A broadband circularly polarized dipole antenna with high front-to-back ratio

Abstract

The utility model relates to the field of dipole antennas, and in particular to a broadband circularly polarized dipole antenna with a high front-to-back ratio, which improves the anti-interference ability of the antenna. The technical solution comprises a PCB circuit board (1), a planar dipole antenna (3), a dielectric substrate (4), a cross-feed balun (5) and a plurality of choke modules, wherein the plurality of choke modules are symmetrically arranged on the PCB circuit board (1), the planar dipole antenna (3) is connected to the plurality of symmetrically arranged choke modules, the cross-feed balun (5) passes through the center of the planar dipole antenna (3) and is connected to the PCB circuit board (1), and the dielectric substrate (4) divides the planar dipole antenna (3) into a plurality of parts. The utility model is applicable to a satellite navigation and positioning system.

Description

Technical Field

[0001] The utility model relates to the field of vibrator antennas, in particular to a broadband circularly polarized vibrator antenna with a high front-to-back ratio. Background Art

[0002] With the continuous improvement of GNSS (Global Navigation Satellite System), the performance requirements for high-precision antenna products are also increasing. In order to meet the needs of positioning equipment to receive satellite signals of different frequency bands of different navigation systems, current antennas generally use traditional microstrip stacked antennas or spiral antennas.

[0003] Microstrip antennas are low in height, but have narrow bandwidth and heavy weight, and the antenna performance is easily affected by the characteristics of the medium itself. The four-arm helical antenna has a compact structure and a wide beam width, but has a narrow bandwidth and a complex feeding network, making it difficult to cover the four major satellite navigation systems at the same time. In addition, traditional microstrip stacked antennas or helical antennas have poor anti-interference capabilities. Utility Model Content

[0004] The utility model aims to overcome the shortcomings of the prior art and provide a broadband circularly polarized dipole antenna with a high front-to-back ratio, thereby improving the anti-interference ability of the antenna.

[0005] The utility model adopts the following technical scheme to achieve the above-mentioned purpose. The utility model provides a broadband circularly polarized dipole antenna with a high front-to-back ratio, including a PCB circuit board 1, a planar dipole antenna 3, a dielectric substrate 4, a cross-feed balun 5 and a plurality of choke modules, wherein the plurality of choke modules are symmetrically arranged on the PCB circuit board 1, the planar dipole antenna 3 is connected to the plurality of symmetrically arranged choke modules, the cross-feed balun 5 passes through the center of the planar dipole antenna 3 and is connected to the PCB circuit board 1, and the dielectric substrate 4 divides the planar dipole antenna 3 into a plurality of parts.

[0006] Furthermore, the cross-feed balun 5 adopts a microstrip balun, which is composed of an inner conductor 6 and an outer conductor 7. The inner conductor 6 is printed on one side of the dielectric substrate, and the outer conductor 7 is printed on the other side of the dielectric substrate 4. The microstrip balun structure improves the flexibility and convenience of the cross-feed balun application.

[0007] Furthermore, the cross-feed balun 5 adopts a coaxial balun, which is mainly composed of an inner conductor 6 and an outer conductor 7, and a circle of dielectric 8 is wrapped between the inner conductor 6 and the outer conductor 7. The circle of dielectric has insulating properties, and the circle of dielectric can prevent the electrical signal from flowing from the center conductor to the outer conductor, and at the same time play a supporting role to ensure that the cable structure forms a stable whole. The coaxial balun improves the anti-interference ability.

[0008] Furthermore, the lower end of the outer conductor 7 is connected to the floor, and the upper end is connected to the planar antenna 3. The vertical section of the inner conductor 6 first passes through one radiating arm of the planar antenna 3, passes through the horizontal section, and then passes through the other radiating arm of the planar antenna 3. The end of the inner conductor 6 is in an open circuit state, and the horizontal sections of the inner conductor 6 and the outer conductor 7 are perpendicular to each other and are not connected.

[0009] Furthermore, the choke module is a choke piece 2-1, and the choke piece 2-1 is a copper-clad FR4 dielectric substrate, and the height and number of the choke piece 2-1 are increased or decreased according to the performance of the broadband circularly polarized dipole antenna with a high front-to-back ratio. In this way, the antenna's ability to resist multipath interference is improved.

[0010] Furthermore, the choke module is a choke post 2-2, which is a metal part, and the height and number of the choke post 2-2 are increased or decreased according to the performance of the broadband circularly polarized dipole antenna with a high front-to-back ratio. In this way, the antenna's ability to resist multipath interference is improved.

[0011] Beneficial effects of the utility model:

[0012] The utility model loads a choke structure around the planar vibrator antenna, which can greatly improve the front-to-back ratio of the antenna without damaging the antenna performance. The choke structure is composed of a dielectric substrate and an irregular copper-clad circuit, and can also be composed of a metal structure of any shape, which is symmetrically placed around the planar vibrator. The capacitive coupling with the vibrator antenna is increased, the electric field parallel to the PCB circuit board and the magnetic field perpendicular to the PCB circuit board are suppressed, and the anti-multipath interference capability of the vibrator antenna is improved. The cross-feed balun converts the unbalanced signal into a balanced signal, realizes the vibrator feeding of the symmetrical structure, and avoids the shape distortion of the antenna radiation pattern. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a top view of a broadband circularly polarized dipole antenna with a high front-to-back ratio provided by an embodiment of the utility model;

[0014] Figure 2 This is a front view of a broadband circularly polarized dipole antenna with a high front-to-back ratio provided by an embodiment of the utility model;

[0015] Figure 3 This is a cross-sectional view of a broadband circularly polarized dipole antenna with a high front-to-back ratio provided by an embodiment of the utility model;

[0016] Figure 4 1 is a schematic diagram of the structure of a cross-feed balun provided by an embodiment of the utility model, wherein (a) represents a front view of a dielectric substrate, and (b) represents a back view of the dielectric substrate;

[0017] Figure 5It is a top view of another broadband circularly polarized dipole antenna with a high front-to-back ratio provided by an embodiment of the utility model;

[0018] Figure 6 It is a front view of another broadband circularly polarized dipole antenna with a high front-to-back ratio provided by an embodiment of the utility model;

[0019] Figure 7 This is a cross-sectional view of another broadband circularly polarized dipole antenna with a high front-to-back ratio provided by an embodiment of the utility model;

[0020] Figure 8 It is a front view of another cross-feed balun structure provided by an embodiment of the utility model;

[0021] Fig. 9 is a top view of another cross-feed balun structure provided by an embodiment of the utility model;

[0022] In the accompanying drawings, 1 is a PCB circuit board, 2-1 is a choke, 2-2 is a choke column, 3 is a planar oscillator antenna, 4 is a dielectric substrate, 5 is a cross-fed balun, 6 is an inner conductor, 7 is an outer conductor, and 8 is a medium between the inner conductor and the outer conductor of the coaxial balun. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present utility model clearer, the technical solution in the embodiments of the present utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the present utility model.

[0024] like Figure 1 As shown, the utility model provides a broadband circularly polarized dipole antenna with a high front-to-back ratio, comprising a PCB circuit board 1, a planar dipole antenna 3, a dielectric substrate 4, a cross-fed balun 5 and a plurality of choke modules, wherein the plurality of choke modules are symmetrically arranged on the PCB circuit board 1, the planar dipole antenna 3 is connected to the plurality of symmetrically arranged choke modules, the cross-fed balun 5 passes through the center of the planar dipole antenna 3 and is connected to the PCB circuit board 1, and the dielectric substrate 4 divides the planar dipole antenna 3 into four parts.

[0025] like Figure 4 As shown, the cross-feed balun 5 adopts a microstrip line balun, which is composed of an inner conductor 6 and an outer conductor 7. The inner conductor 6 is printed on one side of the dielectric substrate, and the outer conductor 7 is printed on the other side of the dielectric substrate.

[0026] like Figure 8 , Fig. 9As shown, the cross-feed balun 5 can also use a coaxial balun, which is mainly composed of an inner conductor 6 (core) and an outer conductor 7 (braided layer), and a circle of dielectric 8 is wrapped between the inner conductor 6 and the outer conductor 7. The circle of dielectric has insulating properties, and the circle of dielectric can prevent the electrical signal from flowing from the center conductor to the outer conductor, and at the same time play a supporting role to ensure that the cable structure forms a stable whole. The coaxial balun improves the anti-interference ability.

[0027] like Figure 8 As shown, the lower end of the outer conductor 7 is connected to the floor, and the upper end where the core is exposed is connected to the planar antenna 3. The vertical section of the inner conductor 6 first passes through one radiating arm of the planar antenna 3, and then passes through the horizontal section and then passes through the other radiating arm of the planar antenna 3. The end of the inner conductor 6 is in an open circuit state, and the horizontal sections of the inner conductor 6 and the outer conductor 7 are perpendicular to each other and are not connected.

[0028] like Figure 2 , Figure 3 As shown, the choke module is a choke piece 2-1, and the choke piece 2-1 is evenly placed around the planar antenna 3. The choke piece 2-1 is a copper-clad FR4 dielectric substrate. The height and number of the choke piece 2-1 are increased or decreased according to the performance of the broadband circularly polarized antenna with a high front-to-back ratio. The choke piece 2-1 is connected to the planar antenna 3 through the connection hole of the planar antenna 3. In this embodiment, the dielectric substrate can also be any high-frequency plate material, and the shape of the copper cladding can be rectangular or polygonal.

[0029] like Figure 5 , Figure 6 , Figure 7 As shown, the choke module is a choke post 2-2, which is evenly placed around the planar dipole antenna 3. The choke post 2-2 is a metal part, and the height and number of the choke post 2-2 are increased or decreased according to the performance of the broadband circularly polarized dipole antenna with a high front-to-back ratio. The choke post 2-2 is connected to the planar dipole antenna 3 through the connection hole of the planar dipole antenna 3.

[0030] The above is only a preferred embodiment of the utility model. It should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.

Claims

1. A broadband circularly polarized dipole antenna with a high front-to-back ratio, characterized in that: The invention comprises a PCB circuit board (1), a planar dipole antenna (3), a dielectric substrate (4), a cross-feed balun (5) and a plurality of choke modules, wherein the plurality of choke modules are symmetrically arranged on the PCB circuit board (1), the planar dipole antenna (3) is connected to the plurality of symmetrically arranged choke modules, the cross-feed balun (5) passes through the center of the planar dipole antenna (3) and is connected to the PCB circuit board (1), and the dielectric substrate (4) divides the planar dipole antenna (3) into a plurality of parts.

2. The broadband circularly polarized dipole antenna with high front-to-back ratio according to claim 1, characterized in that: The cross-feed balun (5) adopts a microstrip line balun and is composed of an inner conductor (6) and an outer conductor (7). The inner conductor (6) is printed on one side of a dielectric substrate, and the outer conductor (7) is printed on the other side of the dielectric substrate (4).

3. The broadband circularly polarized dipole antenna with high front-to-back ratio according to claim 1, characterized in that: The cross-feed balun (5) adopts a coaxial line balun, which is mainly composed of an inner conductor (6) and an outer conductor (7), and a circle of dielectric (8) is wrapped between the inner conductor (6) and the outer conductor (7).

4. The broadband circularly polarized dipole antenna with high front-to-back ratio according to claim 3, characterized in that: The lower end of the outer conductor (7) is connected to the floor, and the upper end is connected to the planar dipole antenna (3). The vertical section of the inner conductor (6) first passes through one radiating arm of the planar dipole antenna (3), passes through the horizontal section, and then passes through the other radiating arm of the planar dipole antenna (3). The end of the inner conductor (6) is in an open circuit state, and the horizontal sections of the inner conductor (6) and the outer conductor (7) are perpendicular to each other and are not connected.

5. The broadband circularly polarized dipole antenna with high front-to-back ratio according to claim 1, characterized in that: The choke module is a choke piece (2-1), and the choke piece (2-1) is a copper-clad FR4 dielectric substrate. The height and number of the choke pieces (2-1) are increased or decreased according to the performance of a broadband circularly polarized dipole antenna with a high front-to-back ratio.

6. The broadband circularly polarized dipole antenna with high front-to-back ratio according to claim 1, characterized in that: The choke module is a choke column (2-2), and the choke column (2-2) is a metal part. The height and number of the choke columns (2-2) are increased or decreased according to the performance of a broadband circularly polarized dipole antenna with a high front-to-back ratio.

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