A broadband low VSWR antenna and antenna array device

Abstract

This invention relates to a broadband low VSWR antenna and an antenna array device. The antenna includes a substrate, a radiator, and a feeding structure. The radiator is fixedly disposed on one side of the substrate. The radiator has a tapered opening in the radiation direction. The radiator is symmetrical about the axis of the tapered opening, and the size of the tapered opening gradually increases in the extension direction. A resonant cavity is provided at the bottom of the tapered opening, and the resonant cavity is located near the bottom of the substrate. U-shaped slots extending from the sides of the radiator towards the tapered opening are provided on both sides of the radiator, and the U-shaped slots are symmetrically arranged about the axis of the tapered opening. The feeding structure is fixedly disposed on the other side of the substrate and located near the resonant cavity at the bottom of the substrate. By providing U-shaped slots on both sides of the radiator, the low-frequency impedance bandwidth of the antenna is improved without changing the antenna size, thereby enhancing the antenna performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of antennas, in particular to a wideband low standing wave antenna and an antenna array device. BACKGROUND

[0002] The antenna is a key component for radiation and reception of energy in modern wireless communication systems. Since wireless communication devices all need antennas for signal transmission and reception, the signal transmission and reception capability of the antenna directly determines the performance of the wireless communication system at many times.

[0003] The Vivaldi antenna is a planar ultra-wideband antenna composed of a slot line with exponentially varying slot width. Due to its advantages of ultra-wideband, low profile, easy processing, etc., it is widely used in communication, radar measurement and other fields. The Vivaldi antenna utilizes the radiation characteristics of the slot line when the slot width is much larger than half the working wavelength, gradually increases the slot width to radiate outward or receive electromagnetic waves inward. At different frequencies, different parts of the antenna emit or receive electromagnetic waves, and each radiation part is unchanged relative to the wavelength of the corresponding different frequency signal, so theoretically it has a very wide bandwidth and the same beam width in this frequency range. The surface current of the Vivaldi antenna is mainly concentrated on the inner edge of the slot line, so the performance of this type of antenna is mainly determined by the shape of the slot line and the feeding method.

[0004] The existing Vivaldi antenna mainly has the following technical problems:

[0005] 1) The transverse size of the antenna determines the low frequency band of the impedance bandwidth, that is, the transverse size of the antenna should be more than half the wavelength of the lowest frequency. Due to the limitation of the size of the antenna, when the transverse size of the antenna is too small, the impedance matching of the low frequency band is affected, and sufficient working bandwidth cannot be achieved;

[0006] 2) The coupling degree between the cross-set feeding microstrip line located on the lower surface of the substrate and the slot line located on the upper surface of the substrate is poor, which is not conducive to the matching of the antenna.

[0007] Therefore, it is necessary to provide a wideband low standing wave antenna that improves the low frequency impedance bandwidth of the antenna and meets the requirements of the antenna standing wave ratio to solve the above technical problems. SUMMARY

[0008] In order to solve the above technical problems, the present application provides a wideband low standing wave antenna. The problem that the low frequency band is limited by the size of the antenna, the transverse size of the antenna is too small, the impedance matching of the low frequency band is affected, and sufficient working bandwidth cannot be achieved, which affects the signal transmission and reception performance of the antenna in the prior art is solved.

[0009] The technical effects of the present application are achieved as follows:

[0010] A broadband low standing wave antenna, comprising:

[0011] a substrate,

[0012] a radiator fixed on one side of the substrate, the radiator is provided with a tapered opening in the radiation direction, the radiator is symmetrically structured with the axial direction of the tapered opening as the axis of symmetry, the size of the tapered opening gradually increases in the direction of the opening extension, the bottom of the tapered opening is provided with a resonant cavity, the resonant cavity is arranged close to the bottom of the substrate, both sides of the radiator are provided with a U-shaped slot extending from the side edge to the tapered opening, the U-shaped slots on both sides of the radiator are symmetrically arranged with the axial direction of the tapered opening as the axis of symmetry;

[0013] a feeding structure fixed on the other side of the substrate, the feeding structure is arranged at the bottom of the substrate close to the resonant cavity. By providing U-shaped slots on both sides of the radiator, the low-frequency impedance bandwidth of the antenna is improved without changing the size of the antenna, the antenna has a larger bandwidth, the gain flatness of the antenna is improved, the performance of the antenna signal transmission and reception is improved, and the miniaturization of the antenna is promoted. The problem of insufficient working bandwidth and the influence of antenna signal transmission performance due to the limitation of antenna size in the low frequency band is solved.

[0014] Further, the U-shaped slot includes a first slot and a second slot, the first slot and the second slot are parallel, the length of the second slot is less than the length of the first slot, one end of the first slot is located at the side edge of the radiator, and the other end of the first slot is in communication with the second slot.

[0015] Further, the length of the U-shaped slot is 1 / 4 of the wavelength of the electromagnetic wave emitted by the broadband low standing wave antenna.

[0016] Further, the feeding structure includes a right-angled feeding structure and a sector-shaped feeding structure, the right-angled feeding structure includes a first right-angled side and a second right-angled side connected to each other, the axial direction of the first right-angled side and the axial direction of the second right-angled side are perpendicular to each other, the first right-angled side is connected to the apex of the sector-shaped feeding structure, and the second right-angled side is arranged at the bottom of the broadband low standing wave antenna for connection with a feeding port. By additionally providing a sector-shaped feeding structure at the end of the right-angled feeding structure, the coupling degree with the tapered opening located on the other side of the substrate is improved, the standing wave ratio of the antenna is reduced, which is conducive to the matching of the antenna and thus the radiation of electromagnetic waves.

[0017] Further, the axial direction of the first right-angled side is the axis of symmetry of the sector-shaped feeding structure, and the axial direction of the first right-angled side is perpendicular to the axial direction of the tapered opening.

[0018] Further, the vertex of the fan-shaped feed structure and the position of the tapered opening close to the resonant cavity overlap in the Y direction, and the fan-shaped feed structure and the second right-angle side are respectively located on the two sides of the axis of the tapered opening.

[0019] Further, the vertex angle of the fan-shaped feed structure is 70-85 degrees.

[0020] Further, the radius of the fan-shaped feed structure is 4-5 mm.

[0021] Further, the resonant cavity is a circular structure, and the diameter of the circular structure is 1 / 4 of the wavelength of the electromagnetic wave emitted by the wideband low standing wave antenna.

[0022] In addition, an antenna array device is also included, which comprises the wideband low standing wave antenna, and the antenna array device is a two-dimensional antenna array by arranging multiple wideband low standing wave antennas to form a plane wave in a short distance.

[0023] As described above, the present application has the following beneficial effects:

[0024] 1) By arranging the U-shaped slot on both sides of the radiator, the low-frequency impedance bandwidth of the antenna is increased without changing the size of the antenna, so that the antenna has the characteristics of large bandwidth, the gain flatness of the antenna is improved, the performance of the antenna signal transmission and reception is improved, and the miniaturization of the antenna is promoted; solve the problem that in the prior art, due to the limitation of the low frequency band by the size of the antenna, when the horizontal size of the antenna is too small, the impedance matching of the low frequency band is affected, and sufficient working bandwidth cannot be achieved, which affects the performance of the antenna signal transmission and reception.

[0025] 2) By additionally arranging the fan-shaped feed structure at the end of the right-angle feed structure, the coupling degree with the tapered opening on the other side of the substrate is improved, the standing wave ratio of the antenna is reduced, which is beneficial to the matching of the antenna, and thus beneficial to the radiation of electromagnetic waves. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0027] Figure 1 A structure schematic view of a wideband low standing wave antenna provided by an embodiment of the present application on one side of a radiator;

[0028] Figure 2 A structure schematic view of a wideband low standing wave antenna provided by an embodiment of the present application on one side of a feed structure;

[0029] Figure 3 A wideband low standing wave antenna provided by an embodiment of the present application has a simulation VSWR graph as shown in the figure.

[0030] In the figure, the reference signs correspond to:

[0031] The substrate 1, the radiator 2, the gradually-changing opening 3, the waveguide area 31, the radiation area 32, the resonant cavity 4, the U-shaped slot 5, the first slot 51, the second slot 52, the feeding structure 6, the right-angle feeding structure 61, the first right-angle side 611, the second right-angle side 612, the fan-shaped feeding structure 62. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be apparently and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0033] It should be noted that the terms "first", "second" and the like in the description and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units need not be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0034] Embodiment 1:

[0035] As shown in Figure 1 and Figure 2 A wideband low standing wave antenna includes a substrate 1, a radiator 2 and a feeding structure 6. The radiator 2 is fixed on one side of the substrate 1. The radiator 2 is provided with a gradually-changing opening 3 in the radiation direction. The radiator 2 has a symmetrical structure with the axial direction of the gradually-changing opening 3 as the symmetry axis. The size of the gradually-changing opening 3 gradually increases in the extension direction of the opening. The bottom of the gradually-changing opening 3 is provided with a resonant cavity 4, which is arranged close to the bottom of the substrate 1. The two sides of the radiator 2 are each provided with a U-shaped slot 5 extending from the side edge to the gradually-changing opening 3. The U-shaped slots 5 on the two sides of the radiator 2 are symmetrically arranged with the axial direction of the gradually-changing opening 3 as the symmetry axis. The feeding structure 6 is fixed on the other side of the substrate 1. The feeding structure 6 is arranged on the bottom of the substrate 1 close to the resonant cavity 4.

[0036] It should be noted that the tapered opening 3 can be divided into two parts according to different functions, one part is the waveguide area 31 with equal width, that is, the slot line, and the other part is the radiation area 32 with tapered width. The waveguide area 31 is the narrow opening end, and the corresponding working frequency band of the narrow opening end is high frequency. The radiation area 32 is the wide opening end, and the corresponding working frequency band of the wide opening end is low frequency. For the slot line working in the matching state, if the slot width is much smaller than half the working wavelength, the energy in the slot line will be confined between the tapered openings 3 of the radiator 2 and will not be radiated out. Therefore, by using the radiation characteristics of the slot line with a width much greater than half the working wavelength, the slot line width is gradually increased to form the radiation area 32 to radiate outward or receive electromagnetic waves inward.

[0037] In the formula, since the transverse dimension of the antenna should be greater than half the wavelength of the lowest frequency, the transverse dimension of the antenna determines the low frequency band of the impedance bandwidth. By providing the U-shaped slot 5 on both sides of the radiator 2, the low frequency impedance bandwidth of the antenna is increased without changing the size of the antenna, so that the antenna has a large bandwidth, improves the gain flatness of the antenna, and improves the performance of the antenna signal transmission and reception.

[0038] Specifically, the left and right sides of the radiator 2 are provided with U-shaped slots 5 extending from the side edges to the tapered openings 3 with respect to the center axis of the antenna, which ensures the consistency of the current distribution in the antenna and the symmetry of the radiation pattern, and improves the radiation performance of the antenna.

[0039] Specifically, the substrate 1 is a dielectric plate made of materials such as phenolic resin, epoxy resin or polytetrafluoroethylene, and is preferably made of FR4 material. The radiator 2 can use a metal plating layer on one side of the dielectric plate, or can be a metal plate directly. The metal material is preferably copper.

[0040] Preferably, the U-shaped slot 5 includes a first slot 51 and a second slot 52, the first slot 51 and the second slot 52 are parallel, the length of the second slot 52 is less than the length of the first slot 51, one end of the first slot 51 is located at the side edge of the radiator 2, and the other end of the first slot 51 is in communication with the second slot 52.

[0041] Preferably, the length of the U-shaped slot 5 is 1 / 4 of the wavelength of the electromagnetic wave emitted by the wideband low standing wave antenna.

[0042] Specifically, as shown in Figure 1 the transverse dimension of the antenna is 62 mm, the longitudinal dimension of the antenna is 64 mm, and the length of the U-shaped slot 5 is 30-35 mm. The transverse dimension of the antenna is the length of the antenna, the length direction is the X direction, the longitudinal dimension of the antenna is the height of the antenna, the height direction is the Z direction, and the Y direction is perpendicular to the X direction and the Z direction, that is, perpendicular to the plane of the substrate 1.

[0043] Preferably, the feeding structure 6 comprises a right-angle feeding structure 61 and a sector feeding structure 62, the right-angle feeding structure 61 comprises a first right-angle side 611 and a second right-angle side 612 connected to each other, the axial direction of the first right-angle side 611 and the axial direction of the second right-angle side 612 are perpendicular to each other, the first right-angle side 611 is connected to the vertex of the sector feeding structure 62, and the second right-angle side 612 is arranged at the bottom of the broadband low standing wave antenna for being connected to the feeding port. By additionally arranging the sector feeding structure 62 at the end of the right-angle feeding structure 61, the coupling degree with the tapered opening 3 located on the other side of the substrate 1 is improved, the standing wave ratio of the antenna is reduced, the matching of the antenna is facilitated, and thus the radiation of electromagnetic waves is facilitated.

[0044] Specifically, the feeding structure 6 can use a metal plating layer on one side of the dielectric plate, or can be a metal plate directly, and the metal material is preferably copper.

[0045] Specifically, the first right-angle side 611 is located in the horizontal direction, and the second right-angle side 612 is located in the vertical direction.

[0046] Preferably, the axial direction of the first right-angle side 611 is the symmetry axis of the sector feeding structure 62, and the axial direction of the first right-angle side 611 is perpendicular to the axial direction of the tapered opening 3.

[0047] Preferably, the vertex of the sector feeding structure 62 and the position of the tapered opening 3 close to the resonant cavity 4 overlap in the Y direction, and the sector feeding structure 62 and the second right-angle side 612 are respectively located on the two sides of the axial direction of the tapered opening 3.

[0048] Preferably, the vertex angle of the sector feeding structure 62 is 70-85 degrees, and is preferably 80 degrees.

[0049] Preferably, the radius of the sector feeding structure 62 is 4-5 mm, and is preferably 4.5 mm.

[0050] Preferably, the resonant cavity 4 is a circular structure, and the diameter of the circular structure is 1 / 4 of the wavelength of the electromagnetic wave emitted by the broadband low standing wave antenna.

[0051] Specifically, the distance from the edge of the sector feeding structure 62 adjacent to the resonant cavity 4 to the nearest position of the cavity wall of the resonant cavity 4 is 1-3 mm.

[0052] In this embodiment, a broadband low standing wave antenna designed based on the idea of the application is established, and a model corresponding to the broadband low standing wave antenna of the application is simulated, as shown in FIG. 2, and the standing wave ratio (VSWR) simulation result of the broadband low standing wave antenna of the application is obtained. Figure 2

[0053] Figure 2 ​The standing wave ratio simulation result in the application shows that the wideband low standing wave antenna in the application has a VSWR <1.5 in a frequency range of 1.7GHz-6GHz, which increases the low-frequency impedance bandwidth of the antenna without changing the size of the antenna, makes the antenna have a large bandwidth, improves the performance of the antenna signal transmission and reception, and solves the problem in the prior art that the low-frequency band is limited by the size of the antenna, when the horizontal size of the antenna is too small, the impedance matching of the low-frequency band is affected, and sufficient working bandwidth cannot be achieved, which affects the performance of the antenna signal transmission and reception.

[0054] Embodiment 2:

[0055] An antenna array device includes the wideband low standing wave antenna in embodiment 1, and the antenna array device is formed as a two-dimensional antenna array by arranging multiple wideband low standing wave antennas to form a plane wave in a short distance. The multiple wideband low standing wave antennas have better radiation performance, and provide higher flexibility for capturing or tracking signals during movement.

[0056] As described above, the application has the following beneficial effects:

[0057] 1) By arranging U-shaped slots on both sides of the radiator, the low-frequency impedance bandwidth of the antenna is increased without changing the size of the antenna, the antenna has a large bandwidth, the gain flatness of the antenna is improved, the performance of the antenna signal transmission and reception is improved, and the miniaturization of the antenna is promoted; the problem in the prior art that the low-frequency band is limited by the size of the antenna, when the horizontal size of the antenna is too small, the impedance matching of the low-frequency band is affected, sufficient working bandwidth cannot be achieved, and the performance of the antenna signal transmission and reception is affected.

[0058] 2) By additionally arranging a fan-shaped feeding structure at the end of the right-angle feeding structure, the coupling degree with the gradually changing opening located on the other side of the substrate is improved, the standing wave ratio of the antenna is reduced, the matching of the antenna is facilitated, and the radiation of electromagnetic waves is facilitated.

[0059] Although the application has been described by preferred embodiments, the application is not limited to the embodiments described herein, and various changes and variations are included without departing from the scope of the application.

[0060] In this document, the front, back, up, down and other orientation words are defined according to the position of the parts in the drawing and the position of the parts relative to each other, only for the purpose of expressing the clarity and convenience of the technical scheme. It should be understood that the use of the orientation words should not limit the scope of the application claimed.

[0061] In the case of no conflict, the features in the above embodiments and the embodiments can be combined with each other.

[0062] The above merely provides the preferred embodiment of the present application, and cannot allude the protection scope of the present application, therefore, any equivalent changes made according to the claims of the present application shall be within the scope of the present application.

Claims

1. A broadband low standing wave antenna, characterized by, It comprises: a substrate (1), a radiator (2) fixed on one side of the substrate (1), the radiator (2) is provided with a gradually changing opening (3) in the radiation direction, the radiator (2) is symmetrically structured with the axis of the gradually changing opening (3) as the axis of symmetry, the gradually changing opening (3) gradually increases in size in the direction of opening extension, the bottom of the gradually changing opening (3) is provided with a resonant cavity (4), the resonant cavity (4) is arranged close to the bottom of the substrate (1), both sides of the radiator (2) are provided with a U-shaped slot (5) extending from the side to the gradually changing opening (3), the U-shaped slots (5) on both sides of the radiator (2) are symmetrically arranged with the axis of the gradually changing opening (3) as the axis of symmetry; the U-shaped slot (5) comprises a first slot (51) and a second slot (52), the first slot (51) and the second slot (52) are parallel, the length of the second slot (52) is less than the length of the first slot (51), one end of the first slot (51) is located at the side of the radiator (2), the other end of the first slot (51) is communicated with the second slot (52); the length of the U-shaped slot (5) is 1 / 4 of the wavelength of the electromagnetic wave emitted by the wideband low-standing wave antenna; a feeding structure (6) fixed on the other side of the substrate (1), the feeding structure (6) is arranged on the bottom of the substrate (1) close to the resonant cavity (4).

2. The broadband low standing wave antenna according to claim 1, wherein The feeding structure (6) comprises a right-angle feeding structure (61) and a sectorial feeding structure (62), the right-angle feeding structure (61) comprises a first right-angle side (611) and a second right-angle side (612) connected to each other, the axis of the first right-angle side (611) and the axis of the second right-angle side (612) are perpendicular to each other, the first right-angle side (611) is connected with the vertex of the sectorial feeding structure (62), and the second right-angle side (612) is arranged at the bottom of the wideband low-standing wave antenna for connection with a feeding port.

3. The broadband low standing wave antenna of claim 2, wherein, The axis of the first right-angle side (611) is the axis of symmetry of the sectorial feeding structure (62), and the axis of the first right-angle side (611) is perpendicular to the axis of the gradually changing opening (3).

4. The broadband low standing wave antenna of claim 3, wherein, The vertex of the sectorial feeding structure (62) and the position of the gradually changing opening (3) close to the resonant cavity (4) overlap in the Y direction, and the sectorial feeding structure (62) and the second right-angle side (612) are respectively located on both sides of the axis of the gradually changing opening (3).

5. The broadband low standing wave antenna of claim 2, wherein, The vertex angle of the sectorial feeding structure (62) is 70-85 degrees.

6. The broadband low standing wave antenna of claim 2, wherein, The radius of the sectorial feeding structure (62) is 4-5 mm.

7. The broadband low standing wave antenna of claim 1, wherein, The resonant cavity (4) is a circular structure, and the diameter of the circular structure is 1 / 4 of the wavelength of the electromagnetic wave emitted by the wideband low-standing wave antenna.

8. An antenna array apparatus, comprising: The antenna array device comprises a plurality of wideband low-standing wave antennas as claimed in any one of claims 1-7, and the antenna array device is a two-dimensional antenna array by arranging a plurality of wideband low-standing wave antennas to form a plane wave in a short distance.

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