Multi-mode resonance MNZ annular Wi-Fi antenna applied to tablet computer

Abstract

The invention discloses a multi-mode resonance MNZ annular Wi-Fi antenna applied to a tablet computer, particularly relates to the technical field of microwave communication, and solves the problem that in the prior art, Wi-Fi antennas used by a super-traditional all-metal shell terminal can be divided into inverted-F antennas, slot antennas, microstrip patch antennas and the like. However, the bandwidth of a Wi-Fi antenna realized by using a traditional method is very limited, and most of the Wi-Fi antennas cannot completely cover all frequency bands in a Wi-Fi (Wireless Fidelity) protocol and a Wi-Fi (Wireless Fidelity) protocol. According to the technical scheme, the mode wavelength is controlled by using the change of magnetic conductivity, and finally, a plurality of resonant modes are reasonably coupled under the same physical size, so that the multimode resonant MNZ loop antenna with the broadband characteristic is realized; according to the invention, full coverage of three frequency bands in a Wi-Fi (Wireless Fidelity) 6 protocol and a Wi-Fi 6E protocol is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave communications, and in particular to a multi-mode resonant MNZ ring Wi-Fi antenna applied to a tablet computer. Background Art

[0002] As an important part of modern wireless mobile devices, tablets are used in various scenarios due to their portability and handwriting convenience. The main way of wireless communication for tablets is Wi-Fi, and the latest generation of wireless LAN standard is Wi-Fi 6, whose protocol standard covers 2.4GHz (2.4-2.484GHz) and 5GHz (5.13-5.83GHz) frequency bands. Subsequently, Wi-Fi6E expanded the frequency band to 6GHz (5.925-7.125GHz) to enhance the communication bandwidth. For tablets, users require that their borders must be simple and beautiful, and that the full metal frame must be continuously wrapped without breakpoints, which means that the traditional method of using the tablet frame to build Wi-Fi can no longer be used by us. In order to solve this problem, we took into account the easily overlooked area of ​​the tablet rear camera part, which happens to provide a certain space for the design of the Wi-Fi antenna, and the antenna designed here can also achieve the continuity of the tablet metal frame wrapping.

[0003] Traditional border line antennas are favored by users and antenna designers because they are easy to integrate and achieve broadband. However, this type of antenna cannot meet the new requirement of tablet computers to achieve continuous wrapping of the metal frame. Therefore, we can only use some microstrip antennas integrated inside the tablet computer to achieve this new requirement. Traditional implementation methods include inverted F antennas, slot antennas, microstrip patch antennas, etc., but the bandwidth of Wi-Fi antennas implemented using these methods is very limited, and most of them cannot fully cover all frequency bands within the Wi-Fi6 and Wi-Fi6E protocols. Therefore, the research on antenna design that can fully cover all frequency bands within the Wi-Fi6 / 6E protocol and ensure the continuity of the tablet computer's metal frame has both important theoretical significance and high engineering application value. Summary of the invention

[0004] Therefore, the present invention solves the technical problem that the Wi-Fi antennas used in all-metal shell terminals in the prior art can be divided into inverted F antennas, slot antennas, microstrip patch antennas and other types, but the bandwidth of Wi-Fi antennas implemented by traditional methods is very limited, and most of them cannot fully cover all frequency bands within the Wi-Fi 6 and Wi-Fi 6E protocols; the present invention provides a multi-mode resonant MNZ ring Wi-Fi antenna for tablet computers, which has a simple structure, a wide coverage bandwidth, and each frequency point is easy and flexible to adjust.

[0005] The present invention provides a multi-mode resonant MNZ ring Wi-Fi antenna for tablet computers, comprising a metal frame, an antenna substrate and a metal ground arranged in sequence from top to bottom; an MNZ segmented ring antenna and a semi-ring microstrip antenna are arranged on the antenna substrate, and a coaxial feeding structure is arranged on the lower surface of the antenna substrate. The MNZ segmented ring antenna is connected to the metal ground through a metallized hole; MNZ is Mu-Near-Zero, which means that the effective magnetic permeability is near zero.

[0006] Furthermore, the antenna substrate is composed of a first substrate and a second substrate of different sizes. The first substrate is smaller than the second substrate and is located on the upper surface of the second substrate, and the first substrate is in the middle area of ​​the width direction of the second substrate. The coaxial feeding structure passes through the second substrate upward. A metal column is provided on the antenna substrate, and the metal column passes through the antenna substrate and the metal ground. The metal column simulates the influence of a metal camera on antenna performance.

[0007] Furthermore, the MNZ segmented loop antenna disposed on the antenna substrate is used as a main patch. The semi-loop microstrip antenna generates a resonant mode covering 2.4-2.484 GHz in the low frequency band through magnetic coupling, and adds two resonance points in the high frequency band.

[0008] Furthermore, a MNZ segmented loop antenna and a semi-ring microstrip antenna are provided on the upper surface of the first substrate and between the first substrate and the second substrate; the MNZ segmented loop antenna and the semi-ring microstrip antenna on the upper surface of the first substrate extend to the side of the first substrate and are connected to the MNZ segmented loop antenna and the semi-ring microstrip antenna between the first substrate and the second substrate. The metal ground is larger than the antenna substrate and the metal frame. In order to simulate the internal environment of a tablet computer, the entire antenna structure uses a large metal ground and there is a metal frame surrounding the radiation structure on the periphery. Since the size of the metal frame has little effect on the antenna performance, a frame similar in size to the antenna substrate is used to simulate the internal environment of the tablet.

[0009] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0010] 1. The present invention provides a multi-mode resonant MNZ ring Wi-Fi antenna for a tablet computer, which adopts a MNZ segmented ring antenna structure. In addition to the 0th order mode of the antenna, the 1 / 2 / 3 / 4 modes of the MNZ antenna are also utilized, and flexible control between the modes is achieved through the regulation of distributed capacitance, and finally an effective combination of multiple resonant modes is achieved, thereby achieving broadband coverage of the target frequency band.

[0011] 2. The present invention provides a multi-mode resonant MNZ ring Wi-Fi antenna for a tablet computer. In order to ensure the continuity of the metal frame of the tablet computer, the antenna is designed in the rear camera area. In order to further improve the antenna bandwidth, a semi-ring microstrip antenna is introduced inside the MNZ segmented ring antenna without occupying other redundant space. The structure provides a resonant mode at a low frequency of 2.4 GHz, successfully covering a bandwidth of 2.4-2.5 GHz, and introduces two new resonance points in the high frequency part, further expanding the high frequency bandwidth.

[0012] 3. The multi-mode resonant MNZ ring Wi-Fi antenna provided by the present invention for use in a tablet computer may include the 2.4GHz (2.4-2.484GHz), 5GHz (5.13-5.83GHz) frequency bands within the Wi-Fi 6 protocol standard and the 6GHz (5.925-7.125GHz) within the Wi-Fi 6E protocol standard, but is not limited to these frequency bands. The design technology can be applied to other frequency bands.

[0013] 4. The present invention provides a multi-mode resonant MNZ ring Wi-Fi antenna for a tablet computer. An MNZ ring antenna and an antenna with a semi-ring microstrip parasitic structure are designed in the new space of the rear camera area of ​​the tablet computer. On the one hand, the antenna is located in the rear camera part of the tablet computer, which well ensures the continuity of the metal frame of the tablet computer. On the other hand, seven modes are introduced at high frequency and one resonant mode is introduced at low frequency to achieve full coverage of the frequency band within the Wi-Fi6 / 6E protocol. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

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

[0016] Figure 1b It is a top view of the present invention.

[0017] Figure 1c It is a schematic diagram of the second substrate structure of the present invention.

[0018] Figure 1d It is a side view of the present invention.

[0019] Figure 2 |S11| and gain simulation results of the antenna unit of the present invention.

[0020] Figures 3a to 3d These are the two-dimensional simulated radiation patterns of the antenna unit at 2.45 GHz, 5 GHz, 6 GHz and 7 GHz respectively.

[0021] Description of reference numerals:

[0022] 1. Metal frame; 2. Metal column; 3. First substrate; 4. Metallized through hole; 5. Second substrate; 6. Metal ground; 7. Coaxial feeding structure; 8. MNZ segmented loop antenna; 9. Semi-loop microstrip antenna. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0024] Embodiment 1:

[0025] This embodiment provides a multi-mode resonant MNZ ring Wi-Fi antenna for a tablet computer. The structural diagram is shown in FIG. Figures 1a to 1d As shown. The antenna structure includes: a metal frame 1, a metal column 2, an antenna substrate, and an MNZ segmented loop antenna 8 and a semi-ring microstrip antenna 9 located on the antenna substrate, wherein the overall antenna substrate is composed of a first substrate 3 and a second substrate 5 of different sizes, and the first substrate 3 is located on the top of the second substrate 5, so the lateral middle part of the antenna substrate is raised. In addition, there is a metallized through hole 4 connecting the segmented loop antenna 8 and the large metal ground 6, and a coaxial feeding structure 7 is arranged on the lower surface of the antenna substrate. In addition, a large metal ground 6 is also arranged on the lower surface of the antenna substrate. The present invention can have the advantages of easy frequency control while achieving broadband characteristics, and is of great practical value.

[0026] The RF excitation signal of the invention is fed from the bottom, and the annular segmented antenna structure 8 located thereon is fed through the coaxial feeding structure 7. The structure arranges an F4-B antenna substrate, and places the MNZ segmented loop antenna 8 on the antenna substrate as the main patch, generating five resonance points, and by adjusting the gap between the MNZ segmented loop antenna 8 to control the magnetic permeability of the antenna, the distance between each resonance point is compressed to achieve broadband coverage. In order to further cover the bandwidth coverage of the antenna low frequency band (2.4GHz), the structure introduces a group of semi-annular microstrip antennas 9. The parasitic structure generates a resonance mode covering 2.4-2.484GHz in the low frequency band through magnetic coupling, and adds two resonance points in the high frequency band to further broaden the high frequency bandwidth. It is worth noting that in order to simulate the internal environment of the tablet computer, the entire antenna structure uses a large metal ground 6 and there is a metal frame 1 surrounding the radiation structure. Since the size of the metal frame 1 has little effect on the antenna performance, a frame similar to the size of the substrate is used to simulate the internal environment of the tablet. In addition, two metal columns 2 are introduced to simulate the influence of the metal camera on the antenna performance. Finally, the present invention successfully implements the 2.4GHz (2.4-2.484GHz), 5GHz (5.13-5.83GHz) frequency bands within the Wi-Fi 6 protocol standard and the 6GHz (5.925-7.125GHz) frequency band within the Wi-Fi 6E protocol standard.

[0027] The MNZ segmented ring microstrip antenna designed by the present invention adopts a method of approximately adjusting the magnetic permeability of the MNZ antenna by loading capacitance, and uses the change of magnetic permeability to control the mode wavelength, and finally makes multiple resonant modes reasonably coupled under the same physical size to realize a multi-mode resonant MNZ ring antenna with broadband characteristics. Since the internal structure of a real tablet computer is extremely complex, and the structures of different types of computers are quite different, it is difficult to directly establish a model. In order to simplify the analysis, we only retain the structures that have the greatest impact on the performance of the antenna, namely the metal motherboard and the metal frame around the antenna, and create the model environment required for antenna design. This design first arranges a layer of F4-B antenna substrate, and then places a group of MNZ segmented ring antennas 8 and a group of semi-ring microstrip antennas 9 on top of it, where the MNZ segmented ring antenna 8 is the main radiation structure and the semi-ring microstrip antenna 9 is a parasitic radiation structure. The MNZ segmented loop antenna 8 provides five modes including the 0th order mode to cover the high frequency 5GHz-7 GHz target frequency band, and the parasitic semi-ring microstrip antenna 9 introduced inside the MNZ segmented loop antenna 8 as a parasitic radiation structure generates three resonant modes, of which mode 1 is located at 2.4GHz to cover 2.4-2.484GHz, and modes 2 and 3 are located near 7GHz to further expand the Wi-Fi6E frequency band. Finally, the present invention achieves full coverage of the three frequency bands in the Wi-Fi6 and Wi-Fi6E protocols.

[0028] This antenna design mainly solves the problem that the existing Wi-Fi antenna design applied to tablet computers cannot ensure the continuity of the metal frame and the bandwidth coverage of the designed antenna is limited. First, the present invention sets an F4-B substrate in free space, and designs a group of structural forms using MNZ segmented loop antennas on the substrate. The gap between each microstrip line is used as a distributed capacitor to adjust the magnetic permeability of the antenna; the MNZ segmented loop antenna provides a total of 5 resonant modes in the frequency band, which are the 0th, 1st, 2nd, 3rd, and 4th order modes of the MNZ antenna. The magnetic permeability of the antenna can be adjusted by adjusting the gap width between each microstrip line, thereby compressing the distance between the modes so that different modes can be combined with each other to form a broadband. Subsequently, a large metal ground 6 and a metal frame 1 are introduced to surround the antenna. At this time, due to the introduction of the ground, the bandwidth of the antenna is greatly enhanced. This is because although the excitation current of the antenna is very small, the radiation aperture becomes larger after the ground is introduced, which leads to a decrease in the quality factor of the proposed antenna. Secondly, the metal frame represents two metal segments parallel to the sides of the proposed antenna, effectively acting as a parallel capacitor, which improves impedance matching. In summary, the metal shell increases the radiation aperture and reduces the quality factor. The metal frame 1 acts as a parallel capacitor, which significantly improves the impedance performance. The final MNZ loop antenna covers the bandwidth of 4.8-7.12GHz in the target frequency band. Finally, in order to cover the bandwidth of the 2.4GHz band in the Wi-Fi 6 protocol, a semi-ring microstrip parasitic structure is introduced. This structure provides a resonant mode near 2.4GHz covering 2.4-2.484GHz, and adds two new resonant modes at 7GHz, which further improves the bandwidth of the antenna in the high frequency band while achieving the bandwidth in the low frequency band.

[0029] The present invention is designed for Wi-Fi 6 / 6E applications in all-metal shell tablets, and the antenna is located in the rear camera area of ​​the tablet to ensure the continuity of the tablet's metal frame. In addition, unlike the previous MNZ segmented loop antenna that only uses the 0th order mode of the antenna, in the present invention, the higher-order 1 / 2 / 3 / 4 modes are also successfully utilized. By regulating the distributed capacitance in the antenna to control the effective magnetic permeability of the antenna, the electrical length of the 0th / 1 / 2 / 3rd mode is reasonably lengthened, which allows multi-mode collaboration to be achieved in a group of MNZ segmented loop antennas 8 located in a full-metal shell tablet, and ultimately achieves broadband coverage. The invention introduces a group of MNZ segmented loop antennas 8 on the substrate. The antenna introduces a total of five resonance points to achieve coverage of the target frequency band, and controls the effective magnetic permeability of the antenna by adjusting the distributed capacitance in the antenna to achieve multi-mode synergy. Finally, the five resonance modes successfully cover the 5GHz (5.13-5.83GHz) frequency band in Wi-Fi 6 and the 6GHz (5.925-7.125GHz) frequency band extended by Wi-Fi 6E. In addition, in order to further achieve coverage of the 2.4GHz (2.4-2.484GHz) frequency band in Wi-Fi 6, a group of semi-ring microstrip antennas 9 are introduced on the substrate. On the one hand, this parasitic structure provides a resonance mode at the low frequency of 2.4GHz, successfully covering the bandwidth of 2.4-2.5GHz, and introduces two new resonance points in the high frequency part, further expanding the high frequency bandwidth.

[0030] The present invention proposes a multi-mode resonant MNZ ring Wi-Fi antenna for use in the rear camera area of ​​a full-metal shell tablet computer. The antenna is located between two metal cameras, making good use of the undeveloped area of ​​the mobile phone rear camera. The antenna radiator consists of a group of segmented ring microstrip structures and a semi-ring microstrip parasitic structure placed on a dielectric substrate, wherein the segmented ring microstrip structure is an MNZ segmented ring antenna 8. There is a large metal ground 6 at the bottom of the substrate to simulate the metal shell of the tablet computer. The invention aims to design a device that can cover the 2.4GHz (2.4-2.484GHz) and 5GHz (5.13-5.83GHz) frequency bands within the Wi-Fi 6 protocol and the 6GHz (5.925-7.125GHz) frequency band extended within the Wi-Fi 6E protocol, wherein the high-frequency part is mainly provided with bandwidth coverage by the MNZ segmented ring antenna 8, and the low-frequency part is mainly provided with bandwidth coverage by the parasitic semi-ring microstrip antenna 9. For the MNZ segmented loop antenna 8, it can approximately adjust the effective magnetic permeability of the antenna by loading capacitance, so that the multiple modes of the MNZ segmented loop antenna 8 are reasonably coupled under the same physical size to achieve the 5GHz (5.13-5.83GHz) frequency band within the Wi-Fi 6 protocol and the 6GHz (5.925-7.125GHz) frequency band coverage extended within the Wi-Fi 6E protocol. The parasitic semi-ring microstrip antenna 9 can provide 2.4GHz (2.4-2.484GHz) frequency band coverage within the Wi-Fi 6 protocol, and can further improve the bandwidth of the antenna in the high-frequency part. Finally, the present invention couples the MNZ segmented loop antenna 8 and the semi-ring microstrip antenna 9 to achieve full-band coverage of Wi-Fi 6 / 6E. Therefore, the present invention is an effective solution for realizing a Wi-Fi antenna with miniaturization advantages and broadband coverage.

[0031] Embodiment 2:

[0032] The dielectric constant of the dielectric substrate used in the antenna substrate of this embodiment is 4.4, and the loss tangent is 0.004; the overall section height is 2mm (~0.04λ 0 ~λ 0 @6GHz); the unit plane size is (30mm×12mm)+(17mm×12mm)(0.6λ 0 ×0.24λ 0 ~λ 0 @6GHz)+(0.34λ 0 ×0.24λ 0 ~λ 0 @6GHz). The simulation software uses HFSS, and the reflection coefficient and gain of the antenna unit are as follows Figure 2 As shown, |S 11|≤-6dB is the standard, and the impedance bandwidth range is 2.4-2.5GHz and 4.8-7.8GHz, achieving full coverage of the frequency bands within the Wi-Fi6 / 6E protocol. Figure 3 is a two-dimensional simulation radiation pattern of the antenna unit. Among them, (a) is the simulation radiation pattern at 2.45GHz, (b) is the simulation radiation pattern at 5GHz, (c) is the simulation radiation pattern at 6GHz, and (d) is the simulation radiation pattern at 7GHz; it can be seen that this antenna exhibits good radiation performance in all frequency bands. This embodiment implements a design scheme of a group of MNZ ring antennas 8 in conjunction with a semi-ring microstrip antenna 9, which has a compact structure and a small planar size of the radiation unit. The size of the radiation unit is (30mm×12mm×2mm)+(17mm×12mm×2mm)(0.6λ 0 ×0.24λ 0 ×0.04λ 0 )+(0.34λ 0 ×0.24λ 0 ×0.04λ 0 ). Under this structure, the proposed antenna design has the advantages of simple structure, wide coverage bandwidth, and easy and flexible adjustment of each frequency point.

[0033] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A multi-mode resonant MNZ ring Wi-Fi antenna for tablet computers, characterized in that: It comprises a metal frame (1), an antenna substrate and a metal ground (6) which are arranged in sequence from top to bottom; an MNZ segmented loop antenna (8) and a semi-loop microstrip antenna (9) are arranged on the antenna substrate, and a coaxial feeding structure (7) is arranged on the lower surface of the antenna substrate.

2. The multi-mode resonant MNZ ring Wi-Fi antenna for tablet computers according to claim 1, characterized in that: The MNZ segmented loop antenna (4) is connected to the metal ground (8) via a metallized through hole (4).

3. The multi-mode resonant MNZ ring Wi-Fi antenna for tablet computers according to claim 2, characterized in that: The antenna substrate is composed of a first substrate (3) and a second substrate (5) of different sizes.

4. The multi-mode resonant MNZ ring Wi-Fi antenna for tablet computers according to claim 3, characterized in that: A metal column (2) is arranged on the antenna substrate, and the metal column (2) passes through the antenna substrate and the metal ground (6).

5. The multi-mode resonant MNZ ring Wi-Fi antenna for tablet computers according to claim 4, characterized in that: The MNZ segmented loop antenna (4) arranged on the antenna substrate serves as a main patch.

6. The multi-mode resonant MNZ ring Wi-Fi antenna for tablet computers according to claim 5, characterized in that: The semi-annular microstrip antenna (5) generates a resonance mode covering 2.4-2.484 GHz in the low frequency band through magnetic coupling, and adds two resonance points in the high frequency band.

7. The multi-mode resonant MNZ ring Wi-Fi antenna for tablet computers according to claim 6, characterized in that: The first substrate (3) is smaller than the second substrate (5) and is located on the upper surface of the second substrate (5); the first substrate (3) is located in the middle area of ​​the second substrate (5) in the width direction.

8. The multi-mode resonant MNZ ring Wi-Fi antenna for tablet computers according to claim 7, characterized in that: An MNZ segmented loop antenna (8) and a semi-ring microstrip antenna (9) are arranged on the upper surface of the first substrate (3) and between the first substrate (3) and the second substrate (5); the MNZ segmented loop antenna (8) and the semi-ring microstrip antenna (9) on the upper surface of the first substrate (3) are extended to the side surface of the first substrate (3) and are further connected to the MNZ segmented loop antenna (8) and the semi-ring microstrip antenna (9) between the first substrate (3) and the second substrate (5).

9. The multi-mode resonant MNZ ring Wi-Fi antenna for tablet computers according to claim 8, characterized in that: The metal ground (8) is larger than the antenna substrate and the metal frame (1).

10. The multi-mode resonant MNZ ring Wi-Fi antenna for tablet computers according to claim 9, characterized in that: The coaxial feeding structure (7) passes through the second substrate (5) upwards.

Images