An extremely small diameter broadband dipole omnidirectional antenna

Abstract

The present invention discloses an extremely small diameter broadband dipole omnidirectional antenna, belonging to the field of antenna technology. It comprises a printed dipole antenna, a fiberglass antenna cover, a metal mounting base, a dielectric support block, a 50Ω coaxial feeder and other components. The technical solution of the present invention solves the technical problem that the antenna performance indicators are limited under extremely small diameter dimensions. Through a special printed dipole antenna and its feeding method, the antenna bandwidth is effectively increased, and it can be directly fed with a 50Ω coaxial feeder. The relative bandwidth can reach 27.89%, which is much higher than the relative bandwidth of an ordinary dipole. The antenna pattern has good consistency and small non-circularity within the working frequency band. The printed dipole antenna and its feeding method in the present invention have the characteristics of simple structure, low cost, light weight, easy mass production, and easy conformal with the antenna cover or other carrier platforms.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to an extremely small diameter broadband dipole omnidirectional antenna. Background Art

[0002] In the field of UAV measurement and control, the antenna is required to have the ability to radiate and receive in different directions at low elevation angles. Therefore, omnidirectional antennas are often the best choice. Omnidirectional antennas have full coverage in the horizontal plane and appear as beams with a certain width in the vertical plane.

[0003] Omnidirectional antennas are generally divided into three types: horizontally polarized omnidirectional antennas, vertically polarized omnidirectional antennas, and circularly polarized omnidirectional antennas. Omnidirectional antennas mainly include helical antennas, waveguide slot antennas, monopole antennas, dipole antennas, etc. With the development of modern communication technology, antennas are required to have wide bandwidths while being more and more miniaturized and conformal. This can effectively reduce the RCS of the entire platform, increase platform mobility, and improve antenna concealment. In addition, due to the limitations of antenna installation space, higher requirements are often placed on the antenna, especially in extremely small sizes, where the antenna options are often less. Summary of the invention

[0004] In view of this, the present invention provides a very small diameter broadband dipole omnidirectional antenna. The present invention has a simple structure, low cost, light weight, easy mass production, easy conformity with the radome or other carrier platform, and the antenna direction within the working frequency band is Figure 1 Good consistency.

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

[0006] An extremely small diameter broadband dipole omnidirectional antenna, comprising a printed dipole antenna, and also comprising a fiberglass antenna cover, a metal mounting base, a dielectric support block and a 50Ω coaxial feed line;

[0007] The printed dipole antenna comprises a printed board, a left radiating element and a right radiating element. The printed board is in the shape of a long strip. The left radiating element is located in the middle of the front side of the printed board, and the right radiating element is located at the end of the back side of the printed board. The right radiating element is provided with a metallized hole, and the left radiating element extends to one side with a microstrip transmission line, and the end of the microstrip transmission line is connected to the metallized hole. The microstrip transmission line is also provided with a matching branch perpendicular to it.

[0008] The metal mounting base is installed on the bottom plate of the fiberglass antenna cover, and forms a closed space with the fiberglass antenna cover; the printed dipole antenna and the dielectric support block are both located in the closed space, wherein the bottom of the dielectric support block is fixed to the metal mounting base; the printed dipole antenna is fixed to the upper surface of the dielectric support block; one end of the 50Ω coaxial feeder is located in the closed space, its outer conductor is connected to the right radiating element, and the inner conductor is connected to the left radiating element through the metallized hole; the other end of the 50Ω coaxial feeder passes through the dielectric support block and the metal mounting base and is connected to the SMA-WJ type connector.

[0009] Furthermore, the fiberglass antenna cover and the metal mounting base are threadedly connected.

[0010] The beneficial effects of the above technical solution of the present invention are:

[0011] 1. The present invention solves the technical problem of limited antenna performance indicators under extremely small diameter size. Through a special printed dipole antenna and its feeding method, the antenna bandwidth is effectively increased. It can be directly fed with a 50Ω coaxial feeder. The relative bandwidth can reach 27.89%, which is much higher than the relative bandwidth of ordinary dipoles. The antenna direction within the working frequency band is Figure 1 Good consistency and small out-of-roundness.

[0012] 2. The printed dipole antenna and its feeding method in the present invention have the characteristics of simple structure, low cost, light weight, easy mass production, and easy conformity with the antenna cover or other carrier platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0014] Figure 2 for Figure 1 Schematic diagram of the upper structure of the printed circuit board;

[0015] Figure 3 for Figure 2 Schematic diagram of the lower structure of the printed circuit board;

[0016] Figure 4 for Figure 1 Schematic diagram of the feeding structure at the middle feeding point;

[0017] Figure 5 is the voltage standing wave ratio of the embodiment of the present invention.

[0018] Figure 6 These are the directional diagrams of the frequencies 1.45 GHz, 1.70 GHz, and 1.92 GHz according to an embodiment of the present invention.

[0019] In the figure: 1- printed dipole antenna 2- fiberglass antenna cover 3- metal mounting base 4- dielectric support block 5- 50Ω coaxial feed line 6- printed circuit board 7- left radiator 8- right radiator 9- feeding point DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] A very small diameter broadband dipole omnidirectional antenna comprises a printed dipole antenna, a fiberglass antenna cover, a metal mounting base, a dielectric support block, and a 50Ω coaxial feeder. The printed dipole antenna is placed inside the fiberglass antenna cover.

[0023] The two half-wave radiating oscillators are placed in parallel, on the front and back sides of the printed circuit board, and the lengths of the two half-wave radiating oscillators are the same.

[0024] Feeding method: One radiating oscillator is connected to the inner core of a 50Ω coaxial feeder at the feeding point through a microstrip transmission line with matching branches and vias, and the other radiating oscillator is connected to the metal sheath of the 50Ω coaxial feeder.

[0025] A radiating arm of the printed dipole antenna is used as the radiation ground. The feeding position can be selected at any point on the radiation ground. The purpose of impedance matching is achieved by adjusting the size of the microstrip transmission line and matching branches.

[0026] The fiberglass antenna cover can be a dielectric cover in a cylindrical or other shapes.

[0027] Used for impedance matching, it can be in the form of a cable or a connector.

[0028] The following is a more specific embodiment:

[0029] Reference Figures 1 to 4 This embodiment includes a printed dipole antenna 1, a fiberglass antenna cover 2, a metal mounting base 3, a dielectric support block 4, and a 50Ω coaxial feed line 5.

[0030] Furthermore, the printed dipole antenna comprises a printed board 6 , a left radiating element 7 , a right radiating element 8 , and the feeding position of the coaxial line is located at a feeding point 9 .

[0031] Furthermore, the left radiating element 7 and the right radiating element 8 are respectively located on the front and back sides of the printed circuit board 6, and the feeding point 9 is located on the back side of the right radiating element 8. The feeding point 9 is connected to the radiating element 7 through a metallized hole through a section of microstrip transmission line. There is a branch on the transmission line, which forms a "cross" structure with the transmission line, and forms a printed dipole antenna 1 with the right radiating element 8.

[0032] Furthermore, the maximum diameter of the printed circuit board 6 is the same as the diameter of the bottom circular hole of the glass fiber reinforced plastic radome 2 , so the printed circuit board 6 can just pass through the circular hole and be placed in the glass fiber reinforced plastic radome 2 .

[0033] Furthermore, the metal mounting base 3 is mounted on the bottom of the FRP radome 2 . The bottom of the FRP radome 2 is threaded, and the metal mounting base 3 is fixed to the FRP radome 2 via the thread.

[0034] Furthermore, the dielectric support block 4 has a small hole at its center for passing and fixing a 50Ω coaxial feed line. The dielectric support block 4 can just be stuck inside the metal mounting base 3 , and plays a role in fixing and supporting the printed circuit board 6 .

[0035] Furthermore, the tail end of the 50Ω coaxial feeder is a SMA-WJ type connector, the metal sheath at the other end of the feeder is welded to the surface of the right radiating oscillator 8, and the inner core is welded to the left radiating oscillator 7 through a metallized through hole. Figure 4 shown.

[0036] Figure 1 This is a structural diagram of an extremely small diameter broadband dipole omnidirectional antenna of the present embodiment. The present embodiment proposes a structural diagram of an extremely small diameter broadband dipole omnidirectional antenna device and its feeding method, including a printed dipole antenna 1, a fiberglass antenna cover 2, a metal mounting base 3, a dielectric support block 4, and a 50Ω coaxial feed line 5.

[0037] In this embodiment, if Figure 2 and Figure 3 They are the upper structure diagram of the printed board and the lower structure diagram of the printed board. Printed board 6 is a 1mm thick NY9220 (IM) printed board with a dielectric constant of 2.2. The maximum diameter of printed board 6 is 5mm, the minimum diameter is 2.2mm, and the length is 93mm.

[0038] In this embodiment, the left radiating oscillator 7 and the right radiating oscillator 8 are both 32 mm long, which is less than a quarter wavelength of the high frequency, and are respectively located on the front and back sides of the printed circuit board 6. The microstrip transmission line is 1 mm wide and 20 mm long. One end of the microstrip transmission line is connected to the left radiating oscillator 7, and the other end is connected to the feeding point 9. The matching branch is located at the center of the microstrip transmission line, crosses the microstrip transmission line, and is integrated with the left radiating oscillator 7. The position and size of the matching branch and the size of the microstrip transmission line can be adjusted through parameter optimization.

[0039] In this embodiment, the maximum inner diameter of the bottom circular hole of the glass fiber antenna cover 2 is 5.5 mm, so the selected antenna diameter must be less than 5.5 mm. Conventional antenna forms cannot achieve broadband radiation at this small size, so the maximum diameter of the printed circuit board is selected to be 5 mm.

[0040] In this embodiment, the lengths of the left radiating element 7 and the right radiating element 8 are related to the impedance and standing wave of the antenna device, and can be adjusted by parameter optimization. The obtained voltage standing wave ratio diagram is shown in FIG. Figure 5 It can be seen that the voltage standing wave ratio of the antenna is less than 2.0 in the frequency bandwidth of 1.45GHz-1.92GHz, and the relative bandwidth can reach 27.89%, which is much higher than the relative bandwidth of ordinary dipoles, and this is still under the premise of extremely small diameter.

[0041] In this embodiment, see Figure 6 , which are the directional patterns of the antenna at 1.45GHz, 1.70GHz, and 1.92GHz. It can be seen that the operating frequency coverage of the antenna is 1.45GHz-1.92GHz, and the gain in the entire bandwidth is greater than 1.72dBi. The directional pattern can achieve good omnidirectional characteristics within the bandwidth.

[0042] It is worth mentioning that in the above embodiment, if the diameter of the antenna dipole becomes larger, the working bandwidth of the antenna will also become wider.

[0043] In addition, in the above embodiment, the position of the feeding point 9 can be moved left and right along with the microstrip transmission line, and the position can be adjusted to fit the actual installation environment.

[0044] This embodiment does not describe in detail some of the techniques that belong to those skilled in the art.

[0045] The above are only preferred embodiments of the present invention, which are intended to further illustrate the present invention, but not to limit it. Any simple replacement based on the contents disclosed in the above text and drawings is within the scope of protection of this patent.

Claims

1. A very small diameter broadband dipole omnidirectional antenna, including a printed dipole antenna, characterized in that: It also includes a fiberglass radome, a metal mounting base, a dielectric support block, and a 50Ω coaxial feed line; The printed dipole antenna comprises a printed board, a left radiating element and a right radiating element. The printed board is in the shape of a long strip. The left radiating element is located in the middle of the front side of the printed board, and the right radiating element is located at the end of the back side of the printed board. The right radiating element is provided with a metallized hole, and the left radiating element extends to one side with a microstrip transmission line, and the end of the microstrip transmission line is connected to the metallized hole. The microstrip transmission line is also provided with a matching branch perpendicular to it. The metal mounting base is mounted on the bottom plate of the FRP radome, and forms a closed space with the FRP radome; the printed dipole antenna and the dielectric support block are both located in the closed space, wherein the bottom of the dielectric support block is fixed to the metal mounting base; the printed dipole antenna is fixed to the upper surface of the dielectric support block; one end of the 50Ω coaxial feeder is located in the closed space, and its outer conductor is connected to the right radiating element, and the inner conductor is connected to the left radiating element through the metallized hole; the other end of the 50Ω coaxial feeder passes through the dielectric support block and the metal mounting base and is connected to the SMA-WJ type connector; The printed circuit board is 1mm thick NY9220 printed board with a dielectric constant of 2.

2.

2. The extremely small diameter broadband dipole omnidirectional antenna according to claim 1, characterized in that: The fiberglass antenna cover is threadedly connected to the metal mounting base.

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