A low profile miniaturized dual-band antenna based on LC resonance loading

Abstract

The application provides a low-profile miniaturized dual-band antenna based on LC resonance loading, relates to the technical field of microstrip antenna structure design, and comprises a metal floor, a dielectric plate, a radiation structure, an LC resonance structure and a feeding structure, the dielectric plate is fixedly arranged above the metal floor; the radiation structure is arranged above the dielectric plate, the radiation structure is composed of coaxial metal circular patches, a plurality of through holes are arranged on the radiation structure; the LC resonance structure is arranged in the through hole of the radiation structure; the feeding structure is arranged on the center line of the radiation structure, and the top end of the feeding structure penetrates through the dielectric plate and is connected with the radiation structure. The low-frequency antenna miniaturization and low-profile problem of the traditional low-frequency antenna are overcome, the size is significantly reduced, and the dual-band working capacity and good radiation performance are maintained.

Description

Technical Field

[0001] This invention relates to the field of microstrip antenna structure design technology, and more specifically, to a low-profile miniaturized dual-band antenna based on LC resonant loading. Background Technology

[0002] With the rapid development of modern communication technology, communication systems place increasingly higher demands on antennas. They not only need to cover a wider range of frequency bands, but also require higher spectral efficiency and stronger anti-interference capabilities. Meanwhile, antenna miniaturization has become a key technology to meet the needs of modern portable and space-constrained platforms. Multi-band antennas, as antennas capable of operating simultaneously on multiple frequency bands, perfectly meet this requirement.

[0003] Currently, there are two main ways to implement multi-band antennas: slotting on the patch and stacking multiple dielectric layers. To achieve vertical polarization, the antenna profile will be too high, making it difficult to install. At the same time, if resonance is to be achieved in the low-frequency band, the size of the antenna will be increased, increasing the installation space.

[0004] Current multi-band antenna design methods often employ multi-layer dielectric stacking and slotting techniques to simultaneously achieve multi-band and vertical polarization. While multi-layer dielectric stacking allows for multiple resonant points, it increases the number of antenna layers, inevitably increasing the antenna's profile height. Slotting the floor with different lengths or shapes allows the antenna, or its combination with radiating patches, to resonate at multiple specific frequencies, enabling multi-band operation. However, slotting the floor prevents installation on metal floors. Furthermore, achieving resonance at low frequencies typically increases the antenna's lateral dimensions and profile height, increasing its overall size and hindering installation in space-constrained environments.

[0005] Therefore, there is an urgent need for a low-profile, miniaturized dual-band antenna based on LC resonant loading to solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to provide a low-profile, miniaturized dual-band antenna based on LC resonant loading to improve the aforementioned problems. To achieve this objective, the technical solution adopted by this invention is as follows: In a first aspect, this application provides a low-profile miniaturized dual-band antenna based on LC resonant loading, comprising: a metal ground plane, a dielectric substrate, a radiating structure, an LC resonant structure, and a feeding structure. The dielectric substrate is fixedly disposed directly above the metal ground plane. The radiating structure is disposed directly above the dielectric substrate and is composed of multiple coaxial circular metal patches, with multiple through holes provided on the radiating structure. The LC resonant structure is disposed within the through holes of the radiating structure. The feeding structure is disposed on the centerline of the radiating structure, and the top end of the feeding structure passes through the dielectric substrate and connects to the radiating structure.

[0007] Optionally, the dielectric constant of the dielectric substrate is 2.2 and the loss tangent is 0.003.

[0008] Optionally, the radiating structure includes a central circular radiating patch, a first annular patch, a second annular patch, and a third annular patch. The central circular radiating patch, the first annular patch, the second annular patch, and the third annular patch are all attached to the upper surface of the dielectric substrate. The central circular radiating patch is connected to the feeding structure. The third annular patch is sleeved outside the central circular radiating patch. The second annular patch is disposed between the central circular radiating patch and the third annular patch. The first annular patch is disposed between the central circular radiating patch and the second annular patch.

[0009] Optionally, the central circular radiating patch, the first annular patch, the second annular patch, and the third annular patch have the same thickness, and their central axes are located at the same position.

[0010] Optionally, each of the central circular radiating patch, the first annular patch, the second annular patch, and the third annular patch has annular gaps between each other.

[0011] Optionally, both the first and third annular patches are provided with at least six through holes, and each through hole is provided with an LC resonant structure, which is fixedly connected to the inner wall of its corresponding through hole.

[0012] Optionally, the LC resonant structure includes a central circular pad, a short-circuit post inductor, and a capacitor patch. The central circular pad is fixedly disposed on the dielectric substrate. The central axis of the central circular pad and the central axis of the through hole are on the same straight line. An annular gap is provided between the central circular pad and the through hole. The central circular pad and the through hole are connected by the capacitor patch. The two ends of the short-circuit post inductor pass through the dielectric substrate and are respectively connected to the central circular pad and the metal ground plate.

[0013] Optionally, the short-circuit post inductor is a metal post.

[0014] Optionally, the power supply structure includes a stepped power supply column and a coaxial power supply connector. The top end of the stepped power supply column is connected to the center point of the radiating structure, and the bottom end of the stepped power supply column passes through the metal floor and is connected to the top end of the coaxial power supply connector.

[0015] Optionally, the stepped power supply column is arranged in a stepped shape, and the diameter of the stepped power supply column is set to decrease sequentially from top to bottom.

[0016] The beneficial effects of this invention are as follows: This invention proposes a low-profile, dual-band, miniaturized, vertically polarized microstrip antenna with a short-circuit post inductor and a patch capacitor. While maintaining vertical polarization, it achieves a reduction in overall size, with an antenna profile height of only 0.0283λ. Furthermore, this invention is fabricated using a single-layer structure, which effectively reduces the antenna profile height, lowers the complexity of antenna fabrication, and improves antenna stability. It overcomes the challenges of miniaturization and low profile in traditional low-frequency antennas, and maintains dual-band operation capability and good radiation performance while significantly reducing size.

[0017] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a top view schematic diagram of the low-profile miniaturized dual-band antenna based on LC resonant loading described in an embodiment of the present invention; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 This is a cross-sectional view along the centerline of the low-profile miniaturized dual-band antenna based on LC resonant loading described in this embodiment of the invention. Figure 4 for Figure 3 Enlarged view of point B in the middle; Figure 5The antenna's E-plane radiation pattern at 0.851 GHz is shown. Figure 6 The antenna's H-plane radiation pattern at 0.851 GHz is shown. Figure 7 The antenna's E-plane radiation pattern at 1.8 GHz is shown. Figure 8 The antenna's H-plane radiation pattern is shown at 1.8 GHz.

[0020] The markings in the diagram are: 1. Metal ground plane; 2. Dielectric board; 3. Central circular radial patch; 4. First circular patch; 5. Second circular patch; 6. Third circular patch; 7. Central circular pad; 8. Short-circuit post inductor; 9. Capacitor patch; 10. Coaxial feed connector; 11. Stepped feed post. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0022] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] Example 1:

[0024] This embodiment provides a low-profile miniaturized dual-band antenna based on LC resonant loading.

[0025] See Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8The figure shows a low-profile miniaturized dual-band antenna based on LC resonant loading, including: a metal ground plate 1, a dielectric substrate 2, a radiating structure, an LC resonant structure, and a feeding structure. The dielectric substrate 2 is fixedly disposed above the metal ground plate 1; the radiating structure is disposed above the dielectric substrate 2, and the radiating structure is composed of multiple coaxial circular metal patches with multiple through holes; the LC resonant structure is disposed within the through holes of the radiating structure; the feeding structure is disposed on the center line of the radiating structure, and the top end of the feeding structure passes through the dielectric substrate 2 and connects to the radiating structure.

[0026] It is understood that the present invention innovatively integrates a three-layer functional structure for a low-profile miniaturized dual-band antenna based on LC resonant loading: the bottom all-metal floor 1 provides complete grounding and electromagnetic shielding, ensuring that the antenna can be directly installed on a metal carrier (such as a vehicle platform); the dielectric substrate 2 above it achieves an ultra-low profile design of 0.0283λ, which reduces the vertical space occupation compared with the traditional structure; the upper surface of the dielectric substrate 2 forms a rotationally symmetrical radiating structure - the central circular patch 3 and the triple concentric ring patch constitute a multi-resonant unit, which excites dual-band omnidirectional coverage by controlling the size gradient of the annular gap.

[0027] Optionally, the dielectric constant of the dielectric substrate 2 is 2.2 and the loss tangent is 0.003.

[0028] It is understood that the dielectric constant of the present invention is 2.2 and the loss tangent is 0.003, which can reduce the surface wave excitation intensity, improve the radiation efficiency, and suppress the thermal loss of the dielectric.

[0029] Optionally, the radiating structure includes a central circular radiating patch 3, a first annular patch 4, a second annular patch 5, and a third annular patch 6. The central circular radiating patch 3, the first annular patch 4, the second annular patch 5, and the third annular patch 6 are all attached to the upper surface of the dielectric substrate 2. The central circular radiating patch 3 is connected to the feeding structure. The third annular patch 6 is sleeved outside the central circular radiating patch 3. The second annular patch is disposed between the central circular radiating patch 3 and the third annular patch 6. The first annular patch 4 is disposed between the central circular radiating patch 3 and the second annular patch 5.

[0030] It is understood that the radiation structure of the present invention adopts a four-level nested design to achieve compact dual-frequency resonance: the central circular radiation patch 3 is directly connected to the feeding structure as the main excitation source, and the outer periphery is nested in sequence with the first circular patch 4 (loading LC resonant structure), the second circular patch 5 (for extending high frequency bandwidth) and the third circular patch 6 (for extending low frequency current path). The three are isolated by annular gap to form gradient capacitive coupling. This coaxial arrangement combined with rotational symmetry layout can separate the resonant frequency by adjusting the size gradient and achieve 360° omnidirectional coverage.

[0031] Optionally, the central circular radiating patch 3, the first annular patch 4, the second annular patch 5, and the third annular patch 6 have the same thickness, and their central axes are located at the same position.

[0032] It is understood that the thickness uniformity in this invention avoids the distortion of current distribution caused by material thickness differences between patches, while simplifying the manufacturing process; secondly, the strict coaxial layout enhances rotational symmetry and ensures uniform current radiation in the horizontal plane.

[0033] Optionally, each of the central circular radiating patch 3, the first annular patch 4, the second annular patch 5, and the third annular patch 6 has annular gaps between each other.

[0034] It is understood that the present invention adjusts the receiving frequency band by setting the width of the annular gap.

[0035] Optionally, both the first annular patch 4 and the third annular patch 6 are provided with at least six through holes, and each through hole is provided with an LC resonant structure, which is fixedly connected to the inner wall of its corresponding through hole.

[0036] It is understood that the present invention constructs an LC resonant circuit, which, while ensuring a low profile, excites new resonant points in the low-frequency band, effectively realizing the miniaturization of the antenna.

[0037] Optionally, the LC resonant structure includes a central circular pad 7, a short-circuit post inductor 8, and a capacitor patch 9. The central circular pad 7 is fixedly disposed on the dielectric substrate 2. The central axis of the central circular pad 7 and the central axis of the through hole are located on the same straight line. An annular gap is provided between the central circular pad 7 and the through hole. The central circular pad 7 and the through hole are connected by the capacitor patch 9. The two ends of the short-circuit post inductor 8 pass through the dielectric substrate 2 and are respectively connected to the central circular pad 7 and the metal ground plate 1.

[0038] It is understood that the present invention constructs an LC resonant circuit by loading a capacitor patch 9 and a short-circuit post inductor 8 structure onto a conventional circular ring slot coupled antenna. At the same time, multiple circular ring patches work together to generate multiple resonant points. By adjusting the patch size, the antenna can achieve dual-band coverage.

[0039] Optionally, the short-circuit post inductor 8 is a metal post.

[0040] Understandably, the metal shorting post 8 can increase the effective inductance of the antenna, and the capacitor loaded between the circular pad and the ring patch can increase the effective capacitance of the antenna.

[0041] Optionally, the power supply structure includes a stepped power supply column 11 and a coaxial power supply connector 10. The top end of the stepped power supply column 11 is connected to the center point of the radiation structure, and the bottom end of the stepped power supply column 11 passes through the metal floor 1 and is connected to the top end of the coaxial power supply connector 10.

[0042] It is understandable that the geometric center point of the central circular patch 3 is welded to the top of the stepped feed column 11 in this step, so as to ensure that the bottom end of the rotationally symmetric current excitation passes through the metal floor 1 and is connected to the inner conductor of the coaxial feed connector 10 to form a continuous conductive path.

[0043] Optionally, the stepped power supply column 11 is arranged in a stepped shape, and the diameter of the stepped power supply column 11 is set to decrease from top to bottom.

[0044] It is understood that the antenna in this step uses a coaxial feed connector 10 located in the center, and a stepped feed post 11 is loaded on the inner core of the coaxial feed connector 10 to optimize the impedance matching of the antenna.

[0045] It should be noted that the specific manner in which each module performs its operation in the apparatus described in the above embodiments has been described in detail in the embodiments of the method, and will not be elaborated here.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0047] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A low-profile miniaturized dual-band antenna based on LC resonant loading, characterized in that, include: Metal floor (1); Medium plate (2), the medium plate (2) is fixedly installed directly above the metal floor (1); The radiation structure includes a central circular radiation patch (3), a first annular patch (4), a second annular patch (5), and a third annular patch (6) arranged coaxially. The central circular radiation patch (3), the first annular patch (4), the second annular patch (5), and the third annular patch (6) are all attached to the upper surface of the dielectric substrate (2). The central circular radiation patch (3) is connected to the power supply structure. There are annular gaps between each pair of the central circular radiation patch (3), the first annular patch (4), the second annular patch (5), and the third annular patch (6). The first annular patch (4) and the third annular patch (6) are each provided with at least six through holes, and each through hole is provided with an LC resonant structure, which is fixedly connected to the inner wall of its corresponding through hole. The LC resonant structure includes a central circular pad (7), a short-circuit post inductor (8), and a capacitor patch (9). The central circular pad (7) is fixedly disposed on the dielectric substrate (2). The central axis of the central circular pad (7) and the central axis of the through hole are on the same straight line. An annular gap is provided between the central circular pad (7) and the through hole. The central circular pad (7) and the through hole are connected by the capacitor patch (9). The two ends of the short-circuit post inductor (8) pass through the dielectric substrate (2) and are connected to the central circular pad (7) and the metal ground plate (1) respectively. The power supply structure is located on the center line of the radiation structure, and the top of the power supply structure passes through the dielectric plate (2) and is connected to the central circular radiation patch (3).

2. The low-profile miniaturized dual-band antenna based on LC resonant loading according to claim 1, characterized in that... ,include: The dielectric constant of the dielectric substrate (2) is 2.2 and the loss tangent is 0.

003.

3. The low-profile miniaturized dual-band antenna based on LC resonant loading according to claim 1, characterized in that... ,include: The third annular patch (6) is sleeved outside the central circular radiating patch (3), the second annular patch (5) is disposed between the central circular radiating patch (3) and the third annular patch (6), and the first annular patch (4) is disposed between the central circular radiating patch (3) and the second annular patch (5).

4. The low-profile miniaturized dual-band antenna based on LC resonant loading according to claim 3, characterized in that... ,include: The central circular radiating patch (3), the first annular patch (4), the second annular patch (5), and the third annular patch (6) have the same thickness, and their central axes are located at the same position.

5. The low-profile miniaturized dual-band antenna based on LC resonant loading according to claim 1, characterized in that, include: The short-circuit column inductor (8) is a metal column.

6. The low-profile miniaturized dual-band antenna based on LC resonant loading according to claim 1, characterized in that, include: The power supply structure includes a stepped power supply column (11) and a coaxial power supply connector (10). The top end of the stepped power supply column (11) is connected to the center point of the radiation structure, and the bottom end of the stepped power supply column (11) passes through the metal floor (1) and is connected to the top end of the coaxial power supply connector (10).

7. The low-profile miniaturized dual-band antenna based on LC resonant loading according to claim 6, characterized in that, include: The stepped power supply column (11) is arranged in a stepped shape, and the diameter of the stepped power supply column (11) is set to decrease from top to bottom.

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