Wide-beam high-gain microstrip antenna

Abstract

The invention provides a wide-beam high-gain microstrip antenna, and belongs to the technical field of wireless communication and antennas. Comprising a metal patch, a dielectric substrate and a metal parasitic patch, the metal patches are divided into a front part and a back part which are alternately placed on the front surface and the back surface of the dielectric substrate, namely, the metal patches with different widths are alternately arranged on the front surface and the back surface of the dielectric substrate, and the current distribution and impedance characteristics are adjusted through the gap structure to realize broadband matching and high-gain radiation; the metal parasitic patches are placed on the front face of the dielectric substrate and serve as a reflector and a director respectively, and a wide-beam directional radiation pattern is formed. The microstrip antenna provided by the invention can realize the characteristics of wide beam and high gain at the same time, can cover 2.12-2.78 GHz through the collaborative design of gap coupling and parasitic units, and realizes the impedance bandwidth exceeding 26%; the antenna can be expanded to any frequency band; a single-layer board integrated structure is adopted, excellent radiation performance is kept, and meanwhile, the antenna has the remarkable advantages of being low in profile, high in integration level and low in manufacturing cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of wireless communication and antenna technology, and relates to a wide-beam high-gain microstrip antenna. BACKGROUND

[0002] Wireless communication technology is continuously evolving towards the 5G-Advanced and 6G vision, and the system requirements for data transmission rate, connection reliability and coverage uniformity are constantly increasing. This directly promotes the development of antenna design towards higher performance, especially in complex mobile scenarios, requiring the antenna to maintain stable and efficient energy radiation within a wide spatial angle, i.e., simultaneously possessing wide-beam coverage and high-gain characteristics. However, according to the basic principles of antenna theory, there is an inherent trade-off relationship between beam width and gain. Traditional antenna designs often face inherent trade-offs between gain and beam width, making it difficult to simultaneously improve both. Expanding the beam width will inevitably lead to a decrease in gain, while increasing the gain will result in a narrowing of the beam. This contradiction has become a key bottleneck restricting the further improvement of modern communication system performance, and needs to be broken through.

[0003] Microstrip antennas have a wide range of applications in modern wireless communication due to their compact structure, low profile, ease of integration with circuits, and mass production advantages. They are commonly used in smartphones, wireless routers, Internet of Things terminals, and various portable devices, and are one of the key components for wireless signal transmission and reception. With the continuous evolution of the fifth generation (5G) and future communication technologies, communication devices have higher requirements for antenna performance. For example, in indoor distributed antenna, vehicle-mounted communication module, and metal frame notebook computer scenarios, it is necessary to achieve stable large-angle signal coverage within a limited cross-section; in unmanned aerial vehicle image transmission, high-definition video streaming, and other high-rate services, it is necessary to maintain high gain within a wide beam range to ensure link reliability and transmission efficiency.

[0004] However, traditional microstrip antennas generally face the inherent problem of a sharp decline in gain when expanding the beam width. Existing improvement techniques mainly include the following approaches: first, using a multi-layer stacked structure to excite multi-mode resonance by adding parasitic radiation patches or coupled feed layers, but this approach significantly increases the antenna profile thickness and the number of dielectric substrates; second, designing a complex feed network, such as a phased array structure or a series feed network with integrated dividers and phase shifters, which can achieve beam control but introduces additional transmission loss and impedance matching difficulties; third, combining different types of antennas to form a hybrid structure, such as combining microstrip patches with dipoles or slot antennas, but this design often faces challenges such as complex processing technology and mismatched radiation patterns. These improvement schemes can improve performance in certain indicators, but generally at the cost of profile thickness, structural simplicity, and manufacturing cost, making it difficult to meet the comprehensive requirements of modern communication devices for thinness, high integration, and low-cost mass production.

[0005] Therefore, how to realize the coordinated promotion of wide beam and high gain under the premise of structural simplification has become an important direction of current microstrip antenna research. A low-profile microstrip antenna design scheme based on a single-layer dielectric plate is proposed, which effectively realizes the unification of wide beam characteristics and high gain performance on the basis of maintaining simple structure and convenient processing, provides a solution for high-performance antennas in new generation communication equipment, and has great market application potential. SUMMARY

[0006] The present application proposes an innovative planar structure antenna scheme to solve the technical contradictions in realizing wideband, high gain and wide beam coverage of existing microstrip antennas. The antenna adopts a unique radiator configuration, in which wide-size radiation patches and narrow-size microstrip connecting lines are alternately arranged according to a specific rule and accurately distributed on both sides of the dielectric substrate. Among them, the adjacent radiation units are connected through the structure design of cross-layer interconnection, realizing a stable phase difference of approximately 180° between adjacent radiation units, thereby ensuring that the current distribution on the entire radiator maintains a strict in-phase characteristic, laying a structural foundation for obtaining high gain radiation characteristics.

[0007] To break through the bandwidth limitation of traditional design, the present application introduces a new gap structure in the key coupling area of adjacent radiation units. The controllable capacitive coupling effect generated by the gap can effectively compensate the inductive component of the antenna system after optimization design, realizing significant impedance bandwidth expansion without introducing additional matching network. In terms of radiation characteristic regulation, the present application sets an asymmetrically distributed parasitic patch system on both sides of the radiator. Among them, the parasitic unit on one side adopts an innovative U-shaped topology structure, which significantly improves the forward radiation efficiency through effective regulation of near-field energy; the parasitic unit on the other side adopts a tapered size arrangement, which establishes an optimized electromagnetic wavefront phase distribution, realizes effective expansion of beam width while maintaining radiation directionality. In addition, the perturbation slot structure optimized by electromagnetic simulation is introduced on the surface of the main radiation unit. These specially configured slots improve the radiation phase consistency of the antenna unit by reconstructing the surface current path, further improving the overall radiation efficiency.

[0008] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0009] A wide-beam high-gain microstrip antenna, the wide-beam high-gain microstrip antenna is arranged alternately on the front and back surfaces of a dielectric substrate with wide and narrow metal patches, and the current distribution and impedance characteristics are adjusted through the gap structure arranged therebetween to realize wideband matching and high-gain radiation; meanwhile, a plurality of parasitic patches are arranged on the front surface of the dielectric substrate, which are respectively used as reflectors and directors to form a wide-beam directional radiation pattern. The structure has the characteristics of wide-beam coverage, high gain and directional radiation, and is suitable for modern wireless communication systems. The wide-beam high-gain microstrip antenna comprises: a metal patch 1, a dielectric substrate 2, a metal parasitic patch 3, and a metal microstrip connecting line 4, the metal patch 1 is divided into front and back parts and is arranged alternately on the front and back surfaces of the dielectric substrate 2, and the metal parasitic patch 3 is arranged on the front surface of the dielectric substrate. Specifically,

[0010] The metal patch 1 is a wide-size radiation patch 1-1, which is arranged alternately on the surface of the dielectric substrate 2 through a narrow-size metal microstrip connecting line 4 to form a collinear array structure on the surface of the dielectric substrate 2. The length of the wide-size radiation patch is designed to be 0.4~0.6 , wherein represents the dielectric waveguide wavelength; the metal patch 1 is arranged alternately on the dielectric substrate 2 to realize phase inversion between adjacent wide-size radiation patches 1-1, to ensure that the current distribution on all wide-size radiation patches 1-1 has high consistency, to form a same-phase radiation array to realize high-gain characteristics. There is a gap structure 1-2 between adjacent wide-size radiation patches 1-1, which is equivalent to introducing a capacitive load, and the impedance matching can be optimized effectively by adjusting the width of the gap structure, thereby realizing wideband characteristics.

[0011] The front surface of the dielectric substrate 2 is arranged with the metal patch 1 arranged alternately, which directly acts as a signal input end at the feeding point to form the simplest balanced radiation structure. Among them, the left edge of the leftmost metal patch 1 is flush with the left edge of the dielectric substrate 2, and the right edge of the rightmost metal patch 1 has a gap structure 1-2 with the right edge of the dielectric substrate 2, and the flush leftmost metal patch 1 is defined as the initial metal patch 1. The wide-beam high-gain microstrip antenna adopts a side feeding mode to directly excite, and two differential signal ends of the feeding system are directly connected to the initial metal patch 1 located on the front and back surfaces of the dielectric substrate 2 to form the simplest feeding structure. This direct side feeding mode does not require additional metalized vias or complex feeding networks, effectively simplifying the antenna structure, reducing the manufacturing cost, and avoiding the insertion loss introduced by the complex feeding network. The metal parasitic patch 3 includes a reflector 3-1 and a director 3-2, which are arranged on both sides of the center line of the wide-size radiation patch 1-1 along the length direction. Specifically, a plurality of groups of reflectors 3-1 are arranged at intervals on one side of the wide-size radiation patch 1-1, and a plurality of groups of directors 3-2 are arranged at intervals on the other side. The reflector 3-1 adopts a U-shaped structure design, the width of which can be adjusted, and the length is greater than wherein represents the free space operating wavelength, used to suppress backward radiation and reduce backward lobe level; the director 3-2 is composed of multiple patches in length progression, wherein the longest patch is close to the wide-size radiation patch 1-1, and the length of the longest patch is less than , used to enhance forward gain and improve beam directivity. Meanwhile, the center of the reflector and the director corresponds to the center of the wide-size metal radiation patch.

[0012] Further, the surface of the wide-size radiation patch 1-1 at the center of the front of the dielectric substrate 2 is excavated with a slot 1-3 according to current distribution characteristics. The slot 1-3 can guide the surface current to flow along a preset path, reduce the inconsistency of current loops, and further improve the radiation efficiency and overall gain of the antenna unit.

[0013] Further, the wide-size radiation patch 1-1 of the metal patch 1 and the narrow-size metal microstrip connection line 4 are connected to each other, ensuring that the length of each wide-size radiation patch is 0.4~0.6 , so that all the radiation unit currents are in phase, realizing high-gain radiation characteristics.

[0014] Further, the distance of the gap structure 1-2 between adjacent wide-size radiation patches 1-1 in the metal patch 1 is adjustable, the size of the equivalent capacitive load is controlled by optimizing the gap size, the impedance matching characteristics are adjusted, and wideband operation is realized. Preferably, the width of the gap structure 1-2 is in the range of 0.5mm-3mm.

[0015] Further, in the parasitic patch 3, the reflector adopts a U-shaped structure, and the director adopts a multiple-patch configuration in length progression. By optimizing the size and spacing of the reflector and the director, the front-to-back ratio and beam width of the antenna can be further improved.

[0016] Further, the dielectric substrate 2 adopts a low dielectric constant, and the dielectric constant is not greater than 10.

[0017] Further, the feeding mode is not limited to the side feeding mode, and different modes such as CPW and microstrip line feeding can be used to adapt to various application scenarios.

[0018] When CPW feeding is used, a CPW transmission line is made on the front of the dielectric substrate, the center signal guide band is connected to the back initial driving unit through a metalized via, and the two side ground guide bands are connected to the corresponding unit on the front through another group of metalized vias; when microstrip line feeding is used, a microstrip transmission line is made on the front of the dielectric substrate, the signal line is directly connected to the front initial driving unit, and the back driving unit and system ground are connected through a metalized via.

[0019] Further, the number of wide-size radiation units in the metal patch 1 is not limited to a specific number, and can be increased or decreased according to gain requirements, and the unit size can also be adjusted according to frequency requirements.

[0020] Further, the shape of the metal parasitic patch 3 is not limited to U-shaped and rectangular, and can be triangular, circular or other polygonal structures according to actual requirements, so as to realize specific directional pattern characteristics.

[0021] Further, the slot on the surface of the metal patch 1 is not limited to a specific shape, and can be U-shaped, L-shaped, ring-shaped or other complex shapes, so as to optimize the antenna performance by changing the current path.

[0022] The innovation points of the present application are analyzed as follows:

[0023] (1) A microstrip antenna design scheme is provided, which simultaneously realizes wide frequency band, high gain and wide beam in a single planar structure.

[0024] (2) By the coordinated design of wide and narrow patch alternation layout, gap coupling and surface slot, a high-consistency in-phase current distribution is constructed, and high gain and wide frequency band characteristics are simultaneously realized.

[0025] (3) The parasitic structure combination of U-shaped reflector and progressive director is adopted, which effectively expands the beam width while maintaining the directional radiation characteristics.

[0026] The actual measurement results show that the antenna of the present application exhibits excellent comprehensive performance in the frequency band of 2.12-2.78GHz: the impedance matching bandwidth reaches 26.94%, the peak gain is more than 8.5dBi, and the 3dBi beam width in the main radiation direction is more than 160°. This performance breakthrough is due to the coordinated design between the structure units, in which the cross-layer phase control structure, capacitive gap coupling, U-shaped parasitic unit, tapered parasitic array and perturbation slot are organically combined, which together realize the significant improvement of the antenna performance. The present application effectively balances the performance constraints between wide frequency band, high gain and wide beam through the coordinated design in a single planar structure, and provides a practical technical path for modern communication equipment with strict requirements on the comprehensive performance of the antenna.

[0027] Compared with the prior art, the present application has the following beneficial effects:

[0028] (1) The microstrip antenna of the present application can simultaneously realize wide beam and high gain characteristics, and the highest gain of the antenna beam can reach ~8.7dBi, and the beam width of the antenna with a gain of more than 3dBi in the bandwidth can reach nearly 165°.

[0029] (2) Through the collaborative design of gap coupling and parasitic units, this invention can cover 2.12GHz-2.78GHz, achieving an impedance bandwidth of over 26%; however, it is not limited to this frequency band and can be extended to any frequency band. (3) This invention adopts a single-layer integrated structure, which maintains excellent radiation performance while also having the significant advantages of low profile, high integration and low manufacturing cost. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the wide-beam high-gain microstrip antenna proposed in this invention;

[0031] Figure 2 This is a magnified view of a portion of metal patch 1;

[0032] Figure 3 This is a cross-sectional schematic diagram of the overall structure of the wide-beam high-gain microstrip antenna proposed in this invention;

[0033] Figure 4 This is a schematic diagram of the front and back structures of the wide-beam high-gain microstrip antenna proposed in this invention; Figure 4 (a) in the figure represents the front view, where L = 160 mm and W = 60 mm; Figure 4 (b) in the diagram represents the reverse side;

[0034] Figure 5 These are the reflection coefficient curves and gain diagrams simulated in this invention;

[0035] Figure 6 This is the simulation pattern of the xoz plane at 2.45 GHz according to the present invention;

[0036] In the figure: 1. Metal patch; 2. Dielectric substrate; 3. Metal parasitic patch; 4. Metal microstrip interconnect;

[0037] 1-1 Wide-size radiating patch; 1-2 Gap structure; 1-3 Slot;

[0038] 3-1 Reflector; 3-2 Director. Detailed Implementation

[0039] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings and technical solutions.

[0040] refer to Figure 1 A schematic diagram of the overall structure of a wide-beam, high-gain microstrip antenna. The antenna consists of four parts: a metal patch 1, a dielectric substrate 2, a metal parasitic patch 3, and a metal microstrip connecting line 4.

[0041] refer to Figure 2A partially enlarged view of the metal patch 1 shows that it consists of a wide-sized radiating patch 1-1, a gap structure 1-2, and a slot 1-3. The wide-sized radiating patches 1-1 are connected by narrow-sized metal microstrip connecting lines 4. The length of the wide-sized radiating patch 1-1 is equal to the wavelength of the dielectric waveguide. Half of the array, specifically measuring 29.6 mm × 16 mm; the narrow-size metal microstrip connecting line 4 is 32 mm long and 1.3 mm wide, slightly larger than the spacing between adjacent wide patches to form an impedance-adjusting gap structure 1-2. The surface of the wide-size radiating patch located at the center of the array has symmetrical triangular slots 1-3, forming a bow-shaped radiating structure.

[0042] refer to Figure 3 Cross-sectional view of a wide-beam, high-gain microstrip antenna. The rectangular low-dielectric-constant dielectric substrate 2 is made of FR4 material ( , The dielectric substrate 2 has a thickness of 0.8 mm, a length of 160 mm, and a width of 60 mm. Metal patches 1 are arranged in two groups on the upper and lower surfaces of the dielectric substrate 2, forming a balanced radiation structure. Metal parasitic patches 3 are arranged on the upper surface of the dielectric substrate 2. Reflectors 3-1 have a U-shaped structure with a horizontal section of 50 mm × 7 mm and a vertical section of 9 mm × 3 mm, spaced 8 mm from metal patches 1. Directors 3-2 use an array layout with decreasing lengths; the longer unit has a size of 30 mm × 3 mm, and the shorter unit has a size of 25 mm × 3 mm, with the longer unit spaced 6 mm from metal patches 1. All metal parasitic patches are aligned with the center of the corresponding wide-size radiating patch 1-1, and the reflector length is greater than... The director length is less than ( The operating bandwidth is 2.4 GHz, and the operating wavelength in free space is 2.4 GHz.

[0043] refer to Figure 4 (a) is a top view of dielectric substrate 2, showing the structural layout of the upper surface of dielectric substrate 2, including a reflector and director array composed of metal patch 1 and metal parasitic patch 3 and metal microstrip connection line 4.

[0044] refer to Figure 4 (b) is a bottom view of dielectric substrate 2, showing the structural layout of the lower surface of dielectric substrate 2. It adopts a metal patch 1 arrangement that is complementary to the upper surface. The metal patches on the upper and lower surfaces are directly connected at the feed point to form the simplest balanced feed structure.

[0045] refer to Figure 5The simulation results of the reflection coefficient and gain of the wide-beam high-gain microstrip antenna show that the antenna's impedance bandwidth is 2.12 GHz to 2.78 GHz, and the maximum gain achievable within the operating bandwidth is 8.74 dBi. The gain is greater than 5.69 dBi within the impedance bandwidth.

[0046] refer to Figure 6 The figure shows the normalized radiation pattern of the wide-beam, high-gain microstrip antenna in the E-plane at 2.45 GHz. As can be seen from the figure, the beamwidth of the antenna's E-plane radiation pattern at the operating frequency can reach approximately 165°.

[0047] The above-described embodiments are merely illustrative of the implementation methods of the present invention, but should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A wide-beam high-gain microstrip antenna, characterized by, The wide-beam high-gain microstrip antenna comprises a metal patch (1), a dielectric substrate (2), a metal parasitic patch (3) and a metal microstrip connecting line (4); The metal patch (1) is alternately arranged on the front and back surfaces of the dielectric substrate (2), that is, the wide and narrow metal patches (1) are alternately arranged on the front and back surfaces of the dielectric substrate (2), and the gap structure arranged therebetween is used to adjust the current distribution and impedance characteristics, so as to realize wideband matching and high-gain radiation. The metal parasitic patch (3) is arranged on the front surface of the dielectric substrate (2) and serves as a reflector (3-1) and a director (3-2) respectively, so as to form a wide-beam directional radiation pattern. The metal patch (1) is alternately arranged on the surface of the dielectric substrate (2) through the narrow-size metal microstrip connecting line (4).

2. A wide-beam high-gain microstrip antenna according to claim 1, characterized in that The metal patch (1) is a wide-size radiation patch (1-1) in a collinear array structure on the surface of the dielectric substrate (2); the length of the wide-size radiation patch is designed to be 0.4~0.6 wherein represents the dielectric waveguide wavelength; The dielectric substrate (2) is alternately arranged on the front and back surfaces to realize phase inversion between adjacent wide-size radiation patches (1-1), so as to form a same-phase radiation array to realize high-gain characteristics. The gap structure (1-2) between the adjacent wide-size radiation patches (1-1) is used to optimize impedance matching by adjusting the width of the gap structure, so as to realize wideband characteristics; the size of the equivalent capacitive load is controlled by optimizing the gap size, so as to adjust the impedance matching characteristics and realize wideband operation. The front surface of the wide-size radiation patch (1-1) at the center of the dielectric substrate (2) is excavated according to the current distribution characteristics.

3. A wide-beam high-gain microstrip antenna according to claim 2, wherein, The width of the gap structure (1-2) between the adjacent wide-size radiation patches (1-1) ranges from 0.5 mm to 3 mm.

4. A wide-beam high-gain microstrip antenna according to claim 1, wherein, The dielectric substrate (2) is arranged with the metal patch (1) alternately arranged on the front and back surfaces, which directly serves as a signal input end at the feeding point to form a balanced radiation structure; wherein the left edge of the leftmost metal patch (1) is flush with the left edge of the dielectric substrate (2), and the right edge of the rightmost metal patch (1) has a gap structure (1-2) with the right edge of the dielectric substrate (2), and the leftmost metal patch (1) is defined as an initial metal patch (1). The wide-beam high-gain microstrip antenna adopts a side feeding mode to directly excite two differential signal ends of the feeding system, which are directly connected to the initial metal patches (1) on the front and back surfaces of the dielectric substrate (2) to form a simplest feeding structure.

5. A wide-beam high-gain microstrip antenna according to claim 1, wherein, The metal parasitic patch (3) comprises a reflector (3-1) and a director (3-2), which are arranged on both sides of the center line of the wide-size radiation patch (1-1) along the length direction, that is, a plurality of groups of reflectors (3-1) are arranged on one side of the wide-size radiation patch (1-1) with a certain interval, and a plurality of groups of directors (3-2) are arranged on the other side with a certain interval.

6. A wide-beam high-gain microstrip antenna according to claim 5, wherein, The reflector (3-1) adopts a U-shaped structure design, the width of which is adjustable, and the length is greater than , wherein represents the free space operating wavelength; the director (3-2) is composed of multiple patches along the length, wherein the longest patch is close to the wide-size radiation patch (1-1), and the length is less than , for enhancing the forward gain and improving the beam directivity; the centers of the reflector (3-1) and the director (3-2) correspond to the center of the wide-size metal radiation patch (1-1); by optimizing the size and spacing of the reflector (3-1) and the director (3-2), the front-to-back ratio and beam width of the antenna are improved.

7. A wide-beam high-gain microstrip antenna according to claim 1, wherein, The wide-size radiation patch (1-1) of the metal patch (1) and the narrow-size metal microstrip connecting line (4) are connected to each other, the length of each wide-size radiation patch (1-1) is 0.4~0.6 , and high-gain radiation characteristics are achieved.

8. A wide-beam high-gain microstrip antenna according to claim 1, wherein, The dielectric substrate (2) adopts a low dielectric constant.

9. A wide-beam high-gain microstrip antenna according to claim 1, characterized in that The feeding mode is not limited to the side feeding mode, and different modes such as CPW and microstrip line feeding can be adopted to adapt to various application scenarios. When CPW feed is used, CPW transmission line is made on the front surface of the dielectric substrate (2), the center signal conductor is connected to the initial driving unit on the back surface through metallized via, and the two side ground conductors are connected to the corresponding unit on the front surface through another set of metallized via; when microstrip line feed is used, microstrip transmission line is made on the front surface of the dielectric substrate (2), the signal line is directly connected to the initial driving unit on the front surface, and is connected to the driving unit on the back surface and the system ground through metallized via.

10. A wide-beam high-gain microstrip antenna according to claim 1, wherein, In the wide-beam high-gain microstrip antenna: The number of wide-size radiation units in the metal patch (1) is not limited to a specific number, and can be increased or decreased according to the gain requirement, and the size can be adjusted according to the frequency requirement; The shape of the metal parasitic patch (3) is not limited to U-shaped and rectangular, and can be triangular, circular or other polygonal structure according to actual requirements to realize specific directional pattern characteristics; The slot on the surface of the metal patch (1) is not limited to a specific shape, and can be U-shaped, L-shaped, ring-shaped or other complex shapes to optimize the performance of the antenna by changing the current path.

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