A series-fed microstrip antenna

Abstract

The present invention is applicable to the technical field of radar antennas, and provides a series-fed microstrip antenna, comprising: a series-fed antenna, a first coupling antenna, and a second coupling antenna arranged on the front of a substrate, a grounded metal plate arranged on the back of the substrate, and a first grounding hole and a second grounding hole penetrating the substrate; wherein the first coupling antenna and the second coupling antenna are arranged in parallel on both sides of the series-fed antenna, and are respectively at a first preset distance and a second preset distance from the series-fed antenna; the first coupling antenna and the second coupling antenna are respectively connected to the grounded metal plate through the first grounding hole and the second grounding hole. The present invention can change the maximum beam pointing direction of the series-fed antenna, widen the beam width by 3db, and will not generate additional insertion loss, thereby effectively improving the radiation efficiency of the antenna.

Description

Technical Field

[0001] The invention belongs to the technical field of radar antennas, and in particular relates to a series-fed microstrip antenna. Background Art

[0002] Compared with traditional microstrip antennas, series-fed microstrip antennas have the characteristics of compact structure, easy integration, and easier to achieve narrow beam and high gain, becoming a research hotspot in the field of radar antennas.

[0003] The traditional series-fed microstrip antenna has only one antenna unit, so its maximum horizontal beam pointing is fixed, and the 3dB beam width is about 70° to 80°. The existing technology usually uses multiple series-fed microstrip antennas to combine into an array antenna, and combines a relatively complex feeding network to change the maximum beam pointing of the series-fed microstrip antenna and widen the 3dB beam width, but this method will generate additional insertion loss and reduce the radiation efficiency of the antenna. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a series-fed microstrip antenna to solve the problem that the series-fed microstrip antenna in the prior art easily generates additional insertion loss and has low radiation efficiency.

[0005] An embodiment of the present invention provides a series-fed microstrip antenna, comprising:

[0006] A substrate, a series-fed antenna, a first coupling antenna, a first grounding hole, a second coupling antenna, a second grounding hole and a grounding metal plate; wherein the series-fed antenna, the first coupling antenna and the second coupling antenna are arranged on the front side of the substrate, the grounding metal plate is arranged on the back side of the substrate, and the first grounding hole and the second grounding hole penetrate the substrate; the first coupling antenna and the second coupling antenna are arranged in parallel on both sides of the series-fed antenna; the first coupling antenna and the series-fed antenna are separated by a first preset distance, and the second coupling antenna and the series-fed antenna are separated by a second preset distance; the first coupling antenna and the second coupling antenna are connected to the grounding metal plate through the first grounding hole and the second grounding hole, respectively.

[0007] Optionally, the first preset distance is equal to the second preset distance, or the first preset distance is not equal to the second preset distance.

[0008] Optionally, the first coupling antenna, the second coupling antenna and the series-fed antenna have the same structure, or the first coupling antenna, the second coupling antenna and the series-fed antenna have different structures.

[0009] Optionally, if the first coupling antenna, the second coupling antenna and the series-fed antenna have the same structure, the series-fed antenna, the first coupling antenna and the second coupling antenna all include a plurality of patch units connected in sequence through a feeding microstrip line, and the positions of each patch unit of the first coupling antenna and the second coupling antenna correspond one-to-one to the positions of each patch unit of the series-fed antenna.

[0010] Optionally, the distribution forms of the patch units of the series-fed antenna, the first coupling antenna, and the second coupling antenna are all Taylor distribution.

[0011] Optionally, polarization modes of the patch units of the series-fed antenna, the first coupling antenna, and the second coupling antenna include horizontal polarization, vertical polarization, or circular polarization.

[0012] Optionally, the first grounding hole is one quarter wavelength away from the first patch unit; wherein the first patch unit is the patch unit in the first coupling antenna that is closest to the first grounding hole.

[0013] Optionally, the second grounding hole is one quarter wavelength away from the second patch unit; wherein the second patch unit is the patch unit in the second coupling antenna that is closest to the second grounding hole.

[0014] Optionally, the patch unit is a rectangular metal patch.

[0015] Optionally, the material of the substrate is high-frequency microwave plate.

[0016] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0017] The present invention sets two grounded coupling antennas in parallel on both sides of the series-fed antenna, uses the coupling between the antennas to broaden the beam width by 3db, and changes the distance between the first coupling antenna, the second coupling antenna and the series-fed antenna to change the mutual electromagnetic coupling amount, thereby achieving a change in the maximum beam direction. Compared with array antennas with complex feeding networks, the present invention does not introduce additional feeding networks, does not generate additional insertion losses, and effectively improves the radiation efficiency of the antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art 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 paying creative labor.

[0019] Figure 1 It is a schematic diagram of the structure of a series-fed microstrip antenna provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0021] In order to illustrate the technical solution of the present invention, a specific embodiment is provided below for illustration.

[0022] See also Figure 1 , which shows a schematic diagram of the structure of a series-fed microstrip antenna provided by an embodiment of the present invention, including a main view Figure 1 a. Side view Figure 1 b and side view Figure 1 c. Specifically, it may include:

[0023] The substrate 10 , the series-fed antenna 11 , the first coupling antenna 12 , the first grounding hole 14 , the second coupling antenna 13 , the second grounding hole 15 and the grounding metal plate 16 .

[0024] The series-fed antenna 11, the first coupling antenna 12 and the second coupling antenna 13 are arranged on the front surface of the substrate 10, the first coupling antenna 12 and the second coupling antenna 13 are arranged in parallel on both sides of the series-fed antenna 11, and the first coupling antenna 12 is at a first preset distance from the series-fed antenna 11, and the second coupling antenna 13 is at a second preset distance from the series-fed antenna 11. A first grounding hole 14 is arranged at one end of the first coupling antenna 12, and the first grounding hole 14 passes through the substrate 10 and is connected to the grounding metal plate 16 on the back of the substrate 10; similarly, a second grounding hole 15 is arranged at one end of the second coupling antenna 13, and the second grounding hole 15 passes through the substrate 10 and is connected to the grounding metal plate 16 on the back of the substrate 10.

[0025] In the embodiment of the present invention, the grounding metal plate 16 completely covers the back surface of the substrate 10. By introducing the grounding point, the coupling effect of nearby objects such as the antenna cover can be reduced, thereby increasing the stability of the antenna radiation characteristics.

[0026] Optionally, the first preset distance is equal to the second preset distance, or the first preset distance is not equal to the second preset distance.

[0027] In the embodiment of the present invention, the first preset distance and the second preset distance may be set equal, or may be set unequal. When the first preset distance and the second preset distance are equal, only the 3db beam width is widened, and the maximum beam pointing is not changed. In practical applications, the first preset distance and the second preset distance may be set according to the required 3db beam width.

[0028] When the first preset distance is not equal to the second preset distance, since the coupling antenna acts as a director when it is close to the series-fed antenna (less than a quarter wavelength), and acts as a reflector when it is far away from the series-fed antenna (greater than a quarter wavelength), the first preset distance and the second preset distance can be set according to the required pointing angle to achieve the effect of changing the maximum beam pointing and widening the 3db beam width. In an embodiment of the present invention, the maximum beam can be pointed to 40°, and the 3db beam width can be widened to 120°.

[0029] Optionally, the first coupling antenna, the second coupling antenna and the series-fed antenna have the same structure, or the first coupling antenna, the second coupling antenna and the series-fed antenna have different structures.

[0030] The structures of the first coupling antenna and the second coupling antenna on both sides of the series-fed antenna may be the same as or different from the series-fed antenna, and the first coupling antenna and the second coupling antenna may also be the same or different. In an embodiment of the present invention, by setting the first coupling antenna and the second coupling antenna to have the same structure as the series-fed antenna, it is possible to more conveniently adjust the coincidence of the resonance points of the coupling antenna and the series-fed antenna, and then widen the beam width by 3db through the coupling effect between the coupling antenna and the series-fed antenna.

[0031] Optionally, if the first coupling antenna, the second coupling antenna and the series-fed antenna have the same structure, the series-fed antenna, the first coupling antenna and the second coupling antenna all include a plurality of patch units connected in sequence through a feeding microstrip line, and the positions of each patch unit of the first coupling antenna and the second coupling antenna correspond one-to-one to the positions of each patch unit of the series-fed antenna.

[0032] In the embodiment of the present invention, the design of the series-fed antenna 11 adopts 8 patch units, each of which is connected in sequence through a feeding microstrip line 17. The polarization mode of the patch unit can be horizontal polarization, vertical polarization or circular polarization, and Taylor distribution is used in distribution to reduce the sidelobe level of the beam in the direction of the antenna array. The number, polarization mode and distribution form of the patch units of the first coupling antenna 12 and the second coupling antenna 13 are completely consistent with those of the series-fed antenna 11, and the positions of each patch unit of the first coupling antenna 12 and the second coupling antenna 13 correspond one-to-one to the positions of each patch unit of the series-fed antenna 11.

[0033] Optionally, in the first coupling antenna 12, the first grounding hole 14 is one quarter wavelength away from the first patch unit 18 closest thereto; and in the second coupling antenna 13, the second grounding hole 15 is one quarter wavelength away from the second patch unit 19 closest thereto.

[0034] Optionally, in the embodiment of the present invention, the patch unit may be a rectangular metal patch.

[0035] Optionally, in the embodiment of the present invention, the substrate 10 may be made of a high-frequency microwave plate material with stable electromagnetic properties.

[0036] From the above, it can be seen that the present invention can achieve the change of the maximum beam direction by setting two grounded coupling antennas in parallel on both sides of the series-fed antenna, using the coupling between the antennas to widen the beam width by 3db, and changing the distance between the first coupling antenna, the second coupling antenna and the series-fed antenna to change the mutual electromagnetic coupling amount. And compared with the array antenna with a complex feeding network, the present invention does not introduce an additional feeding network, does not generate additional insertion loss, and effectively improves the radiation efficiency of the antenna.

[0037] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0038] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A series-fed microstrip antenna, characterized in that: include: A substrate, a series-fed antenna, a first coupling antenna, a first grounding hole, a second coupling antenna, a second grounding hole, and a grounding metal plate; The series-fed antenna, the first coupling antenna, and the second coupling antenna are arranged on the front side of the substrate, the grounding metal plate is arranged on the back side of the substrate, and the first grounding hole and the second grounding hole penetrate the substrate; The first coupling antenna and the second coupling antenna are arranged in parallel on both sides of the series-fed antenna; The first coupling antenna is at a first preset distance from the series-fed antenna, and the second coupling antenna is at a second preset distance from the series-fed antenna; the first coupling antenna and the second coupling antenna are connected to the grounding metal plate through a first grounding hole and a second grounding hole, respectively.

2. The series-fed microstrip antenna according to claim 1, characterized in that: The first preset distance is equal to the second preset distance, or the first preset distance is not equal to the second preset distance.

3. The series-fed microstrip antenna according to claim 1, characterized in that: The first coupling antenna, the second coupling antenna and the series-fed antenna have the same structure, or the first coupling antenna, the second coupling antenna and the series-fed antenna have different structures.

4. The series-fed microstrip antenna according to claim 3, characterized in that: If the first coupling antenna, the second coupling antenna and the series-fed antenna have the same structure, the series-fed antenna, the first coupling antenna and the second coupling antenna all include a plurality of patch units connected in sequence through a feeding microstrip line, and the positions of the patch units of the first coupling antenna and the second coupling antenna correspond one-to-one to the positions of the patch units of the series-fed antenna.

5. The series-fed microstrip antenna according to claim 4, characterized in that: The distribution forms of the patch units of the series-fed antenna, the first coupling antenna and the second coupling antenna are all Taylor distribution.

6. The series-fed microstrip antenna according to claim 4, characterized in that: The polarization modes of the patch units of the series-fed antenna, the first coupling antenna and the second coupling antenna include horizontal polarization, vertical polarization or circular polarization.

7. The series-fed microstrip antenna according to claim 4, characterized in that: The first grounding hole is one quarter wavelength away from the first patch unit; wherein the first patch unit is the patch unit in the first coupling antenna that is closest to the first grounding hole.

8. The series-fed microstrip antenna according to claim 4, characterized in that: The second grounding hole is one quarter wavelength away from the second patch unit; wherein the second patch unit is the patch unit in the second coupling antenna that is closest to the second grounding hole.

9. The series-fed microstrip antenna according to any one of claims 4 to 8, characterized in that: The patch unit is a rectangular metal patch.

10. The series-fed microstrip antenna according to claim 1, characterized in that: The material of the substrate is high-frequency microwave plate.

Images