fan and arc shapes to form an array. Four arc-shaped fan elements are evenly placed on the circumference. By continuously optimizing the width of the fan-arc array arm and the distance between the arc-shaped fan elements in HFSS software, the distance from the center of the fan-arc array to the center of the circle achieves good performance indicators, solving the difficulty of narrow VSWR bandwidth and radiation pattern bandwidth of conventional horizontally polarized antennas. The overall design uses photolithography to etch four fan-arc arrays and a common ground layer on one side of an FR4 board or PTFE board, and a feed coupling balun and a 1-to-4 splitter network are etched on the other side. The entire broadband horizontally polarized fan-arc omnidirectional antenna has a simple structure, is easy to operate, and performs better than traditional methods. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of a broadband horizontally polarized fan-shaped omnidirectional antenna according to the present invention.

[0015] Figure 2 This is a schematic diagram of the structure of a single fan-arc array in a broadband horizontally polarized fan-arc omnidirectional antenna of the present invention.

[0016] Figure 3 This is a schematic diagram of the structure of four fan-arc array elements combined in a broadband horizontally polarized fan-arc omnidirectional antenna of the present invention.

[0017] Figure 4 This is a schematic diagram of the design results of the standing wave in a broadband horizontally polarized fan-shaped omnidirectional antenna according to the present invention.

[0018] Figure 5 This is a schematic diagram of the lowest frequency azimuth plane non-circularity and cross polarization in a broadband horizontally polarized fan-shaped omnidirectional antenna of the present invention.

[0019] Figure 6 This is a schematic diagram of the non-circularity and cross-polarization of the highest frequency azimuth plane in a broadband horizontally polarized fan-shaped omnidirectional antenna of the present invention.

[0020] In the diagram: 1. First arc-shaped array; 2. Second arc-shaped array; 3. Third arc-shaped array; 4. Fourth arc-shaped array; 5. Grounding layer; 6. Antenna substrate. Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] like Figure 1-6As shown, a broadband horizontally polarized fan-shaped omnidirectional antenna includes an antenna substrate 6. A first fan-shaped array 1, a second fan-shaped array 2, a third fan-shaped array 3, a fourth fan-shaped array 4, and a ground layer 5 are etched onto the antenna substrate 6. The first fan-shaped array 1, the second fan-shaped array 2, the third fan-shaped array 3, the fourth fan-shaped array 4, and the ground layer 5 are etched onto one side of the antenna substrate 6 using photoplotting technology. The antenna substrate 6 is either an FR plate or a polytetrafluoroethylene (PTFE) plate. A conventional feed coupling balun and a 1-to-4 splitter network are etched onto the other side of the antenna substrate 6.

[0025] Furthermore, the first arc-shaped element 1, the second arc-shaped element 2, the third arc-shaped element 3, the fourth arc-shaped element 4, the grounding layer 5, and the antenna substrate 6 are made into a horizontally polarized arc-shaped omnidirectional antenna. The horizontally polarized arc-shaped omnidirectional antenna uses arc-shaped elements that combine fan and arc shapes, and four sets of such arc-shaped elements are evenly placed on the circumference.

[0026] Furthermore, there are two designs for the horizontally polarized fan-arc omnidirectional antenna: the first is a standing wave broadband design with a single fan-arc array, and the second is an overall design with four fan-arc arrays.

[0027] Furthermore, in the first type of standing wave broadband design for a single arc array, for each arc array, in the matching design with a 50Ω impedance, the following variable parameters are designed: a1 is the outer arc length, a2 is the inner arc length, a3 is the distance between the inner and outer arc lengths, and b is the distance between the two arms.

[0028] Furthermore, the horizontally polarized fan-shaped omnidirectional antenna continuously optimizes the dimensional parameters of each individual fan-shaped element using HFSS software, resulting in an outer arc length a1=0.31λ, an inner arc length a2=0.185λ, an inner and outer arc distance a3=0.095λ, and a gap distance between the two arms b=0.021λ, where λ is the wavelength of the antenna's center frequency in the medium. Under these conditions, the antenna exhibits excellent standing wave characteristics, with a standing wave ratio below 1.5 and a bandwidth reaching 51.1%.

[0029] Furthermore, in the overall design of the second type of four arc-shaped array, the four arc-shaped elements of the horizontally polarized arc-shaped omnidirectional antenna are evenly placed on the circumference, and the four arc-shaped arrays are evenly placed around the circumference with point O as the center. Let the distance from each arc-shaped array to the center O be x, and the gap distance between adjacent arc-shaped arrays be y.

[0030] Furthermore, the horizontally polarized fan-arc omnidirectional antenna continuously optimizes the dimensional parameters of the four fan-arc elements using HFSS software. Under the condition of equal amplitude and in-phase, when the distance from the center of the element to the center of the circle is x=(0.283~0.295)λ and the gap distance between elements is y=(0.068~0.075)λ, the antenna pattern has good characteristics within 50% bandwidth. The out-of-roundness of the antenna in the horizontal plane is less than ±0.5 dB, and the axial cross-polarization is less than -25 dB.

[0031] Furthermore, HFSS software was used for parameter optimization in both the broadband design of a single fan-shaped array and the overall design of four fan-shaped arrays.

[0032] On the antenna substrate 6, which is an FR board or a polytetrafluoroethylene board, a first arc array 1, a second arc array 2, a third arc array 3, a fourth arc array 4 and a common ground layer 5 are etched on one side using photoplotting technology. On the other side, a conventional feed coupling balun and a one-to-four composite network are etched.

[0033] This invention patent comprises two parts: a standing wave broadband design for a single fan-shaped array and a radiation pattern broadband design for four fan-shaped arrays. The design is illustrated here using a frequency band of 1.5 GHz to 3 GHz as an example, but is applicable to all other frequency bands and is not a limitation thereof. Example

[0034] Broadband VSWR design of a single sector arc array like Figure 2 As shown, for each sector arc array, in the matching design with a 50Ω impedance, the following variable parameters are designed. a1 is the outer arc length, a2 is the inner arc length, a3 is the distance between the inner and outer arc lengths, and b is the distance between the two arms. In this invention, the left and right arms are completely identical.

[0035] The impedance of the fan-shaped arc array clearly depends on the variables a1, a2, a3, and b, which are set... Z = Z(a1, a2, a3, b) Given a 50Ω characteristic impedance at Z0, then the standing wave... Γ=( Z O -Z) / ( Z O +Z) VSWR=(1+Γ) / (1-Γ) The objective function is set to VSWR ≤ 1.5. By continuously optimizing these four variables (a1, a2, a3, b) within a frequency range of 1.5 GHz to 3 GHz, the result shows that VSWR ≤ 1.5 within a frequency range of 1.62 GHz to 2.85 GHz. Within a relative bandwidth of 51.1%, the VSWR is less than 1.5, far exceeding the bandwidth of conventional horizontally polarized antennas. Example

[0036] Overall design of four fan-shaped arrays like Figure 3 As shown, four fan-shaped arc arrays are evenly placed around a circle centered at point o. Let the distance from each fan-shaped arc array to the center o be x, and the gap distance between adjacent fan-shaped arc arrays be y.

[0037] The radiation field of each fan-shaped array A = μI(△l)e (-jkr) / 4лr In the above formula, I is the amplitude of the given fan-shaped arc array, and r is the phase-dependent distance. △l is a variable related to the size of the arc-shaped strobe. The total field radiated by the four sector arc arrays is also related to the variables x and y. A0=A1(x,y)+A2(x,y)+A3(x,y)+A4(x,y) The objective function A0 is set to |△A0|≤0.5dB within the 360° azimuth plane. Variables I, Φ, x, and y are continuously optimized within the frequency range of 1.5GHz to 3GHz. The optimal result is that, under the conditions of equal amplitude (equal I) and in-phase (equal Φ) for four fan-shaped arrays, when x=(0.283∽0.295)λ and y=(0.068∽0.075)λ, the radiation pattern is optimized within the range of 1.7GHz to 2.83GHz. This is reflected in: antenna out-of-roundness in the horizontal plane being less than ±0.5 dB, and axial cross-polarization being less than -25 dB.

[0038] The advantages of this invention patent can be illustrated by the comparison in the table below. Design results of standing waves like Figure 4 As shown; Design results of the horizontal plane of the radiation pattern Lowest frequency 1.7 GHz Azimuth surface non-circularity and cross polarization like Figure 5 As shown; Highest frequency 2.83 GHz Azimuth surface non-circularity and cross polarization like Figure 6As shown; It should be noted that, in this document, relational terms such as first and second (number one, number two), etc., are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A broadband horizontally polarized fan-shaped omnidirectional antenna, comprising an antenna substrate (6), characterized in that: The antenna substrate (6) is etched with a first arc-shaped array (1), a second arc-shaped array (2), a third arc-shaped array (3), a fourth arc-shaped array (4) and a ground layer (5). The first arc-shaped array (1), the second arc-shaped array (2), the third arc-shaped array (3), the fourth arc-shaped array (4) and the ground layer (5) are etched on one side of the antenna substrate (6) by photolithography. The antenna substrate (6) is either an FR4 board or a polytetrafluoroethylene board. The other side of the antenna substrate (6) is etched with a conventional feed coupling balun and a one-to-four composite network. The first fan-shaped arc array (1), the second fan-shaped arc array (2), the third fan-shaped arc array (3), the fourth fan-shaped arc array (4), the grounding layer (5), and the antenna substrate (6) are used to make a horizontally polarized fan-shaped arc omnidirectional antenna. The horizontally polarized fan-shaped arc omnidirectional antenna uses a fan-shaped arc oscillator that combines fan shape and arc shape, and four sets of such fan-shaped arc oscillators are evenly placed on the circumference. The horizontally polarized fan-arc omnidirectional antenna has two designs: the first is a standing wave broadband design with a single fan-arc array, and the second is an overall design with four fan-arc arrays. In the first type of standing wave broadband design for a single arc array, for each arc array, in the matching design with a 50Ω impedance, the following variable parameters are designed: a1 is the outer arc length, a2 is the inner arc length, a3 is the distance between the inner and outer arc lengths, and b is the distance between the two arms. The horizontally polarized fan-shaped omnidirectional antenna is continuously optimized using HFSS software to obtain the following dimensional parameters for each fan-shaped element: outer arc length a1 = 0.31λ, inner arc length a2 = 0.185λ, inner and outer arc distance a3 = 0.095λ, and gap distance between the two arms b = 0.021λ, where λ is the wavelength of the antenna's center frequency in the medium. Under these conditions, the antenna exhibits excellent standing wave characteristics, with a standing wave ratio below 1.5 and a bandwidth reaching 51.1%. In the overall design of the second type of four fan arc array, the horizontally polarized fan arc omnidirectional antenna has four fan arc elements evenly placed on the circumference, and the four fan arc arrays are evenly placed around the circumference with point O as the center. Let the distance from the center of each fan arc array to the center O be x, and the gap distance between adjacent fan arc arrays be y. The horizontally polarized fan-shaped omnidirectional antenna continuously optimizes the dimensional parameters of the four fan-shaped elements using HFSS software. Under the condition of equal amplitude and in-phase, when the distance from the center of each fan-shaped element to the center o is x = (0.283~0.295)λ, and the gap distance between elements is y = (0.068~0.075)λ, the antenna pattern has good characteristics within a 50% bandwidth range. The out-of-roundness of the antenna in the horizontal plane is less than ±0.5dB, and the axial cross-polarization is less than -25dB. The VSWR broadband design of the single sector array and the overall design of the four sector arrays were both optimized using HFSS software.

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