A broadband magnetoelectric dipole loaded with a double-ring structure

Abstract

The present invention provides a broadband magnetoelectric dipole loaded with a double-ring structure, which includes an electric dipole composed of four square patches. Four cylinders and Γ-shaped probes are placed in the middle of the four square patches. The Γ-shaped probes, the four cylinders and the ground plane between the cylinders form a magnetic dipole. Two first metal rings are symmetrically fixed on the outer sides of the electric dipole, and a second metal ring is respectively arranged on the inner sides of the first metal rings; gaps are provided on the outer sides of the first metal rings and the second metal rings. By loading two pairs of metal rings with different radii on both sides of the antenna, the present invention generates a new resonance point in each of the high-frequency region and the low-frequency region, thereby greatly increasing the bandwidth of the antenna. The impedance bandwidth of this antenna increases by 79.7%, that is, from 48.3% to 86.8%. At the same time, other excellent characteristics are maintained, such as high gain, low cross polarization and stable radiation pattern. The antenna has a simple structure and realizes broadband and high gain at the same time.

Description

Technical Field

[0001] The present invention belongs to the field of broadband magnetoelectric dipole antennas, and particularly relates to a broadband magnetoelectric dipole loaded with a double-ring structure. Background Art

[0002] With the rapid development of new technologies, as the front-end of wireless devices, antennas are required to exhibit a wider bandwidth to support the increasing data rate requirements. As a typical broadband antenna, the magnetoelectric dipole antenna has been widely studied due to its excellent characteristics such as high gain, low cross-polarization (CRPL), and a stable radiation pattern within a wide operating frequency range. Professor Luk first proposed in 2006 that the magnetoelectric dipole antenna consists of a half-wavelength electric dipole and a quarter-wavelength magnetic dipole placed orthogonally. Through this structure, not only can a 45% bandwidth be obtained, but also almost the same heart-shaped radiation pattern can be obtained in both the E and H planes, making it an ideal choice for various applications.

[0003] Generally, modifying the two parts of the magnetoelectric dipole antenna, namely the main radiation structure and the feeding structure, can produce a wider bandwidth. In the state-of-the-art technologies, various broadband magnetoelectric dipole antennas have been studied. However, although they have a relatively wide bandwidth, the antenna structures are complex, the cost is high, and the manufacturing difficulty is also greatly increased.

[0004] Therefore, in order to improve the impedance bandwidth of the magnetoelectric dipole antenna, a broadband magnetoelectric dipole loaded with a double-ring structure is proposed. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a broadband magnetoelectric dipole loaded with a double-ring structure to solve the problems mentioned in the above background art in view of the deficiencies of the above-mentioned prior art.

[0006] To solve the above technical problem, the technical solution adopted by the present invention is: a broadband magnetoelectric dipole loaded with a double-ring structure, including an electric dipole composed of four square patches, four cylinders and a Γ-shaped probe are placed in the middle of the four square patches, and the Γ-shaped probe, the four cylinders and the ground between the cylinders form a magnetic dipole;

[0007] Two first metal rings are symmetrically fixed on the outside of the electric dipole, and a second metal ring is respectively arranged on the inner side of the first metal rings;

[0008] The outside of the first metal ring and the second metal ring is provided with a notch.

[0009] Further, the length L of the square patch is 30 mm, and the gap S between the four square patches is 6.5 mm.

[0010] Further, the width Fw of the Γ-shaped probe is 4.8 mm, the radius of the cylinder is 4.5 mm, and the height H is 30 mm.

[0011] Further, the radius R1 of the first metal ring is 12 mm, the radius R2 of the second metal ring is 6.2 mm, and the thickness W of the first metal ring and the second metal ring is 1.5 mm.

[0012] Further, the size c of the notch is 1 mm.

[0013] The present invention has the following advantages compared with the prior art:

[0014] By loading two pairs of metal rings with different radii on both sides of the antenna, the present invention generates a new resonance point in each of the high-frequency region and the low-frequency region, thereby greatly increasing the bandwidth of the antenna. The relative bandwidth of the antenna reaches 86.8%. When S11 ≤ -10 dB, the operating frequency range of the antenna is 1.465 - 3.71 GHz. In the entire operating frequency range, the antenna gain range is 7.42 - 12.8 dBi. In the entire operating frequency range, the antenna has a stable radiation pattern, a cross-polarization level less than -22 dB, and a front-to-back ratio greater than 15 dB. The antenna structure is simple, maintaining high gain, low cross-polarization, and a stable radiation pattern, while achieving broadband and high gain, and having a low processing cost, and can be widely applied. Description of the Drawings

[0015] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0016] Figure 2 is the S11 curve graph and gain graph of Antenna 1, Antenna 2, and Antenna 3 in the present invention embodiment at 1 - 4 GHz;

[0017] Figure 3 is the real and imaginary part impedance graph of Antenna 1, Antenna 2, and Antenna 3 in the present invention embodiment; where Re is the real part and Im is the imaginary part;

[0018] Figure 4 is the graph of the influence of different R2 of Antenna 3 on the simulated input resistance in the present invention embodiment;

[0019] Among them, (a) is the graph of the influence of different R2 of Antenna 3 on the simulated input resistance, and (b) is the graph of the influence of different R2 of Antenna 3 on the S11 curve

[0020] Figure 5 is the surface current distribution graph of the magnetoelectric dipole antenna of the present invention;

[0021] Among them, (a) is 1.6 GHz, (b) is 2.3 GHz, (c) is 3.2 GHz, and (d) is 3.65 GHz;

[0022] Figure 6 are the S11 curve graph and gain graph of the magnetoelectric dipole antenna of the present invention;

[0023] Figure 7 is the radiation pattern of the magnetoelectric dipole antenna of the present invention;

[0024] Among them, (a) is 1.6 GHz, (b) is 2.3 GHz, (c) is 3.2 GHz, and (d) is 3.6 GHz.

[0025] Explanation of reference numerals:

[0026] 1 - square patch; 2 - cylinder; 3 - first metal ring; 4 - second metal ring; 5 - Γ - shaped probe; 6 - box - shaped reflector. Detailed implementation manners

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0028] As Figure 1 shown, the present invention provides a technical solution: a broadband magnetoelectric dipole loaded with a double - ring structure, including an electric dipole composed of four square patches 1. Four cylinders 2 and Γ - shaped probes 5 are placed in the middle of the four square patches 1. The Γ - shaped probes 5, the four cylinders 2, and the ground between the cylinders 2 form a magnetic dipole, forming antenna 1.

[0029] Two first metal rings 3 are symmetrically fixed on the outside of the electric dipole, and a new resonance point of about 1.6 GHz appears in the low - frequency region, forming antenna 2.

[0030] A second metal ring 4 is respectively arranged on the inner side of the first metal ring 3; a new resonance point of about 3.6 GHz appears in the high - frequency region. Introducing two pairs of metal rings with different radii can increase the working bandwidth. Notches are arranged on the outer sides of the first metal ring 3 and the second metal ring 4, forming antenna 3.

[0031] The electric dipole, magnetic dipole, and the first metal ring 3 and the second metal ring 4 are placed in a box - shaped reflector 6 to reduce the back - radiation; the box - shaped reflector 6 is specifically a box with an open top with side length G×G and height H.

[0032] The length L of the square patch 1 is 30 mm, and the gap S between the four square patches 1 is 6.5 mm.

[0033] The width Fw of the Γ-shaped probe 5 is 4.8 mm, the radius R3 of the cylinder 2 is 4.5 mm, and the height of the magnetic dipole is the same as the height H of the box-shaped reflector 6, where H is 30 mm.

[0034] The radius R1 of the first metal ring 3 is 12 mm, the radius R2 of the second metal ring 4 is 6.2 mm, and the thickness W of the first metal ring 3 and the second metal ring 4 is 1.5 mm. The size c of the notch is 1 mm.

[0035] Figure 2 They are the S11 curve graphs and gain graphs of Antenna 1, Antenna 2, and Antenna 3 in the range of 1 - 4 GHz during the antenna design process, as Figure 2 shown. Antenna 1 has two resonance points, approximately at 2.3 GHz and 3.0 GHz respectively. The relative bandwidth of this antenna is 48.3%, and the operating frequency range of the antenna when S11 ≤ -10 dB is 1.98 - 3.24 GHz.

[0036] A pair of first metal rings 3 with a radius of R1 is loaded outside Antenna 1, and the synthesized antenna is called Antenna 2. A new resonance point approximately at 1.6 GHz appears in the low-frequency region of Antenna 2. A pair of second metal rings 4 with a radius of R2 is further loaded inside the metal ring with a radius of R1 in Antenna 2, and the synthesized antenna is called Antenna 3. A new resonance point approximately at 3.6 GHz appears in the high-frequency region of Antenna 3. The resonance point at 3.0 GHz related to the electric dipole moves to approximately 3.2 GHz after loading the second pair of metal rings. The relative bandwidth of this antenna is 86.8%, and the operating frequency range of the antenna when S11 ≤ -10 dB is 1.465 - 3.71 GHz. The antenna gain after loading is still around 8.5 dBi.

[0037] Figure 3 They are the input impedance graphs of Antenna 1, Antenna 2, and Antenna 3, as Figure 3 shown. Antenna 1 has relatively large inductance around 1.6 GHz and 3.6 GHz, resulting in antenna impedance mismatch. After loading a pair of metal rings with a radius of R1 on Antenna 2, the inductance in the low-frequency region of Antenna 2 decreases, and the imaginary part of the input impedance of Antenna 2 in the low-frequency region decreases from 60 Ω to 0 Ω. After loading the second metal ring 4 with a radius of R2 inside the first metal ring 3 on Antenna 3, the inductance in the high-frequency region of Antenna 3 decreases, and the imaginary part of the input impedance of Antenna 3 in the high-frequency region decreases from 140 Ω to 0 Ω.

[0038] Therefore, by loading two pairs of metal rings, not only does the fluctuation of the imaginary part become gentle, but also the real part of the input impedance is closer to 50 Ω, resulting in a wider impedance bandwidth.

[0039] Figure 4 This is the influence of metal ring R2 on the simulated input resistance and the S11 curve. As Figure 4 shown, R2 has a great influence on the resonance mode of antenna 3 in the frequency range of 3 - 4 GHz, while it has almost no influence in the frequency range of 1 - 3 GHz, causing the resonance point at 3 GHz in antenna 3 to move to 3.2 GHz.

[0040] Figure 5 This is the surface current distribution diagram of antenna 3 at four points: 1.6 GHz, 2.3 GHz, 3.2 GHz, and 3.65 GHz. As Figure 5 shown, in Figure 5 (a), at 1.6 GHz, the current on the two pairs of metal rings is very strong and in the same direction. In Figure 5 (b), at 2.3 GHz, the current distribution on the horizontal patch is weak, and at this time, mainly magnetic dipoles are working. In Figure 5 (c), at 3.2 GHz, the current on the metal ring with radius R2 and the electric dipole is very strong, and their current directions are opposite. In Figure 5 (d), at 3.65 GHz, the current on the electric dipole and the two pairs of metal rings is very strong. The current direction of the electric dipole is the same as that of the pair of metal rings with radius R2 and opposite to that of the pair of metal rings with radius R1.

[0041] Figure 6 This is the S11 curve diagram and gain diagram of the antenna. As Figure 6 shown, the relative bandwidth of the antenna is 86.8%. When S11 ≤ - 10 dB, the operating frequency range of the antenna is 1.465 - 3.71 GHz. Within the operating frequency range, the antenna gain is about 8.5 dBi.

[0042] Figure 7 This is the radiation pattern of the antenna at 1.6 GHz, 2.3 GHz, 3.2 GHz, and 3.6 GHz. As Figure 7 shown, at 1.6 GHz and 2.3 GHz, almost the same pattern is obtained in the E - plane and H - plane. At 3.2 GHz and 3.6 GHz, the beam width of the H - plane pattern is slightly narrower. The cross - polarization (CRPL) of the antenna is less than - 22 dB and the front - to - back ratio (FBR) is greater than 15 dB within the entire operating frequency band.

[0043] From the analysis of the simulation results:

[0044] 1. The software platform for the simulation experiment of the present invention is Ansoft HFSS electromagnetic simulation software.

[0045] 2. The relative bandwidth of the antenna (S11 ≤ -10 dB) is increased from 48.3% (operating frequency band 1.98 - 3.24 GHz) to 86.8% (operating frequency band 1.465 - 3.71 GHz), that is, the bandwidth is increased by 79.7%. The antenna gain range is 7.42 - 12.8 dBi within the entire operating frequency range. Thus, it can be seen that the present invention achieves both broadband and high gain simultaneously.

[0046] The above simulation results verify the correctness, effectiveness, and reliability of the present invention.

[0047] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0048] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A broadband magnetoelectric dipole with a loaded double-ring structure, characterized in that: An electric dipole composed of four square patches (1), with a cylinder (2) fixed to the bottom surface of each square patch (1), and a Γ-shaped probe (5) placed between the four square patches (1). The Γ-shaped probe (5), the four cylinders (2), and the ground plane between the cylinders (2) form a magnetic dipole; Two first metal rings (3) are symmetrically fixed to the outside of the electric dipole, and a second metal ring (4) is respectively arranged on the inner sides of the first metal rings (3); The electric dipole, the magnetic dipole, and the first metal rings (3) and the second metal rings (4) are placed in a box-shaped reflector (6) to reduce the back radiation; The box-shaped reflector (6) is specifically a box with an open top and side lengths of G×G and a height of H; There are notches on the outer sides of the first metal rings (3) and the second metal rings (4).

2. The broadband magnetoelectric dipole with a loaded double-ring structure according to claim 1, characterized in that, The length L of the square patch (1) is 30 mm, and the gap S between the four square patches (1) is 6.5 mm.

3. The broadband magnetoelectric dipole with a loaded double-ring structure according to claim 1, characterized in that, The width Fw of the Γ-shaped probe (5) is 4.8 mm, the radius of the cylinder (2) is 4.5 mm, and the height of the magnetic dipole is the same as the height H of the box-shaped reflector (6), and H is 30 mm.

4. The broadband magnetoelectric dipole with a loaded double-ring structure according to claim 1, characterized in that, The radius R1 of the first metal ring (3) is 12 mm, the radius R2 of the second metal ring (4) is 6.2 mm, and the thickness W of the first metal rings (3) and the second metal rings (4) is 1.5 mm.

5. The broadband magnetoelectric dipole with a loaded double-ring structure according to claim 1, characterized in that, The size c of the notch is 1 mm.

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