An electrically small, low profile broadside Huygens source antenna with a helical structure

Abstract

The application discloses a small-electricity low-profile edge-shooting Huygens source antenna with a spiral structure, belongs to the technical field of antennas, and solves the problem of large profile size of a traditional edge-shooting Huygens source antenna; the antenna comprises a first dielectric substrate and a second dielectric substrate which are arranged in a longitudinal stack, an Egyptian battle-axe electric dipole is arranged on the top surface of the first dielectric substrate, a magnetic dipole comprising a plurality of metal spiral structures is arranged on the inner surface of the second dielectric substrate, and two metallized through holes for coupling and feeding the Egyptian battle-axe electric dipole or the magnetic dipole are symmetrically etched at the centers of the first dielectric substrate and the second dielectric substrate. The spiral magnetic dipole adopted in the application is high and low in profile, has the low-profile characteristic itself, and is internally fed through the metallized through hole, so that an additional dielectric layer does not need to be provided to isolate the excitation unit from the antenna, and the longitudinal profile height of the antenna is reduced.

Description

[0001] This invention discloses a low-profile, helical-structured, side-fire Huygens source antenna, belonging to the field of antenna technology, which solves the problem of large cross-sectional dimensions in traditional side-fired Huygens source antennas. It comprises a first dielectric substrate and a second dielectric substrate stacked longitudinally. An Egyptian tomahawk electric dipole is disposed on the top surface of the first dielectric substrate, and a magnetic dipole comprising multiple metal helical structures is disposed on the inner surface of the second dielectric substrate. Two metallized vias are symmetrically etched at the centers of the first and second dielectric substrates for coupling and feeding the Egyptian tomahawk electric dipole or the magnetic dipole. The helical magnetic dipole used in this invention has a low height and inherently low cross-sectional characteristics. Furthermore, it is fed internally through the metallized vias, eliminating the need for an additional dielectric layer to isolate the excitation element from the antenna, thus reducing the antenna's longitudinal cross-sectional height. Technical Field

[0002] This invention relates to the field of antenna technology, and specifically to an electrically small, low-profile side-firing Huygens source antenna with a helical structure. Background Technology

[0003] A Huygens source antenna (also known as an electromagnetic dipole antenna) consists of a pair of complementary electric and magnetic dipoles. It can form stable directional radiation in the far field without relying on metal reflection, achieving a good front-to-back ratio.

[0004] Depending on the direction of directional radiation, Huygens source antennas are divided into side-fire and end-fire types. Compared with end-fire Huygens source antennas, side-fire Huygens source antennas have a radiation direction perpendicular to the substrate and a lower profile in the direction of the main beam, making them suitable for wireless applications such as wearable communication devices and radio frequency identification.

[0005] Traditional side-fire Huygens source antennas consist of a magnetic dipole composed of two vertical metal walls and a metal ground plane. The height of these metal walls is 0.25 times the wavelength, making the overall Huygens source antenna structure rather bulky. Researchers have already used open-loop resonators as magnetic dipoles, reducing the cross-sectional size of side-fire Huygens source antennas to 0.045 times the wavelength. However, in these antennas, the excitation element is located outside the magnetic dipole antenna, requiring an additional dielectric substrate to separate the magnetic dipole from the excitation element to prevent short circuits, which increases the overall antenna cross-section to some extent. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention provides an electrically small, low-profile side-fire Huygens source antenna with a spiral structure, which solves the problem of large profile size in traditional side-fire Huygens source antennas.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A low-profile, helical Huygens source antenna with a small electrical profile is provided, comprising a first dielectric substrate and a second dielectric substrate stacked longitudinally. An Egyptian tomahawk electric dipole is provided on the top surface of the first dielectric substrate, and a magnetic dipole comprising a plurality of metal helical structures is provided on the inner surface of the second dielectric substrate. Two metallized through holes for coupling and feeding the Egyptian tomahawk electric dipole and the magnetic dipole are symmetrically etched at the center of the first dielectric substrate and the second dielectric substrate, respectively.

[0009] In this scheme, the spiral magnetic dipole has a low height and low profile characteristics. Furthermore, it is fed internally through a metallized via, eliminating the need for an additional dielectric layer to isolate the excitation unit from the antenna. This further reduces the antenna's longitudinal profile height to only 0.032 times the wavelength.

[0010] Furthermore, the magnetic dipole comprises four metal spiral structures, each in the shape of a three-dimensional rectangular helix. The four metal spiral structures are symmetrical about the center line of the second dielectric substrate, and the normal vector of each metal spiral structure is parallel to the X-axis.

[0011] In this scheme, a single metal spiral structure can be regarded as a normal mode spiral antenna, whose radiation characteristics are the same as those of an electric dipole and cannot be used as a magnetic dipole. However, this scheme arranges four spiral antennas symmetrically, so that the electric dipole effects of the four spiral antennas cancel each other out, and the whole structure exhibits the radiation characteristics of a magnetic dipole.

[0012] Furthermore, the metal spiral structure includes five metal vias etched on the second dielectric substrate and four rectangular metal patches. The five metal vias are distributed in a W-shape with five endpoints. The four metal patches are located at the upper and lower ends of the metal vias in pairs, and connect the five metal vias sequentially. The metal patches and metal vias serve as the long and short sides of the three-dimensional rectangular spiral, respectively.

[0013] Furthermore, the spiral diameter D1 of the metal spiral structure is 3mm, the pitch S2 is 1.34mm, the number of spiral turns is 2, and the included angle between the metal patch located at the upper end of the metal through hole and the metal patch located at the lower end of the metal through hole is 12.58°.

[0014] Furthermore, the length L2 of the metal patch is 3.87 mm, the width W3 is 0.8 mm, and the radius R4 of the metal through hole is 0.2 mm.

[0015] Furthermore, the radius of the metallized via is 0.3 mm.

[0016] Furthermore, the Egyptian tomahawk electric dipole includes a first tomahawk metal patch and a second tomahawk metal patch symmetrically disposed on a first dielectric substrate.

[0017] Furthermore, both the first and second tomahawk metal patches are etched with circular grooves concentric with the metallized vias. These circular grooves are used to prevent short circuits between the power-feeding metal vias and the electric dipoles.

[0018] Furthermore, the first and second tomahawk metal patches have the same structure. The straight edge length L1 of the first tomahawk metal patch is 7.8 mm, the width W1 is 1.5 mm, the outer arc radius R2 is 7.9 mm, the arc width W2 is 0.52 mm, and the gap between the first and second tomahawk metal patches is 0.2 mm.

[0019] Furthermore, both the first and second dielectric substrates are made of F4BM265, with a relative permittivity of 2.65, a relative permeability of 1, and a loss tangent of 0.0015. The thickness of the first dielectric substrate is 0.5 mm, and the thickness of the second dielectric substrate is 1.5 mm.

[0020] This invention discloses an electrically small, low-profile side-firing Huygens source antenna with a helical structure, the advantages of which are:

[0021] The spiral magnetic dipole used in this invention has a low height and low profile characteristics. Furthermore, it is fed internally through a metallized via, eliminating the need for an additional dielectric layer to isolate the excitation unit from the antenna, thus reducing the antenna's longitudinal profile height. Attached Figure Description

[0022] Figure 1 A schematic diagram of an electrically small, low-profile side-firing Huygens source antenna with a spiral structure;

[0023] Figure 2 This is a schematic diagram of the front side of the first dielectric substrate;

[0024] Figure 3 This is a schematic diagram of the back side of the second dielectric substrate;

[0025] Figure 4 This is a three-dimensional schematic diagram of a metal spiral structure;

[0026] Figure 5 This is a schematic diagram of the front side of the second dielectric substrate;

[0027] Figure 6 This is a schematic diagram of the back side of the second dielectric substrate;

[0028] Figure 7 The image shows the S-parameter curve of the antenna's reflection coefficient.

[0029] Figure 8 The radiation pattern of the antenna's E-plane is shown.

[0030] Figure 9The radiation pattern of the antenna's H-plane;

[0031] Wherein: 0-1, first dielectric substrate; 0-2, second dielectric substrate; 1, Egyptian tomahawk electric dipole; 2, magnetic dipole; 1-1-1, first tomahawk metal patch; 1-1-2, second tomahawk metal patch; 1-2, metallized through hole; 1-3, circular groove; 2-1, metal spiral structure; 2-1-1, metal patch; 2-1-2, metal through hole; 2-2, conductive patch. Detailed Implementation

[0032] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0033] This embodiment provides an electrically small, low-profile side-fire Huygens source antenna with a spiral structure to solve the problem of large profile size of traditional side-fire Huygens source antennas.

[0034] refer to Figure 1 A low-profile, side-firing Huygens source antenna with a spiral structure includes a first dielectric substrate 0-1 and a second dielectric substrate 0-2 stacked longitudinally. The first dielectric substrate 0-1 is located above the second dielectric substrate, and the top view projections of the first dielectric substrate 0-1 and the second dielectric substrate 0-2 are both circular.

[0035] Preferably, refer to Figure 2 In this embodiment, the first dielectric substrate 0-1 and the second dielectric substrate 0-2 are both made of F4BM265, with a relative permittivity of 2.65, a relative permeability of 1, and a loss tangent of 0.0015. The radius R1 of the first dielectric substrate 0-1 and the second dielectric substrate 0-2 is 11mm. The thickness of the first dielectric substrate 0-1 is 0.5mm, and the thickness of the second dielectric substrate 0-2 is 1.5mm.

[0036] An Egyptian tomahawk electric dipole 1 is provided on the top surface of the first dielectric substrate 0-1, and a magnetic dipole 2 including multiple metal spiral structures 2-1 is provided on the inner surface of the second dielectric substrate 0-2.

[0037] refer to Figure 2 and Figure 3 Two metallized vias 1-2 are symmetrically etched at the center of the first dielectric substrate 0-1 and the second dielectric substrate 0-2, respectively, for coupling and feeding the Egyptian tomahawk electric dipole 1 and the magnetic dipole 2.

[0038] Preferably, the radius of each of the four metallized through holes 1-2 is 0.3 mm.

[0039] In this embodiment, the spiral magnetic dipole 2 has a low height and low profile characteristics. Furthermore, it is internally fed through the metallized vias 1-2, eliminating the need for an additional dielectric layer to isolate the excitation unit from the antenna. This further reduces the longitudinal profile height of the antenna to only 0.032 times the wavelength.

[0040] Preferably, the Egyptian tomahawk electric dipole 1 in this embodiment includes a first tomahawk metal patch 1-1-1 and a second tomahawk metal patch 1-1-2 symmetrically disposed on a first dielectric substrate 0-1.

[0041] refer to Figure 2 The first tomahawk metal patch 1-1-1 and the second tomahawk metal patch 1-1-2 have the same structure. The straight edge length L1 of the first tomahawk metal patch 1-1-1 is 7.8 mm, the width W1 is 1.5 mm, the outer arc radius R2 is 7.9 mm, and the arc width W2 is 0.52 mm. The gap between the first tomahawk metal patch 1-1-1 and the second tomahawk metal patch 1-1-2 is 0.2 mm. This structure of the first tomahawk metal patch 1-1-1 and the second tomahawk metal patch 1-1-2 makes the resonant point of the tomahawk electric dipole near 5 GHz.

[0042] As a further embodiment, both the first tomahawk metal patch 1-1-1 and the second tomahawk metal patch 1-1-2 are etched with circular grooves 1-3 concentric with the metallized through-hole 1-2. Preferably, the circular grooves 1-3 are used to avoid a short circuit between the power supply metal through-hole 2-1-2 and the electric dipole.

[0043] As a further embodiment, the magnetic dipole 2 includes four metal spiral structures 2-1, each of which is a three-dimensional rectangular helix. The four metal spiral structures 2-1 are symmetrical about the center line of the second dielectric substrate 0-2, and the normal vector of each metal spiral structure 2-1 is parallel to the X-axis.

[0044] In this embodiment, reference Figure 1 The X-axis, Y-axis and Z-axis are perpendicular to each other to form a three-dimensional rectangular coordinate system, where the X-axis and Y-axis are oriented along the two directions of the center line of the second dielectric substrate 0-2, respectively.

[0045] A single metal spiral structure 2-1 can be regarded as a normal mode spiral antenna, and its radiation characteristics are the same as those of an electric dipole. It cannot be used as a magnetic dipole 2. However, this scheme arranges four spiral antennas symmetrically, so that the electric dipole effects of the four spiral antennas cancel each other out, and the whole structure exhibits the radiation characteristics of a magnetic dipole 2.

[0046] As a further solution in this embodiment, refer to Figure 4 The metal spiral structure 2-1 includes five metal through holes 2-1-2 etched on the second dielectric substrate 0-2 and four rectangular metal patches 2-1-1. The five metal through holes 2-1-2 are distributed in a W-shape with five endpoints. The four metal patches 2-1-1 are located in pairs at the upper and lower ends of the metal through holes 2-1-2, and connect the five metal through holes 2-1-2 in sequence. The metal patches 2-1-1 and the metal through holes 2-1-2 serve as the long side and short side of the three-dimensional rectangular spiral, respectively.

[0047] Preferably, refer to Figure 5 The metal spiral structure 2-1 has a spiral diameter D1 of 3mm, a pitch S2 of 1.34mm, and 2 spiral turns. The included angle between the metal patch 2-1-1 located at the upper end of the metal through hole 2-1-2 and the metal patch 2-1-1 located at the lower end of the metal through hole 2-1-2 is 12.58°. The length L2 of the metal patch 2-1-1 is 3.87mm, the width W3 is 0.8mm, the radius R4 of the metal through hole 2-1-2 is 0.2mm, and the radius R5 of the metal through hole 2-1-2 is 0.3mm.

[0048] As a further solution in this embodiment, refer to Figure 6 Two conductive patches 2-2 are provided at the two metallized through holes 1-2 on the bottom of the second dielectric substrate 0-2, which are connected to the external power supply circuit. Both conductive patches 2-2 are rectangular with the same structure. Preferably, in this embodiment, the conductive patch 2-2 has a length L3 of 1.9 mm and a width W4 of 1 mm.

[0049] refer to Figure 7 , Figure 7 The graph shows the reflection coefficient S-parameter as a function of frequency obtained from the simulation of this invention. In this embodiment, the antenna resonant frequency is 4.844 GHz, and the reflection coefficient is... 20.9dB 10dB bandwidth 18.7MHz (4.8360GHz) (4.8547GHz), which can cover the 5G frequency band.

[0050] refer to Figure 8 and Figure 9 , Figure 8 and Figure 9 The images show the radiation patterns of the electrically small planar Huygens source antenna simulated in this embodiment at the resonant frequency of 4.844 GHz in the E-plane and H-plane, respectively.

[0051] In this embodiment, the E-plane is the antenna electrical plane, i.e. Figure 1 The XOZ plane is the antenna magnetic plane; the H plane is the antenna magnetic plane, i.e. Figure 1 The YOZ plane in the middle.

[0052] Figure 8 and Figure 9 This reflects that the antenna of this embodiment has end-fire characteristics. At the resonant frequency, the maximum gain of the antenna is 3.32 dBi, the front-to-back ratio is 15.01, and the radiation efficiency is 77.1%. It can be seen that the antenna of this embodiment has the advantages of compact structure and low profile, while having good radiation performance.

[0053] Although specific embodiments of the invention have been described in detail with reference to the accompanying drawings, this should not be construed as limiting the scope of protection of this patent. Various modifications and variations that can be made by a person skilled in the art without inventive effort within the scope described in the claims still fall within the scope of protection of this patent.

Claims

1. An electrically small, low profile broadside Huygens source antenna having a helical structure, characterized by: The first dielectric substrate (0-1) and the second dielectric substrate (0-2) are arranged in a longitudinal stack, the top surface of the first dielectric substrate (0-1) is provided with an Egyptian battle-axe electric dipole (1), the inner surface of the second dielectric substrate (0-2) is provided with a magnetic dipole (2) comprising a plurality of metal spiral structures, and the center of the first dielectric substrate (0-1) and the second dielectric substrate (0-2) is respectively symmetrically etched with two metallized through holes (1-2) for coupling and feeding the Egyptian battle-axe electric dipole (1) and the magnetic dipole (2); The magnetic dipole (2) comprises four metal spiral structures (2-1) each in the shape of a three-dimensional rectangular spiral line, the four metal spiral structures (2-1) are mutually symmetrical about the center line of the second dielectric substrate (0-2), and the normal vector of each metal spiral structure (2-1) is parallel to the X-axis, the X-axis, the Y-axis and the Z-axis form a three-dimensional orthogonal coordinate system, wherein the directions of the X-axis and the Y-axis are along two directions of the center line of the second dielectric substrate (0-2) respectively. The metal spiral structure (2-1) comprises five metal through holes (2-1-2) etched on the second dielectric substrate (0-2) and four rectangular metal patches (2-1-1), the five metal through holes (2-1-2) are distributed in the shape of a W with five end points respectively, and the four metal patches (2-1-1) are two by two in a group and are located at the upper and lower ends of the metal through holes (2-1-2) respectively and sequentially connect and conduct the five metal through holes (2-1-2), and the metal patch (2-1-1) and the metal through hole (2-1-2) are respectively the long side and the short side of the three-dimensional rectangular spiral line.

2. The antenna according to claim 1, characterized in that: The spiral diameter D1 of the metal spiral structure (2-1) is 3mm, the pitch S2 is 1.34mm, the number of turns is 2, and the included angle between the metal patch (2-1-1) located at the upper end of the metal through hole (2-1-2) and the metal patch (2-1-1) located at the lower end of the metal through hole (2-1-2) is 12.58°.

3. The antenna of claim 2, wherein: The length L2 of the metal patch (2-1-1) is 3.87mm, the width W3 is 0.8mm, and the radius R4 of the metal through hole (2-1-2) is 0.2mm.

4. The antenna of claim 1, wherein: The radius of the metallized through hole (1-2) is 0.3mm.

5. The antenna according to claim 1, characterized in that: The Egyptian battle-axe electric dipole (1) comprises a first battle-axe metal patch (1-1-1) and a second battle-axe metal patch (1-1-2) symmetrically arranged on the first dielectric substrate (0-1).

6. The antenna according to claim 5, characterized in that: The first battle-axe metal patch (1-1-1) and the second battle-axe metal patch (1-1-2) are each etched with a circular groove (1-3) with the same center as the metallized through hole (1-2).

7. The antenna of claim 5, wherein: The first war axe metal patch (1-1-1) and the second war axe metal patch (1-1-2) are structurally identical, the straight edge length L1 of the first war axe metal patch (1-1-1) is 7.8 mm, the width W1 is 1.5 mm, the outer circle arc edge radius R2 is 7.9 mm, the arc edge width W2 is 0.52 mm, and the gap between the first war axe metal patch (1-1-1) and the second war axe metal patch (1-1-2) is 0.2 mm.

8. The antenna according to any of claims 1-7, characterized by: The material of the first dielectric substrate (0-1) and the second dielectric substrate (0-2) is F4BM265, the relative dielectric constant is 2.65, the relative permeability is 1, and the loss tangent angle is 0.0015; the thickness of the first dielectric substrate (0-1) is 0.5 mm, and the thickness of the second dielectric substrate (0-2) is 1.5 mm.

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