Broadband filtering antenna suitable for smart home

Abstract

The invention discloses a multi-band compatible filtering patch antenna suitable for smart home. The multi-band compatible filtering patch antenna comprises a first-layer radiation patch, a second-layer dielectric substrate and a third-layer metal grounding plate. Wherein the radiation patches comprise a central driving patch, an arc patch and a transverse microstrip patch, the three patches respectively control a working mode in an antenna frequency band, and realize surface current cancellation at a specific frequency through interaction, so that obvious radiation zero points at a high position and a low position are realized on the premise of not introducing an additional filtering structure. Besides, the antenna is optimized and improved according to the requirements of an intelligent home system, the transmission band is designed to be 5-7GHz, and sub-6G, Wi-Fi 6E and Wi-Fi 7 are effectively covered, so that the antenna can be widely applied to various intelligent home communication systems such as illumination control, security monitoring, household appliance control and environmental perception, and the application range is wide. And a new solution is provided for performance improvement and application expansion of the intelligent home terminal control system.

Description

Technical Field

[0001] The present invention belongs to the technical field of antennas for wireless communication terminals and relates to a wide-band filtering antenna suitable for smart homes. Background Art

[0002] In recent years, with the rapid development of the Internet of Things and smart home industries, various smart devices have been used more and more widely in homes, involving lighting control, security monitoring, home appliance control, environmental perception and other aspects. These smart devices usually rely on wireless communications to achieve interconnection and remote control. Due to the large number and variety of smart devices in the home environment, higher requirements are placed on communication devices in terms of frequency band compatibility and signal transmission stability.

[0003] Traditional antenna designs are often limited to a single frequency band and are difficult to adapt to the needs of different types of smart devices. However, wideband filtering antennas can effectively cover sub-6G, Wi-Fi 6E and Wi-Fi 7 due to their wider bandwidth, and can effectively suppress out-of-band interference signals to ensure communication quality, making them gradually gain attention and application in smart home wireless communication terminals.

[0004] The frequency band requirements of devices in smart home systems usually involve multiple frequency bands, and filtering antennas with wide frequency bands have significant advantages in smart home applications. First, by achieving compatibility of one antenna to support multiple frequency bands, the access requirements of different types of devices can be met. For example, when a router or wireless gateway supports multiple smart home devices at the same time, the antenna that matches it needs to cover frequency bands such as 5GHz to 7GHz to adapt to the working frequencies of various types of devices and ensure stable data transmission. Secondly, wide-band antennas can be flexibly switched between different frequency bands to provide seamless transition for communication between devices working in different frequency bands. In this way, even in a home network with dense devices, the network load can be evenly distributed, the frequency band congestion problem can be reduced, and the communication efficiency can be improved. In addition, wide-band antennas can also reduce the number of antennas in terminal devices, reduce the size and power consumption of the device, and improve the overall communication performance and user experience. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a wide-band filtering antenna suitable for smart homes.

[0006] The present invention comprises a radiation patch at the top, a dielectric substrate in the middle and a metal ground plate at the bottom. A coaxial feeding structure is arranged on the central axis of the antenna, and a bottom-fed coaxial feeding method is adopted for feeding. The radiation patch layer comprises a central driving patch, arc patches located on both sides of the central driving patch and a transverse microstrip patch connecting the central driving patch and the arc patches.

[0007] Furthermore, the central driving patch is obtained by cutting the bottom part of a circular patch and adding a rectangular patch on the top, so as to improve the capacitance effect of the circular patch and offset the inductance effect introduced by the biased coaxial feeding.

[0008] Furthermore, the center of the circular patch deviates from the center of the substrate.

[0009] Furthermore, the arc-shaped patch is obtained by cutting the same upper and lower parts of a ring-shaped patch with the center of the substrate as the center of the circle.

[0010] Furthermore, the transverse microstrip patch is located at the center of the substrate.

[0011] Furthermore, the dielectric substrate is made of FR-4 dielectric board with a dielectric constant of 4.3, and the central driving patch, arc patch, lateral microstrip patch and metal ground plate are all made of metal copper.

[0012] Furthermore, the coaxial feeding structure is located on the axis of the substrate, deviating from the center of the substrate.

[0013] Furthermore, the central resonant frequency of the antenna passband is adjusted by changing the radius of the central drive patch.

[0014] Furthermore, the high-frequency resonance frequency of the antenna passband is adjusted by changing the length of the arc-shaped patch.

[0015] Furthermore, the low-frequency resonant frequency of the antenna passband is adjusted by changing the width of the transverse microstrip patch.

[0016] Compared with the prior art, the present invention has the following significant advantages: 1. The present invention adopts a single-layer dielectric plate, which has a simple structure and is easy to process.

[0017] 2. The present invention utilizes the current cancellation characteristic (the surface currents generated on the arc-shaped patches on both sides are of the same magnitude and opposite direction, forming a radiation zero point) for filtering, does not rely on other parasitic filtering structures, has a simple design structure, and reduces the design complexity.

[0018] 3. The effective radiation frequency band of the present invention covers 5GHz-7Ghz, which meets the working requirements of most smart home devices on the market.

[0019] 4. The three patches of the present invention each correspond to a working mode within the antenna frequency band and can be controlled relatively independently, thus having greater design flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of an embodiment of the present application; Figure 2 is a front plan view of an embodiment of the present application; Figure 3 It is a comparison diagram of the simulation and actual measurement of the S parameters of the embodiment of the present application; Figure 4 is a comparison diagram of the simulation and actual measurement of the gain curve of the embodiment of the present application; Figure 5 It is a comparison diagram of the simulation and actual measurement of the total efficiency curve of the embodiment of the present application; Figure 6 It is a comparison diagram between simulation and actual measurement of the plane main polarization and cross polarization directions at the first resonant frequency (4.86 GHz) of the embodiment of the present application; Figure 7 It is a comparison diagram between simulation and actual measurement of the plane main polarization and cross polarization directions at the second resonant frequency (5.79 GHz) of the embodiment of the present application; Figure 8 It is a comparison diagram between simulation and actual measurement of the plane main polarization and cross-polarization directions at the third resonant frequency (6.72 GHz) of the embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] It should be noted that, in order to avoid obscuring the present invention due to some unimportant details, only structures and / or processing steps closely related to the scheme of the present invention are shown in the drawings, and other details that are not closely related to the present invention are omitted.

[0023] The embodiment of the present application provides a specific embodiment of a wide-band filtering antenna suitable for smart homes. The antenna adopts a single-layer dielectric plate structure, can selectively utilize signal energy in the range of 5GHz-7GHz, and has a high roll-off coefficient.

[0024] like Figure 1 As shown, this embodiment is composed of a three-layer structure, wherein the first layer is composed of a central driving patch, an arc patch and a transverse microstrip patch, the second layer is a dielectric substrate, and the third layer is a metal ground plate, and a bottom-fed coaxial feeding method is used for feeding.

[0025] This embodiment uses a single-layer FR-4 substrate with a thickness of 3 mm and a length and width of 30.0 mm*28.0 mm, and the overall structure includes: a central driving patch 1, an arc patch 2, a transverse microstrip patch 3, a dielectric substrate 4, a metal ground plate 5, and a coaxial feeding structure 6. The central driving patch 1, the arc patch 2, and the transverse microstrip patch 3 are printed on the top layer of the dielectric substrate 4, and the metal ground plate 5 is printed on the bottom layer of the dielectric substrate 8.

[0026] like Figure 2As shown, in a preferred example, the center of the antenna center is O1, the center of the circular part of the central driving patch 1 is O2, located 0.6mm in the negative direction of the y-axis of O1, and the radius r1=6.8mm; the bottom is cut along the positive direction of the y-axis with a depth of d3=1.6mm; the top rectangular patch has a length of l3=2.5mm, and exceeds the circular part by a distance d2=1mm; the arc patch 2 takes O1 as the center, with an inner diameter r2=9.8mm, an outer diameter r3=13.8mm, and a longitudinal length l2=9.7mm; the transverse microstrip patch 3 takes O1 as the center, connects the central driving patch 1 and the arc patch 2, and has a width w2=5.0mm; the coaxial feeding structure 6 is located at a distance d1=4mm in the positive direction of the y-axis of O1, and the dielectric substrate adopts a FR-4 dielectric board with a dielectric constant of 4.3, and the central driving patch 1, the arc patch 2, the transverse microstrip patch 3 and the metal ground plate 5 are all made of metal copper.

[0027] As an improvement of the present application, the central resonant frequency of the antenna passband can be adjusted when the radius of the central drive patch is changed.

[0028] As an improvement of the present application, the high-frequency resonance frequency of the antenna passband can be adjusted when the length of the arc-shaped patch is changed.

[0029] As an improvement of the present invention, the low-frequency resonance frequency of the antenna passband can be adjusted when the width of the lateral microstrip patch is changed.

[0030] like Figure 3 As shown in the figure, it is a comparison chart of the simulation and actual measurement of the S parameters of the filter antenna of the embodiment of the present application. The actual working bandwidth of the antenna below -10dB is 4.66GHz-7.14GHz, which is slightly offset to the low frequency within the normal range compared with the simulation result. The fractional bandwidth reaches 42%, covering sub-6G, Wi-Fi 6E and Wi-Fi 7 frequency bands.

[0031] like Figure 4 As shown in the figure, it is a comparison diagram of the line simulation and actual measurement of the gain curve of the filtering antenna in the embodiment of the present application. The actual peak gain is 6.0dBi and the average gain is 4.76dBi. The gain flatness in the passband is less than 1.5dBi, which is suitable for most smart home device usage scenarios. In addition, the gain curve also shows a steep roll-off coefficient, with the roll-off coefficients on the left and right sides being α1 = 1.30 and α2 = 3.82 (α>1 is considered a steep roll-off), which improves the stability of communication.

[0032] like Figure 5As shown, there is a comparison diagram between the simulation and the actual measurement of the total efficiency curve of the filtering antenna in the embodiment of the present application. The measured total radiation efficiency is slightly lower than the simulated efficiency of 82%, which may be caused by the uncertainty of the material, manufacturing or test environment. In general, the measurement results are consistent with the simulation results, which verifies the practical feasibility of the antenna design.

[0033] like Figure 6 , 7 8 are simulation and measured comparison diagrams of the main polarization and cross-polarization directions of the xoz plane and yoz plane at three resonant frequencies (4.86GHz, 5.79GHz, and 6.72GHz) of the embodiment of the present application. The results of the main polarization direction show that the measured and simulated directions are highly consistent, and the energy is effectively concentrated in the main radiation direction, indicating the side-radiation characteristics of the antenna. The cross-polarization results show good polarization isolation, and the minimum difference observed in all results is greater than 20dB, which can effectively reduce signal interference and improve the overall communication quality.

[0034] In summary, this application uses a simple structure to realize a wideband filtering antenna with two obvious high and low radiation zero points without introducing additional filtering structures, and optimizes and improves it according to the needs of smart home systems, designing the passband at 5GHz-7GHz, effectively covering sub-6G, Wi-Fi 6E and Wi-Fi 7. As a key component of the RF front end of a highly integrated wireless transceiver, the antenna can be widely used in a variety of smart home communication systems such as lighting control, security monitoring, home appliance control, and environmental perception, providing a new solution for performance improvement and application expansion of smart home terminal control systems.

[0035] The above is only a preferred embodiment of the present invention, but the implementation of the present invention is not limited to the above embodiment. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principle of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A wide-band filtering antenna suitable for smart home, comprising a radiation patch at the top, a dielectric substrate (4) in the middle and a metal ground plate (5) at the bottom, a coaxial feeding structure (6) is provided on the central axis of the antenna, and a bottom-fed coaxial feeding method is adopted for feeding, characterized in that: The radiation patch layer comprises a central driving patch (1), arc patches (2) located on both sides of the central driving patch (1), and a transverse microstrip patch (3) connecting the central driving patch (1) and the arc patches (2).

2. A wide-band filtering antenna suitable for smart home according to claim 1, characterized in that: The central driving patch (1) is obtained by cutting the bottom part of a circular patch and adding a rectangular patch on the top, and is used to improve the capacitance effect of the circular patch and offset the inductance effect introduced by the biased coaxial feeding.

3. A wide-band filtering antenna suitable for smart home according to claim 2, characterized in that: The center of the circular patch deviates from the center of the substrate.

4. A wide-band filtering antenna suitable for smart home according to claim 2 or 3, characterized in that: The arc-shaped patch (2) is obtained by cutting the same upper and lower parts of a ring-shaped patch with the center of the substrate as the center of the circle.

5. The wide-band filtering antenna suitable for smart home according to claim 1, characterized in that: The transverse microstrip patch (3) is located at the center of the substrate.

6. The wide-band filtering antenna suitable for smart home according to claim 1, characterized in that: The dielectric substrate (4) is a FR-4 dielectric board with a dielectric constant of 4.3, and the central drive patch (1), the arc patch (2), the transverse microstrip patch (3) and the metal ground plate (5) are all made of metal copper.

7. The wide-band filtering antenna suitable for smart home according to claim 1, characterized in that: The coaxial feeding structure (6) is located on the axis of the substrate, offset from the center of the substrate.

8. A wide-band filtering antenna suitable for smart home according to claim 1 or 2, characterized in that: The central resonant frequency of the antenna passband is adjusted by changing the radius of the central driving patch (1).

9. The wide-band filtering antenna suitable for smart home according to claim 4, characterized in that: The high-frequency resonance frequency of the antenna passband is adjusted by changing the length of the arc-shaped patch (2).

10. The wide-band filtering antenna suitable for smart home according to claim 5, characterized in that: The low-frequency resonance frequency of the antenna passband is adjusted by changing the width of the transverse microstrip patch (3).

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