Low-profile broadband antenna for 5G-WiFi frequency band

Abstract

The invention discloses a low profile broadband antenna for a 5G-WiFi frequency band. Comprising a dielectric substrate and a metal radiation layer arranged on the upper surface of the dielectric substrate; the metal radiation layer comprises a rectangular patch and two identical U-shaped patches, and the two identical U-shaped metal patches are close to the radiation edge and the non-radiation edge of the rectangular patch at the same time and surround the rectangular patch. Wherein two longitudinal metal slots and one transverse rectangular slot are loaded on the rectangular patch to enhance the bandwidth of the antenna. According to the antenna provided by the invention, the antenna can be ensured to have a relatively low antenna profile, and meanwhile, the antenna has enough bandwidth to cover a WLAN (Wireless Local Area Network) 5.2 GHz (5.15 to 5.36 GHz), a WLAN 5.8 GHz (5.725 to 5.825 GHz) and a WiMAX (Worldwide Interoperability for Microwave Access) 5.5 (5.25 to 5.825 GHz).

Description

Technical Field

[0001] The present invention belongs to the technical field of microstrip antennas, and in particular relates to a low-profile broadband antenna for the 5G-WiFi frequency band. Background Art

[0002] 5G-WiFi (i.e., 802.11ac and 802.11ax standards) operates on the 5 GHz band, providing higher data transmission rates and better network performance. The 5 GHz band has a wider available bandwidth and can support multiple non-overlapping channels, thereby reducing interference and increasing network capacity. With the popularity of applications such as smart homes, the Internet of Things (IoT), high-definition video streaming, and virtual reality (VR), the demand for antennas for the 5G Wi-Fi band is increasing.

[0003] Broadband antennas can provide good performance over a wide frequency range, which is particularly important for 5G Wi-Fi. The available bandwidth of the 5G-WiFi band is wide, from 5.150 GHz to 5.850 GHz, covering multiple sub-bands, such as WLAN5.2GHz (5.15-5.36GHz), WLAN5.8GHz (5.725-5.825GHz), WiMAX5.5 (5.25-5.825GHz) and other frequency bands. Broadband antennas can cover all frequency bands within this range, providing greater flexibility and compatibility. Traditional microstrip antennas are favored by antenna researchers because of their small size, low profile, low price, and easy integration. However, due to their low profile and small size, narrow bandwidth has become an inherent disadvantage. How to design a broadband antenna that meets the design requirements while maintaining the advantages of the low profile of the microstrip antenna has become a research problem. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and propose a low-profile broadband antenna for the 5G-WiFi frequency band, which ensures a low antenna profile while ensuring that the antenna has sufficient bandwidth to cover the WLAN 5.2 GHz (5.15-5.36 GHz), WLAN 5.8 GHz (5.725-5.825 GHz) and WiMAX 5.5 (5.25-5.825 GHz) frequency bands.

[0005] The present invention is achieved through the following technical solutions: A low-profile broadband antenna for the 5G-WiFi frequency band comprises a dielectric substrate and a metal radiation layer arranged on the upper surface of the dielectric substrate; the metal radiation layer comprises a rectangular patch and two identical U-shaped patches, wherein the rectangular patch is placed at the center of the dielectric substrate, and the two U-shaped patches are symmetrically arranged on both sides of the rectangular patch and are adjacent to the radiation side and non-radiation side of the rectangular patch at the same time, surrounding the rectangular patch; two longitudinal rectangular slots and one transverse rectangular slot are loaded on the rectangular patch to enhance the antenna bandwidth, wherein the transverse rectangular slot is placed at the center of the rectangular patch, and the two longitudinal rectangular slots are centrally symmetrically distributed about the center point of the rectangular patch, and the outer ends extend to the side edges of the rectangular patch respectively.

[0006] Furthermore, the dielectric substrate is FR4, whose relative dielectric constant, loss tangent, length and width are all 35 mm, and thickness is 1.585 mm.

[0007] Furthermore, the metal radiation patch on the upper surface of the dielectric substrate, namely the central rectangular patch loaded with two longitudinal rectangular gaps, one transverse rectangular gap and two identical U-shaped patches, are all copper-clad, and the thickness is 0.035 mm.

[0008] The length of the rectangular patch is L = 16.5mm, and the width is W = 11.8mm. Two identical longitudinal rectangular slits are loaded on the rectangular patch, with a length of 5.46mm, a width of 0.12mm, and a distance of 2.70mm from the center axis of the antenna. A transverse rectangular slit is loaded on the rectangular patch, with a length of 2.73mm, a width of 0.25mm, and the midpoint of its diagonal coincides with the center of the antenna.

[0009] Furthermore, the U-shaped patch is composed of a long rectangle and two identical short rectangles, wherein the long rectangle is 33 mm long and 7 mm wide; the short rectangle is 6.6 mm long and 6.3 mm wide; and the distance between the short rectangle and the outer edge of the long rectangle is 0.5 mm.

[0010] Furthermore, a coaxial feeding method is adopted, the radius of the coaxial inner core is 0.3 mm, and the radius of the outer core is 1.29 mm; the feeding position is located 5 mm directly below the symmetry center of the antenna.

[0011] The beneficial effects of the present invention are as follows: the present invention designs a low-profile broadband antenna for the 5G-WiFi frequency band based on the microstrip antenna theory. The central rectangular patch provides a low-frequency resonance point, and the two U-shaped patches provide a high-frequency resonance point. By adjusting the coupling gap between the U-shaped patch and the rectangular patch, two longitudinal rectangular gaps and one transverse rectangular gap are loaded on the central rectangular patch to adjust the spacing between the two resonance points and expand the bandwidth. This allows the antenna to have sufficient bandwidth to cover the WLAN5.2GHz (5.15-5.36GHz), WLAN5.8GHz (5.725-5.825GHz) and WiMAX5.5 (5.25-5.825GHz) frequency bands while ensuring a lower antenna profile. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Schematic diagram of a three-dimensional structure of an embodiment of the present invention.

[0013] Figure 2 It is a top view of an embodiment of the present invention.

[0014] Figure 3 This is step 1 of the embodiment of the present invention.

[0015] Figure 4 Graph showing the reflection coefficient S11 of step 1 of an embodiment of the present invention.

[0016] Figure 5 This is step 2 of the embodiment of the present invention.

[0017] Figure 6 This is a reflection coefficient S11 diagram of step 2 of an embodiment of the present invention.

[0018] Figure 7 Graph showing the reflection coefficient S11 of an embodiment of the present invention.

[0019] Figure 8 : is the radiation pattern of an embodiment of the present invention at 5.12 GHz.

[0020] Fig. 9 : is the radiation pattern of an embodiment of the present invention at 5.70 GHz. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is described in detail below in conjunction with the drawings in the technical specification, but the protection scope of the present invention is not limited to the following.

[0022] like Figure 1-2 As shown, a low-profile broadband antenna for the 5G-WiFi frequency band provided in an embodiment of the present invention comprises: a dielectric substrate (1) and a metal radiation layer (2) arranged on the dielectric substrate.

[0023] The metal radiation layer comprises a rectangular patch (3) and two identical U-shaped patches (4).

[0024] The rectangular patch (3) is located at the exact center of the dielectric substrate (1), and is loaded with two longitudinal rectangular slits (5) and a transverse rectangular slit, the two rectangular slits being located respectively at the lower left and upper right of the exact center of the antenna and symmetrically distributed about the center of the antenna. The transverse rectangular slit is located at the center of the antenna, and the midpoint of its diagonal coincides with the center of the antenna.

[0025] The U-shaped patch (4) is composed of a long rectangle (7) and two identical short rectangles (8). The two identical U-shaped patches (4) are respectively located directly above and directly below the rectangular patch and are axially symmetrically distributed about the center of the antenna.

[0026] The low-profile broadband antenna for the 5G-WiFi frequency band adopts a coaxial feeding method. The coaxial feeding point is located 5 mm below the center of the antenna. The coaxial is directly welded on the rectangular patch (3), and the inductance of the coaxial is used to offset the capacitive characteristics generated by the two rectangular gaps on the rectangular patch.

[0027] The design idea of ​​the embodiment of the present invention is: the rectangular patch (3) at the center of the antenna provides a low-frequency resonance point, and the two U-shaped patches (4) provide a high-frequency resonance point. At the same time, the coupling gap between the rectangular patch (3) and the U-shaped patch (4) is adjusted, and two longitudinal rectangular gaps (5) and one transverse rectangular gap (6) are loaded on the rectangular patch (3), so that the antenna bandwidth meets the design requirements and covers the 5G Wi-Fi frequency band. The technical effects of the present invention are described in detail below in conjunction with the accompanying drawings.

[0028] ]like Figure 3 As shown, in the first step of the embodiment of the present invention, a low-frequency resonance point is provided by the central rectangular patch (3). The present invention is aimed at the 5G-WiFi frequency band, and the low-frequency resonance point is expected to be set between 5.0GHz and 5.2GHz. According to the microstrip antenna theory, the length of the central rectangular patch is L=16.5mm and the width is W=11.8mm. The reflection coefficient S11 of step one is shown in FIG. Figure 4 shown.

[0029] like Figure 5As shown, step two of the embodiment of the present invention: two identical U-shaped patches (4) and a central rectangular patch (3) are coupled to generate a high-frequency resonance point. After design and debugging, the coupling patch part is finally designed to be U-shaped, consisting of a long rectangle and two identical short rectangles. The long rectangle is 33mm long and 7mm wide; the short rectangle (8) is 6.6mm long and 6.3mm wide. The distance between the short rectangle (8) and the outer edge of the long rectangle is 0.5mm. The coupling width of the U-shaped patch (4) and the central rectangular patch (3) in the up and down directions is 1.3mm, and the coupling width in the left and right directions is 1.1.mm. The reflection coefficient S11 of step two is shown in the figure Figure 6 shown.

[0030] like Figure 2 As shown, step three of the embodiment of the present invention is to load two longitudinal rectangular slots (5) and one transverse rectangular slot (6) on the central rectangular patch (3), adjust the distance between the two resonance points, and enhance the bandwidth so that the antenna bandwidth can meet the design requirements and cover the 5G-WiFi frequency band. At this point, the design of the embodiment of the present invention is completed. The final reflection coefficient S11 of the embodiment of the present invention is shown in FIG. Figure 8 As shown, it can be seen that the reflection coefficients of the low-frequency resonance point at 5.12 GHz and the high-frequency resonance point at 5.70 GHz are both lower than -20, indicating a good match.

[0031] like Figure 8-9 As shown, the radiation patterns of the low-profile broadband antenna for the 5G-WiFi frequency band provided by the embodiment of the present invention respectively operate at 5.12 GHz and 5.70 GHz. It can be seen that the antenna pattern is stable, the difference between the main polarization and the cross polarization is greater than 20 dB, and the performance is good.

[0032] In the embodiments of the present invention, the descriptions of "upper", "lower", "left", and "right" are only used to describe the present invention and simplify the description, and cannot be understood as indicating or implying that a device or component must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "longitudinal", "lateral", etc. are only used to describe the orientation, and cannot be understood as indicating or implying relative importance.

[0033] The above is a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not depart from the spirit and scope of the present invention, and should be within the scope of protection of the claims attached to the present invention.

Claims

1. A low-profile broadband antenna for the 5G-WiFi frequency band, characterized by: The antenna comprises a dielectric substrate (1) and a metal radiation patch (2) arranged on the upper surface of the dielectric substrate (1); the metal radiation layer (2) comprises a rectangular patch (3) and two identical U-shaped patches (4), wherein the rectangular patch (3) is arranged at the center of the dielectric substrate (1), and the two U-shaped patches (4) are symmetrically arranged on both sides of the rectangular patch (3) and are adjacent to the radiation side and the non-radiation side of the rectangular patch (3) to surround the rectangular patch (3); two longitudinal rectangular slots (5) and one transverse rectangular slot (6) are loaded on the rectangular patch (3) to enhance the antenna bandwidth, wherein the transverse rectangular slot (6) is arranged at the center of the rectangular patch (3), and the two longitudinal rectangular slots (5) are centrally symmetrically distributed about the center point of the rectangular patch (3), and the outer ends extend to the side edges of the rectangular patch (3) respectively.

2. A low-profile broadband antenna for the 5G-WiFi frequency band according to claim 1, characterized in that: The dielectric substrate (1) is FR4, whose relative dielectric constant, loss tangent, length and width are both 35 mm, and thickness is 1.585 mm.

3. A low-profile broadband antenna for 5G-WiFi frequency band according to claim 1, characterized in that: The metal radiation patch (2) located on the upper surface of the dielectric substrate (1), namely the central rectangular patch (3) loaded with two longitudinal rectangular gaps (5) and one transverse rectangular gap (6) and two identical U-shaped patches are all copper-clad, and the thickness is 0.035 mm.

4. The low-profile broadband antenna for the 5G-WiFi frequency band according to claim 1, characterized in that: The rectangular patch (3) has a length of L = 16.5 mm and a width of W = 11.8 mm.

5. The low-profile broadband antenna for the 5G-WiFi frequency band according to claim 1, characterized in that: Two identical longitudinal rectangular slits (5) are loaded on the rectangular patch (3), with a length of 5.46 mm, a width of 0.12 mm, and a distance of 2.70 mm from the central axis of the antenna.

6. The low-profile broadband antenna for the 5G-WiFi frequency band according to claim 1, characterized in that: A transverse rectangular gap (6) is loaded on the rectangular patch (3), the length of which is 2.73 mm, the width of which is 0.25 mm, and the midpoint of the diagonal of which coincides with the center of the antenna.

7. The low-profile broadband antenna for the 5G-WiFi frequency band according to claim 1, characterized in that: The U-shaped patch (4) is composed of a long rectangle (7) and two identical short rectangles (8), wherein the long rectangle is 33 mm long and 7 mm wide; the short rectangle (8) is 6.6 mm long and 6.3 mm wide; and the distance between the short rectangle (8) and the outer edge of the long rectangle is 0.5 mm.

8. The low-profile broadband antenna for the 5G-WiFi frequency band according to claim 1, characterized in that: Coaxial feeding is adopted, the radius of the coaxial inner core is 0.3mm, and the radius of the outer core is 1.29mm; the feeding position is 5mm directly below the symmetry center of the antenna.

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