A dual-band microstrip antenna with wide fan beam and rectangular beam

Abstract

The present invention discloses a dual-band microstrip antenna with a wide fan beam and a rectangular beam, comprising a first metal patch, an insulating dielectric substrate, a second metal patch, a microstrip transmission line, and a metal via. The first metal patch and the microstrip transmission line are both located on the first surface of the insulating dielectric substrate. One side of the microstrip transmission line is connected to the first metal patch, and the other side serves as the antenna feed end for signal input. A metal via is provided on the first metal patch to short-circuit the first metal patch and the ground plane. The second metal patch is covered on the second surface of the insulating dielectric substrate. The microstrip antenna device of the present invention has a low profile, compact size, and maintains wide azimuth coverage of far-field radiation in two frequency bands, exhibiting excellent wide coverage, high resolution, and high gain performance.

Description

Technical Field

[0001] The present invention relates to a microstrip antenna in the field of wireless communications, in particular to a low-profile dual-band microstrip antenna with a wide fan beam and a rectangular beam. Background Art

[0002] With the rapid development of modern wireless communications, the requirements for dual-band antennas in modern wireless communications are becoming increasingly higher. Dual-band and multi-band antennas have the advantages of compact technology, high integration, and low cost, and have become the development trend of future communications.

[0003] In recent years, mobile communications, broadcasting, navigation, remote telemetry, and radar systems have gradually become ubiquitous in modern applications. These applications are creating demands for adapting to new systems and wide beamwidth antennas. The signal coverage area of ​​a wireless communication system is closely related to the beam pattern characteristics of its antenna components. Wide sector beams offer a wide azimuth beamwidth and significant advantages in wide coverage. This is highly desirable for point-to-multipoint wireless links, as they provide an ideal wireless video surveillance camera solution for campus buildings, remote facilities, security systems, and access control systems.

[0004] The existing technology, "24 GHz Horizontally Polarized Automotive Antenna Arrays with Wide Fan Beam and High Gain," uses multiple patches to form an antenna array, creating a wide-beam radiation pattern on a large metal surface to expand the beamwidth. However, the large number of elements significantly increases the antenna size. In "A Wide-Angle E-Plane Scanning Linear Array Antenna with Wide Beam Elements," vertical metal walls are added to generate vertical induced currents. However, the introduction of these metal walls increases the height of these antennas, thereby destroying the low-profile characteristics of the planar antennas.

[0005] Microstrip antennas are widely used in many array antennas due to their small size, light weight, and ease of construction. However, conventional microstrip antennas have an E-plane beamwidth of approximately 90° and an H-plane beamwidth of approximately 80°. Their gain rapidly decreases at low elevation angles, making them difficult to meet the requirements of wide-angle scanning phased array antennas. Therefore, widening the beamwidth and increasing the gain without sacrificing other performance characteristics is a difficult challenge and a key issue in microstrip antenna research. Summary of the Invention

[0006] The purpose of the present invention is to provide a microstrip antenna that can provide a wide azimuth beam width and maintain wide azimuth coverage in a wireless communication system. The present invention analyzes the far-field radiation characteristics of the antenna without increasing the space occupied by the antenna unit, thereby achieving an expansion of the beam width and improving the gain performance and miniaturization characteristics.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A dual-band microstrip antenna with a wide fan beam and a rectangular beam comprises a first metal patch, an insulating dielectric substrate, a second metal patch, a microstrip transmission line, and a metal through-hole. The first metal patch and the microstrip transmission line are both located on the first surface of the insulating dielectric substrate. One side of the microstrip transmission line is connected to the first metal patch, and the other side serves as the antenna feed end for signal input. A metal through-hole is provided on the first metal patch to short-circuit the first metal patch and a ground plate. The second metal patch covers the second surface of the insulating dielectric substrate.

[0009] In some embodiments, the first metal patch includes a radiation patch, a metal strip and a short microstrip line; the radiation patch is a rectangular patch, and a symmetrically arranged groove is cut in the middle of the upper and lower long edges of the radiation patch; a metal strip parallel to the long edge is provided on the outer side of the upper and lower long sides of the radiation patch; the short microstrip line connects the metal strip and the radiation patch.

[0010] In some embodiments, two metal strips are provided on the outer sides of the upper and lower long sides of the radiation patch, with a gap between the two metal strips on the same side; each metal strip is connected to the radiation patch through two short microstrip lines arranged at intervals and in parallel.

[0011] In some embodiments, the four metal strips are symmetrical about the center of the radiating patch.

[0012] In some embodiments, the outer wide side of the metal strip is flush with the outer wide side of the radiation patch, and the inner wide side of the metal strip is located between the center line of the long side of the radiation patch and the wide side of the groove; one of the short microstrip lines is connected to the long side of the metal strip along the wide side of the groove, and the other short microstrip line is connected to the long side of the metal strip near the wide side of the radiation patch.

[0013] In some embodiments, in order to generate resonance at a desired frequency and improve impedance matching, a metal through-hole is loaded at each of the outermost corners of the four metal strips to short-circuit the first metal patch and the ground plane.

[0014] In some embodiments, in order to achieve a rectangular radiation beam, two slits symmetrical about the center line of the long side of the radiation patch are etched on the radiation patch.

[0015] In some embodiments, a metal through hole is loaded on one side of each slot close to the center of the radiation patch to short-circuit the first metal patch and the ground plate.

[0016] In some embodiments, the length of the first metal patch is 60 mm and the width is 44 mm; the length of the groove is 7.4 mm and the width is 1.7 mm; the length of the microstrip transmission line is 25 mm and the width is 1.2 mm.

[0017] In some embodiments, the insulating dielectric substrate is an F4BM220 dielectric plate with a length of 90 mm and a width of 70 mm, a dielectric constant of 2.2, a loss tangent of 0.0009, and a thickness of 2 mm.

[0018] Beneficial effects of the present invention:

[0019] The microstrip antenna device of the present invention has a low profile height and a compact size, and simultaneously maintains far-field radiation with wide azimuth coverage in two frequency bands, and has excellent wide coverage, high resolution, and high gain performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, as part of this disclosure, are intended to provide a further understanding of the disclosure. The exemplary embodiments of the disclosure and their descriptions are intended to explain the disclosure and do not constitute undue limitations thereon. Obviously, the drawings described below are merely examples, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0021] In the attached figure:

[0022] Figure 1 This is a schematic diagram of the dual-band microstrip antenna structure proposed by the present invention;

[0023] Figure 2 This is a schematic diagram of the first metal patch structure proposed by the present invention;

[0024] Figure 3 This is a reflection coefficient curve of the dual-band microstrip antenna proposed in the present invention;

[0025] Figure 4 This is the far-field radiation pattern of the e-plane of the dual-band microstrip antenna proposed in the present invention at 5.13 GHz;

[0026] Figure 5 This is the far-field radiation pattern of the h-plane of the dual-band microstrip antenna proposed in the present invention at 5.13 GHz;

[0027] Figure 6The far-field radiation pattern of the dual-band microstrip antenna proposed in the present invention at 5.48 GHz and in the e-plane;

[0028] Figure 7 This is the far-field radiation pattern of the dual-band microstrip antenna proposed in the present invention at 5.48 GHz and in the h-plane.

[0029] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but rather to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. Implementation Method

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0031] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the present invention.

[0032] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; and direct or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0033] like Figure 1 As shown, a dual-band microstrip antenna with a wide fan beam and a rectangular beam comprises a first metal patch 1, an insulating dielectric substrate 2, a second metal patch 3, a microstrip transmission line 4, and a metal via 5. The first metal patch 1 and the microstrip transmission line 4 are made of conductive material and are located on the first surface of the insulating dielectric substrate 2. One side of the microstrip transmission line 4 is connected to the first metal patch 1, and the other side serves as the antenna feed terminal for signal input. A metal via 5 is provided on the first metal patch 1 to short-circuit the first metal patch 1 and the ground plane. The second metal patch 3 covers the second surface of the insulating dielectric substrate 2. Like conventional microstrip antennas, the proposed antenna can be conveniently excited via an SMA feed connector soldered to the microstrip transmission line 4.

[0034] like Figure 2 As shown, the first metal patch 1 includes a radiation patch 1-1, a metal strip 1-2 and a short microstrip line 1-3; the radiation patch 1-1 is a rectangular patch, and a symmetrically arranged groove is cut in the middle of the upper and lower long edges of the radiation patch 1-1; a metal strip 1-2 parallel to the long edge is provided on the outer side of the upper and lower long sides of the radiation patch 1-1; the short microstrip line 1-3 connects the metal strip 1-2 and the radiation patch 1-1.

[0035] A further solution is as follows: two metal strips 1-2 are provided on the outer sides of the upper and lower long sides of the radiation patch 1-1, and there is a gap between the two metal strips 1-2 on the same side; each metal strip 1-2 is connected to the radiation patch 1-1 through two short microstrip lines 1-3 arranged at intervals and in parallel.

[0036] A further solution: the four metal strips 1 - 2 are symmetrical about the center of the radiation patch 1 - 1 .

[0037] A further solution is as follows: the outer wide side of the metal strip 1-2 is flush with the outer wide side of the radiation patch 1-1, and the inner wide side of the metal strip 1-2 is located between the center line of the long side of the radiation patch 1-1 and the wide side of the groove; one of the short microstrip lines 1-3 is connected to the long side of the metal strip 1-2 along the wide side of the groove, and the other short microstrip line 1-3 is connected to the long side of the metal strip 1-2 near the wide side of the radiation patch 1-1.

[0038] Further solution: In order to generate resonance at the desired frequency and improve impedance matching, a metal through hole 5 is loaded at the outermost corner of each of the four metal strips 1-2 to short-circuit the first metal patch 1 and the ground plate.

[0039] A further solution: To achieve a rectangular radiation beam, two slots 1-4 are etched into radiating patch 1-1, symmetrically about the centerline of its long side. This alters the current distribution and radiation pattern. A metal via 5 is added to each side of each slot 1-4, near the center of the radiating patch, short-circuiting the first metal patch 1 and the ground plane.

[0040] Preferred solution: The first metal patch 1 is a rectangular patch with a length of 60 mm and a width of 44 mm.

[0041] Preferred solution: The groove width of the radiation patch 1-1 is 7.4 mm and the depth is 1.7 mm.

[0042] Preferred solution: The radius of the metal through hole 5 is 0.5 mm, which is conducive to improving the impedance matching of the antenna.

[0043] Preferred solution: The length of the slots 1-4 is 22 mm and the width is 0.5 mm, which is used to change the current distribution and is conducive to improving the far-field radiation direction of the antenna.

[0044] Preferred solution: The length of the microstrip transmission line 4 is 25 mm and the width is 1.2 mm, and it is used to transmit the electrical signal input by the feed connector.

[0045] Preferred solution: The insulating dielectric substrate 2 is an F4BM220 dielectric plate with a length of 90 mm and a width of 70 mm, a dielectric constant of 2.2, a loss tangent of 0.0009, and a thickness of 2 mm.

[0046] As can be seen from the above, the present invention provides a dual-band microstrip antenna with a wide fan beam and a rectangular beam, comprising a first metal patch, an insulating dielectric substrate, a second metal patch, a microstrip transmission line, and a metal via. Specifically, the structure of this microstrip antenna is as follows: a rectangular radiating patch with wide side slots, four parallel metal strips, and eight short microstrip lines connecting the metal strips and the rectangular radiating patch. A metal via is installed on each of the four parallel metal strips to short-circuit the metal patch and the ground plane. Two symmetrical slots are etched in the rectangular radiating patch, and a metal via is installed on each side of each slot near the center of the rectangular radiating patch to electrically short-circuit the ground plane. Like conventional microstrip antennas, the proposed antenna can be conveniently excited via a 50-ohm SMA connector soldered to the microstrip feed line. The microstrip antenna of the present invention has a low profile, a small size, and a fan beam and a rectangular radiating beam with a wide HPBW.

[0047] Figure 3 This is a reflection coefficient curve diagram of the dual-frequency microstrip antenna device proposed by the present invention. In the figure, the horizontal axis represents the frequency variable in GHz; the vertical axis represents the amplitude variable. Figure 2 It can be seen that the antenna of the present invention achieves good impedance matching (|S11|<-25 dB) at both 5.13 GHz and 5.48 GHz.

[0048] Figure 4 、 Figure 5 The far-field radiation patterns of the dual-band microstrip antenna device proposed in the present invention are shown in the e-plane and h-plane, respectively. It can be seen from the figure that at 5.13 GHz, the e-plane HPBW beamwidth of the radiation pattern is 140°, the maximum gain is 8.34 dB, and the far-field radiation has a wide azimuth coverage.

[0049] Figure 6 、 Figure 7 The far-field radiation patterns of the dual-band microstrip antenna device proposed in the present invention are shown in the e-plane and h-plane, respectively. As can be seen from the figure, at 5.48 GHz, the e-plane HPBW beamwidth of the radiation pattern is 100°, the h-plane HPBW beamwidth is 90°, the maximum gain is 5.8 dB, and the far-field radiation has a wide azimuth coverage.

[0050] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0051] Furthermore, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, combinations of features from different embodiments are also intended to fall within the scope of protection of the present invention and form different embodiments. For example, in the above embodiments, those skilled in the art will be able to use them in combination based on the known technical solutions and the technical problems to be solved by this application.

[0052] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with this patent can make slight changes or modifications to equivalent embodiments using the above-mentioned technical contents without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the solution of the present invention.

Claims

1. A dual-band microstrip antenna with a wide fan beam and a rectangular beam, characterized by: It includes a first metal patch (1), an insulating dielectric substrate (2), a second metal patch (3), a microstrip transmission line (4), and a metal through hole (5); The first metal patch (1) and the microstrip transmission line (4) are both located on the first surface of the insulating dielectric substrate (2); One side of the microstrip transmission line (4) is connected to the first metal patch (1), and the other side serves as the feeding end of the antenna for signal input; A metal through hole (5) is loaded on the first metal patch (1) to short-circuit the first metal patch (1) and the ground plate; The second metal patch (3) covers the second surface of the insulating dielectric substrate (2); The first metal patch (1) comprises a radiation patch (1-1), a metal strip (1-2) and a short microstrip line (1-3); The radiation patch (1-1) is a rectangular patch, and a symmetrically arranged groove is cut in the middle of the upper and lower elongated edges of the radiation patch (1-1); Two metal strips (1-2) parallel to the long sides are respectively provided on the outside of the upper and lower long sides of the radiation patch (1-1), and a gap is provided between the two metal strips (1-2) on the same side; Each metal strip (1-2) is connected to the radiation patch (1-1) through two short microstrip lines (1-3) that are spaced apart and arranged in parallel.

2. A dual-band microstrip antenna with a wide fan beam and a rectangular beam according to claim 1, characterized in that: The four metal strips (1-2) are symmetrical about the center of the radiation patch (1-1).

3. The dual-band microstrip antenna with a wide fan beam and a rectangular beam according to claim 1, characterized in that: The outer wide side of the metal strip (1-2) is flush with the outer wide side of the radiation patch (1-1), and the inner wide side of the metal strip (1-2) is located between the center line of the long side of the radiation patch (1-1) and the wide side of the groove; One of the short microstrip lines (1-3) is connected to the long side of the metal strip (1-2) along the wide side of the groove, and the other short microstrip line (1-3) is connected to the long side of the metal strip (1-2) near the wide side of the radiation patch (1-1).

4. The dual-band microstrip antenna with a wide fan beam and a rectangular beam according to claim 1, characterized in that: In order to generate resonance at a desired frequency point and improve impedance matching, a metal through hole (5) is loaded at each of the outermost corners of the four metal strips (1-2) to short-circuit the first metal patch (1) and the ground plate.

5. The dual-band microstrip antenna with a wide fan beam and a rectangular beam according to claim 1, characterized in that: In order to realize a rectangular radiation beam, two slits (1-4) symmetrical about the center line of the long side of the radiation patch (1-1) are etched on the radiation patch (1-1).

6. The dual-band microstrip antenna with a wide fan beam and a rectangular beam according to claim 5, characterized in that: A metal through hole (5) is loaded on one side of each gap (1-4) close to the center of the radiation patch, so as to short-circuit the first metal patch (1) and the ground plate.

7. The dual-band microstrip antenna with a wide fan beam and a rectangular beam according to claim 1, characterized in that: The length of the first metal patch (1) is 60 mm and the width is 44 mm; the length of the groove is 7.4 mm and the width is 1.7 mm; the length of the microstrip transmission line (4) is 25 mm and the width is 1.2 mm.

8. The dual-band microstrip antenna with a wide fan beam and a rectangular beam according to claim 1, characterized in that: The insulating dielectric substrate (2) is an F4BM220 dielectric plate with a length of 90 mm and a width of 70 mm, a dielectric constant of 2.2, a loss tangent of 0.0009, and a thickness of 2 mm.

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