Broadband low-profile magnetoelectric dipole antenna for ultrashort wave directional communication

Abstract

The invention discloses a broadband low-profile magnetoelectric dipole antenna for ultrashort wave directional communication, which comprises an antenna metal floor, a stepped metal feeder line and two rectangular metal sheets, and is characterized in that the stepped metal feeder line is arranged between the two rectangular metal sheets; the inner side of each rectangular metal sheet is fixedly connected with the antenna metal floor through a folding short-circuit metal wall; and two suspended U-shaped parasitic metal sheets are arranged at the corners of the outer side of each rectangular metal sheet. The short-circuit metal wall of the magnetoelectric dipole antenna is folded, so that the profile height of the antenna is effectively reduced, and meanwhile, the short-circuit metal wall of the antenna is slotted, so that the impedance matching characteristic in an antenna band is improved. The four U-shaped parasitic metal sheets are introduced around the antenna, so that the working bandwidth of the antenna is expanded under the condition that the antenna has relatively high gain, and the ultra-short wave directional antenna has the advantages of simple structure, wide frequency band, low profile, high directionality and the like, and can be applied to ultra-short wave directional communication.

Description

Technical Field

[0001] The invention relates to the field of antenna technology, and in particular to a broadband low-profile magnetoelectric dipole antenna for ultra-short wave directional communication. Background Art

[0002] Ultrashort wave communication is widely used in mobile communication, military communication and emergency communication, and has the advantages of long communication distance and strong anti-interference ability. In order to achieve signal transmission and reception in a wide frequency range, the ultrashort wave antenna needs to have wideband characteristics. At the same time, in order to improve the communication distance of the ultrashort wave antenna, it is necessary to design a directional antenna to increase the antenna gain in the specified direction. The magnetoelectric dipole antenna has the characteristics of broadband, high gain, simple structure and easy processing. Applying it to ultrashort wave directional communication can realize the broadband and miniaturized design of ultrashort wave directional antenna.

[0003] Commonly used broadband directional antennas include log-periodic antennas and magnetoelectric dipole antennas. Log-periodic antennas are a typical non-frequency-variable antenna. By loading or bending the oscillator, the size of the log-periodic antenna can be effectively reduced to achieve miniaturization. The height of a typical magnetoelectric dipole antenna is about 1 / 4 wavelength (with the center frequency as a reference). By folding the magnetic dipole, using inclined metal walls and metamaterial loading, the profile height of the magnetoelectric dipole antenna can be effectively reduced to achieve a low-profile design. For log-periodic antennas working in the ultra-short wave band, due to the long wavelength, in order to meet good radiation characteristics, their installation height is relatively high, and it is difficult to achieve low-profile characteristics, which is not conducive to the maintenance and transportation of the antenna. At present, the miniaturization of magnetoelectric dipole antennas is mainly concentrated in the microwave band, and there is little research on magnetoelectric dipoles working in the ultra-short wave band. If the existing magnetoelectric dipole antenna is directly used in the ultra-short wave band, it is difficult to meet both the profile height and bandwidth, and it cannot be directly applied to ultra-short wave directional communication. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention proposes a broadband, low-profile magnetoelectric dipole antenna for ultra-short wave directional communication, thereby solving the problem that the profile height and bandwidth of the traditional magnetoelectric dipole antenna are difficult to simultaneously meet the ultra-short wave communication requirements.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0006] Provided is a wide-band low-profile magnetoelectric dipole antenna for ultra-short wave directional communication, comprising an antenna metal floor, a stepped metal feeder and two rectangular metal sheets parallel to the antenna metal floor, wherein the two rectangular metal sheets are symmetrically arranged above the antenna metal floor, the inner side of each rectangular metal sheet is connected to a folded short-circuit metal wall, and the bottom of each folded short-circuit metal wall is fixedly connected to the antenna metal floor; the stepped metal feeder is arranged between the two rectangular metal sheets, one end of the stepped metal feeder is open-circuited, and the other end is connected to the antenna metal floor; two U-shaped parasitic metal sheets are arranged at the outer corners of each rectangular metal sheet, and each U-shaped parasitic metal sheet is suspended and fixed below the rectangular metal sheet through a plurality of insulating support columns.

[0007] Furthermore, the stepped metal feed line includes a first folded transmission line, a second folded transmission line and a coupling strip line located in the same plane as the rectangular metal sheet, one side of the coupling strip line is fixedly connected to the upper side of the first folded transmission line, a first L-shaped bending portion is arranged at the bottom of the first folded transmission line, the first L-shaped bending portion forms an open circuit with the antenna metal floor, the other side of the coupling strip line is fixedly connected to the upper side of the second folded transmission line, an outward bending protrusion is arranged at the bottom of the second folded transmission line, and the bending protrusion is fixedly connected to the antenna metal floor through a feeding port.

[0008] Furthermore, each folded short-circuit metal wall is provided with a strip groove matching the step metal feeder line, the height of the strip groove is equal to the height of the step metal feeder line, and the width of the strip groove is equal to the width of the step metal feeder line.

[0009] Furthermore, partial projections of the rectangular metal sheet and the U-shaped parasitic metal sheet on the horizontal plane overlap.

[0010] Furthermore, a second L-shaped bending portion facing outward is provided at the bottom of the folded short-circuit metal wall, and the folded short-circuit metal wall is fixedly connected to the antenna metal floor via the second L-shaped bending portion.

[0011] Furthermore, the metal floor is in a grid shape.

[0012] Furthermore, the insulating support column is made of polytetrafluoroethylene.

[0013] Furthermore, the rectangular metal sheet and the folded short-circuit metal wall are integrally bent and formed.

[0014] Furthermore, the U-shaped parasitic metal sheet is formed by integral bending.

[0015] The beneficial effects of the present invention are:

[0016] The present invention effectively reduces the profile height of the antenna by folding the short-circuit metal wall of the magnetoelectric dipole antenna, and improves the impedance matching characteristics within the antenna band by slotting the short-circuit metal wall of the antenna. By introducing four U-shaped parasitic metal sheets around the antenna, the working bandwidth of the antenna is expanded while ensuring that the antenna has a high gain. It has the advantages of simple structure, wide bandwidth, low profile, strong directivity, etc., and can be applied to ultra-short wave directional communication.

[0017] The present invention improves the magnetic dipole of the magnetoelectric dipole antenna into a folded short-circuit metal wall, effectively reducing the cross-sectional height of the antenna, which is only 0.163 wavelengths (center frequency 50MHz). The folded short-circuit metal wall is slotted to improve the impedance matching characteristics within the antenna band. By introducing four U-shaped parasitic metal sheets around the antenna, the current path of the antenna at low frequency is effectively extended, and the working bandwidth of the antenna is expanded, with a relative bandwidth greater than 80%. The designed magnetoelectric dipole antenna has the advantages of simple structure, wide bandwidth, low profile, strong directivity, etc., and can be applied to ultra-short wave directional communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a front view of a broadband low-profile magneto-electric dipole antenna;

[0019] Figure 2 It is a top view of a broadband low-profile magneto-electric dipole antenna;

[0020] Figure 3 This is a three-dimensional structural diagram of the magnetoelectric dipole antenna;

[0021] Figure 4 It is a three-dimensional structural diagram of the stepped metal feeder;

[0022] Figure 5 The standing wave ratio and gain curve of the antenna of the present invention;

[0023] Figure 6 is the directional diagram of the antenna of the present invention at 30 MHz;

[0024] Figure 7 is the directional diagram of the antenna of the present invention at 50 MHz;

[0025] Figure 8 is the directional diagram of the antenna of the present invention at 70 MHz;

[0026] The main components in the figure are described as follows:

[0027] 1. Rectangular metal sheet; 2. Folded short-circuit metal wall; 3. Stepped metal feed line; 4. U-shaped parasitic metal sheet; 5. Metal floor; 6. Insulating support column; 71. First folded transmission line; 72. Second folded transmission line; 8. Coupled strip line; 9. Feed port. DETAILED DESCRIPTION

[0028] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0029] like Figure 1 , 2 As shown in Figure 3, the antenna metal floor 5, the stepped metal feed line 3 and two rectangular metal sheets 1 parallel to the antenna metal floor 5, the two rectangular metal sheets 1 are symmetrically arranged above the antenna metal floor 5, the inner side of each rectangular metal sheet 1 is connected to a folded short-circuit metal wall 2, and the bottom of each folded short-circuit metal wall 2 is fixedly connected to the antenna metal floor 5. The rectangular metal sheet 1 and the folded short-circuit metal wall 2 are formed by integral bending, the two rectangular metal sheets 1 serve as the electric dipoles of the antenna, and the two folded short-circuit metal walls 2 constitute the magnetic dipoles of the antenna. A certain distance is left between the two rectangular metal sheets 1, the stepped metal feed line 3 is arranged between the two rectangular metal sheets 1, one end of the stepped metal feed line 3 is open, and the other end is connected to the antenna metal floor 5. Two U-shaped parasitic metal sheets 4 are arranged at the outer corners of each rectangular metal sheet 1, and the U-shaped parasitic metal sheet 4 is formed by integral bending, and the bending angle is preferably 90 degrees. Each U-shaped parasitic metal sheet 4 is suspended and fixed below the rectangular metal sheet 1 through a plurality of insulating support columns 6, and the rectangular metal sheet 1 and the U-shaped parasitic metal sheet 4 partially overlap in horizontal plane projection. In the present invention, the bending angle is 90 degrees. Among them, the rectangular metal sheet 1, the folded short-circuit metal wall 2, the stepped metal feed line 3, the U-shaped parasitic metal 4 and the antenna metal floor 5 are preferably made of aluminum.

[0030] like Figure 4 As shown, the stepped metal feed line 3 includes a first folded transmission line 71, a second folded transmission line 72 and a coupling strip line 8 located in the same plane as the rectangular metal sheet 1, one side of the coupling strip line 8 is fixedly connected to the upper side of the first folded transmission line 71, a first L-shaped bending portion is arranged at the bottom of the first folded transmission line 71, and the first L-shaped bending portion forms an open circuit with the antenna metal floor 5, the other side of the coupling strip line 8 is fixedly connected to the upper side of the second folded transmission line 72, an outward bending protrusion is arranged at the bottom of the second folded transmission line 72, and the bending protrusion is fixedly connected to the antenna metal floor 5 through the feeding port 9, the bottom of the first folded transmission line 71 is open, and the bottom of the second folded transmission line 72 is the feeding port 9, so as to realize coupling feeding of the antenna unit.

[0031] In this embodiment, a strip groove matching the stepped metal feed line 3 is provided on each folded short-circuit metal wall 2, the height of the strip groove is equal to the height of the stepped metal feed line 3, and the width of the strip groove is equal to the width of the stepped metal feed line 3. The center of each folded short-circuit metal wall 2 is grooved in the longitudinal direction to form a strip groove, and the strip groove and the stepped metal feed line 3 form an approximately complementary structure, which can improve the impedance matching of the antenna and increase the relative bandwidth of the antenna.

[0032] In this embodiment, a second L-shaped bending portion facing outward is provided at the bottom of the folded short-circuit metal wall 2, and the folded short-circuit metal wall 2 is fixedly connected to the antenna metal floor 5 via the second L-shaped bending portion. By folding the folded short-circuit metal wall 2, the cross-sectional height of the antenna can be effectively reduced.

[0033] In this embodiment, the metal floor 5 is preferably in a grid shape. The metal floor 5 is located at the bottom of the overall structure. The grid design can effectively reduce the cost and weight of the antenna, while facilitating the installation and movement of the antenna.

[0034] In this embodiment, each U-shaped parasitic metal sheet 4 is preferably provided with two insulating support columns 6, and the material of the insulating support columns 6 is polytetrafluoroethylene. The surface current distribution on the U-shaped parasitic metal sheet 4 is consistent with the current distribution on the antenna surface, which extends the current path of the antenna at low frequencies and expands the bandwidth of the antenna. At the same time, compared with the inverted L-shaped parasitic structure, the surface current distribution of the U-shaped parasitic structure is more concentrated, which can avoid the appearance of large induced currents on the vertical section of the parasitic structure and achieve higher gain.

[0035] Working process and principle: The antenna works in the ultra-short wave frequency band (30–70MHz). When working, the electromagnetic wave is fed into the stepped metal feed line 3 through the coaxial probe, and the feeding is realized by coupling the stepped metal feed line 3 with the rectangular metal sheet 1 and the folded short-circuit metal wall 2. By folding the short-circuit metal wall, the cross-sectional height of the antenna is effectively reduced, and the cross-sectional height of the antenna is only 0.163 wavelengths (center frequency 50MHz, corresponding height is 980mm). The floor of the antenna is gridded. Compared with the complete metal floor, the metal area is reduced by about 82.6%, which reduces the cost and weight of the antenna and facilitates installation and movement. When working, the induced current distribution on the four U-shaped parasitic metal sheets 4 is consistent with the current distribution on the surface of the antenna, thereby extending the current path of the antenna at low frequency and expanding the low-frequency working band of the antenna. At the same time, compared with the inverted L-shaped parasitic structure, the current distribution of the U-shaped parasitic structure is concentrated on the horizontal section of the patch, which can avoid the large induced current on the vertical section of the parasitic structure and improve the gain reduction problem caused by the inverted L-shaped structure.

[0036] like Figure 5As shown, it is the standing wave ratio and gain curve of the antenna. It can be seen from the figure that in the frequency range of 30-70MHz, the standing wave ratio of the antenna is less than 2, the relative bandwidth is greater than 80%, the internal gain of the antenna is greater than 7dBi, and the peak gain reaches 9.25dBi.

[0037] like Figure 6 , 7 As shown in Figures 8 and 9, the directional diagrams of the antenna at different frequencies are shown. It can be seen from the figure that the antenna has directional radiation performance within the working frequency band. It can be seen that the antenna of the present invention has good broadband directional radiation performance and can be applied to ultra-short wave directional communication.

[0038] Finally, it should be noted that the embodiments described are intended to help readers understand the principles of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific statements and embodiments. Based on the specific implementation methods and embodiments of the present invention, all other implementation methods and embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

Claims

1. A broadband low-profile magnetoelectric dipole antenna for ultra-short wave directional communication, characterized in that: It comprises an antenna metal floor (5), a stepped metal feed line (3) and two rectangular metal sheets (1) parallel to the antenna metal floor (5), the two rectangular metal sheets (1) are symmetrically arranged above the antenna metal floor (5), the inner side of each rectangular metal sheet (1) is connected to a folded short-circuit metal wall (2), and the bottom of each folded short-circuit metal wall (2) is fixedly connected to the antenna metal floor (5); The stepped metal feed line (3) is arranged between two rectangular metal sheets (1), one end of the stepped metal feed line (3) is open-circuited, and the other end is connected to the antenna metal floor (5); Two U-shaped parasitic metal sheets (4) are arranged at the outer corners of each rectangular metal sheet (1), and each U-shaped parasitic metal sheet (4) is suspended and fixed below the rectangular metal sheet (1) via a plurality of insulating support columns (6).

2. The broadband low-profile magnetoelectric dipole antenna for ultra-short wave directional communication according to claim 1, characterized in that: The step metal feed line (3) comprises a first folded transmission line (71), a second folded transmission line (72) and a coupling strip line (8) located in the same plane as the rectangular metal sheet (1); one side of the coupling strip line (8) is fixedly connected to the upper side of the first folded transmission line (71); a first L-shaped bending portion is provided at the bottom of the first folded transmission line (71); the first L-shaped bending portion forms an open circuit with the antenna metal floor (5); the other side of the coupling strip line (8) is fixedly connected to the upper side of the second folded transmission line (72); the bottom of the second folded transmission line (72) is provided with an outward bending protrusion; the bending protrusion is fixedly connected to the antenna metal floor (5) through a feeding port (9).

3. The broadband low-profile magnetoelectric dipole antenna for ultra-short wave directional communication according to claim 1, characterized in that: Each of the folded short-circuit metal walls (2) is provided with a strip-shaped slot matching the stepped metal feeder (3), the height of the strip-shaped slot being equal to the height of the stepped metal feeder (3), and the width of the strip-shaped slot being equal to the width of the stepped metal feeder (3).

4. The broadband low-profile magnetoelectric dipole antenna for ultra-short wave directional communication according to claim 1, characterized in that: The rectangular metal sheet (1) and the U-shaped parasitic metal sheet (4) partially overlap in their projections on a horizontal plane.

5. The broadband low-profile magnetoelectric dipole antenna for ultra-short wave directional communication according to claim 1, characterized in that: The bottom of the folded short-circuit metal wall (2) is provided with a second L-shaped bending portion facing outwards, and the folded short-circuit metal wall (2) is fixedly connected to the antenna metal floor (5) via the second L-shaped bending portion.

6. The broadband low-profile magnetoelectric dipole antenna for ultra-short wave directional communication according to claim 1, characterized in that: The metal floor (5) is in a grid shape.

7. The broadband low-profile magnetoelectric dipole antenna for ultra-short wave directional communication according to claim 1, characterized in that: The insulating support column (6) is made of polytetrafluoroethylene.

8. The broadband low-profile magnetoelectric dipole antenna for ultra-short wave directional communication according to claim 1, characterized in that: The rectangular metal sheet (1) and the folded short-circuit metal wall (2) are integrally bent and formed.

9. The broadband low-profile magnetoelectric dipole antenna for ultra-short wave directional communication according to claim 1, characterized in that: The U-shaped parasitic metal sheet (4) is formed by integral bending.

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