Microstrip antenna and monitoring device

Abstract

The utility model provides a microstrip antenna and monitoring equipment. The microstrip antenna comprises an antenna radiator, a dielectric layer, a reference ground layer and a wiring layer which are sequentially stacked, the microstrip antenna further comprises a radar assembly, the radar assembly is arranged in the wiring layer and comprises at least two feed ports, and the antenna radiator is in signal connection with the feed ports. The at least two feed ports comprise at least one signal receiving feed port and at least one signal transmitting feed port, and the resonant dominant frequency of the microstrip antenna is greater than or equal to 5725 MHZ and less than or equal to 5850 MHZ. According to the utility model, the problem of high false alarm rate of monitoring equipment in the prior art is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of antenna equipment, in particular to a microstrip antenna and monitoring equipment. Background Art

[0002] With the increasing popularity of smart homes, the monitoring capabilities of smart home devices are becoming increasingly important, especially in scenarios such as pet monitoring, elderly care, and pedestrian detection inside and outside the home. While infrared detection technology, a widely adopted non-contact monitoring method in the early days, has met basic home monitoring needs to a certain extent, its limitations and flaws have gradually become apparent, particularly in terms of false alarm rates. These issues significantly impact the reliability of smart home monitoring, reduce user experience, and increase unnecessary alarm processing burdens.

[0003] That is to say, the monitoring equipment in the prior art has the problem of high false alarm rate. Utility Model Content

[0004] The main purpose of the utility model is to provide a microstrip antenna and a monitoring device to solve the problem of high false alarm rate in the monitoring device in the prior art.

[0005] To achieve the above-mentioned objectives, according to one aspect of the present invention, a microstrip antenna is provided, comprising an antenna radiator, a dielectric layer, a reference ground layer, and a routing layer stacked in sequence. The microstrip antenna also comprises a radar assembly, which is arranged in the routing layer. The radar assembly comprises at least two feed ports, and the antenna radiator is signal-connected to the feed ports. The at least two feed ports comprise at least one signal receiving feed port and at least one signal transmitting feed port. The resonant main frequency of the microstrip antenna is greater than or equal to 5725 MHz and less than or equal to 5850 MHz.

[0006] In some optional embodiments, the antenna radiator is conformally covered on a surface of the dielectric layer that is away from the reference ground layer.

[0007] In some optional embodiments, the area of ​​the antenna radiator is smaller than the area of ​​the surface of the dielectric layer in contact with the antenna radiator.

[0008] In some optional embodiments, the antenna radiator satisfies at least one of the following:

[0009] The antenna radiator is coaxial with the dielectric layer;

[0010] The antenna radiator is a centrally symmetrical figure;

[0011] At least one side of the antenna radiator is arranged at an angle to at least one side of the dielectric layer.

[0012] In some optional embodiments, the antenna radiator is square, and the length of the antenna radiator is greater than or equal to 6.2 mm and less than or equal to 10.2 mm.

[0013] In some optional embodiments,

[0014] The reference ground layer includes a first PCB board and a first metal plate, the first PCB board is connected to the surface of the dielectric layer away from the antenna radiator, and the thickness of the first PCB board is greater than or equal to 0.9 mm and less than or equal to 1.5 mm; the first metal plate is connected to the surface of the first PCB board away from the dielectric layer, and the first metal plate is the reference ground of the microstrip antenna; and / or the routing layer includes a second PCB board and a second metal plate, the second PCB board is connected to the surface of the reference ground layer away from the dielectric layer, and the thickness of the second PCB board is greater than or equal to 0.09 mm and less than or equal to 0.15 mm; the second metal plate is connected to the surface of the second PCB board away from the reference ground layer, the radar component is connected to the second metal plate, and the second metal plate has a feeding port.

[0015] In some optional embodiments, the microstrip antenna further includes at least two feeding connectors, and two ends of the feeding connectors are respectively connected to the feeding port and the antenna radiator.

[0016] In some optional embodiments, the orthographic projection of the dielectric layer on the routing layer and the orthographic projection of the reference ground layer on the routing layer completely overlap with the routing layer.

[0017] In some optional embodiments, the dielectric layer is rectangular and satisfies at least one of the following:

[0018] The length of the dielectric layer is greater than or equal to 33 mm and less than or equal to 53 mm;

[0019] The width of the dielectric layer is greater than or equal to 18 mm and less than or equal to 38 mm;

[0020] The thickness of the dielectric layer is greater than or equal to 0.09 mm and less than or equal to 0.15 mm.

[0021] According to another aspect of the present invention, a monitoring device is provided, comprising the above-mentioned microstrip antenna.

[0022] Applying the technical solution of the present utility model, the microstrip antenna includes an antenna radiator, a dielectric layer, a reference ground layer and a routing layer stacked in sequence. The microstrip antenna also includes a radar component, which is arranged in the routing layer. The radar component includes at least two feed ports, and the antenna radiator is signal-connected to the feed port. The at least two feed ports include at least one signal receiving feed port and at least one signal transmitting feed port. The resonant main frequency of the microstrip antenna is greater than or equal to 5725 MHZ and less than or equal to 5850 MHZ.

[0023] By setting at least two feed ports in the routing layer, the microstrip antenna of the present invention can simultaneously receive and transmit signals. At least one signal receiving feed port is responsible for receiving the echo signal, while at least one signal transmitting feed port is responsible for transmitting the initial signal. This dual-feed design overcomes the limitations of traditional single-feed antennas in radar functions and improves the overall performance and flexibility of the radar system. By integrating the radar component in the routing layer of the microstrip antenna, the present invention achieves close coupling between the antenna and the radar chip, reducing the complexity and cost of the traditional design of separating the antenna and radar component. This highly integrated design not only simplifies the assembly and debugging of the device, but also makes the antenna more compact as a whole, making it easier to use in small household smart devices, further promoting the miniaturization and cost optimization of smart home devices. The present application sets the resonant main frequency of the microstrip antenna between 5.725MHz and 5.850MHz, so that the microstrip antenna can achieve efficient signal transmission in the 5.8G frequency band. It is suitable for wireless communication devices that require high data transmission rates, such as smart door locks and smart doorbells in smart homes, ensuring the response speed and communication quality of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting part of this application are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 A schematic structural diagram of a microstrip antenna according to an optional embodiment of the present invention is shown;

[0026] Figure 2 A schematic structural diagram of a microstrip antenna according to another optional embodiment of the present invention is shown;

[0027] Figure 3 Shown Figure 2 A perspective view of the microstrip antenna from one angle;

[0028] Figure 4 Shown Figure 3 Schematic diagram of the positional relationship between the second metal plate and the feed connector.

[0029] The above drawings include the following reference numerals:

[0030] 10. Antenna radiator; 20. Dielectric layer; 30. Reference ground layer; 31. First PCB board; 32. First metal plate; 40. Routing layer; 41. Second PCB board; 42. Second metal plate; 50. Feed port; 60. Feed connector; 70. Clearance area. DETAILED DESCRIPTION

[0031] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0033] In the present invention, unless otherwise specified, directional words such as "up, down, top, bottom" are usually used with reference to the directions shown in the drawings, or with reference to the components themselves in the vertical, perpendicular or gravity direction; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above directional words are not used to limit the present invention.

[0034] The principle of infrared detection technology is to use infrared sensors to monitor changes in thermal radiation in the surrounding environment to determine whether there is any object moving. However, this technology is strongly affected by environmental factors, resulting in a high false alarm rate. This is specifically manifested in the following aspects:

[0035] Regarding ambient temperature changes: Infrared sensors are sensitive to temperature, and even slight fluctuations in ambient temperature, such as from direct sunlight or air conditioning, can cause false alarms. For example, when the sun rises or sets, the rapid change in indoor and outdoor temperature can trigger an infrared detector alarm, even though there is no real security threat.

[0036] From the perspective of the uncertainty of the heat source of an object: infrared detection technology relies on the thermal radiation of the object, but small animals, obstacles or non-biological heat sources (such as light bulbs, electrical appliances) may also produce thermal radiation signals similar to those of the human body, causing the system to misjudge and generate false alarms.

[0037] In terms of obstruction and multipath effects: Infrared signals are easily obstructed. When obstructed by objects such as curtains, furniture, or walls, the sensor's sensitivity decreases, potentially leading to false alarms or missed detections. Furthermore, signals are reflected by obstacles, creating multipath signals, making it difficult for the system to accurately distinguish between real targets and interference signals.

[0038] In terms of electromagnetic interference: infrared detection equipment is susceptible to electromagnetic interference from other electronic devices, such as household appliances, wireless network signals, etc., which can also lead to false alarms.

[0039] From the perspective of the impact of pets and non-living objects: In a home environment, the activities of pets or changes in the position of non-living objects (such as wind-blown curtains) may also cause infrared sensors to mistakenly identify them as human activities, thereby triggering an alarm.

[0040] The limitations of infrared detection technology, particularly its high false alarm rate, significantly impact the reliability of smart home device monitoring, reduce user experience, and increase unnecessary alarm processing. Therefore, finding a new technology solution that can effectively reduce false alarm rates and improve monitoring accuracy has become a pressing need in the smart home industry.

[0041] Given the high false alarm rate associated with infrared detection technology, this utility model proposes a microstrip antenna design to provide a more reliable and accurate monitoring method for smart home devices. By incorporating radar technology, this high false alarm rate of infrared detection can be overcome, enabling accurate identification and location of moving objects, thereby improving the overall performance and user experience of smart home devices.

[0042] Next, we will further introduce the design details of the microstrip antenna of this utility model and how it overcomes the shortcomings of existing infrared detection technology.

[0043] like Figures 1 to 4 As shown, the microstrip antenna includes an antenna radiator 10, a dielectric layer 20, a reference ground layer 30 and a routing layer 40 stacked in sequence. The microstrip antenna also includes a radar component, which is arranged in the routing layer 40. The radar component includes at least two feed ports 50. The antenna radiator 10 is signal-connected to the feed ports 50, wherein the at least two feed ports 50 include at least one signal receiving feed port and at least one signal transmitting feed port. The resonant main frequency of the microstrip antenna is greater than or equal to 5725 MHz and less than or equal to 5850 MHz.

[0044] By providing at least two feed ports 50 within the routing layer 40, the microstrip antenna of the present invention is capable of simultaneously receiving and transmitting signals. At least one signal receiving feed port is responsible for receiving the echo signal, while at least one signal transmitting feed port is responsible for transmitting the initial signal. This dual-feed design overcomes the limitations of traditional single-feed antennas in radar functionality and improves the overall performance and flexibility of the radar system. By integrating the radar component within the routing layer 40 of the microstrip antenna, the present invention achieves close coupling between the antenna and the radar chip, reducing the complexity and cost of traditional designs that separate the antenna and radar component. This highly integrated design not only simplifies the assembly and debugging of the device, but also makes the antenna more compact as a whole, making it easier to use in small household smart devices, further promoting the miniaturization and cost optimization of smart home devices. The present application sets the resonant main frequency of the microstrip antenna between 5.725MHz and 5.850MHz, enabling the microstrip antenna to achieve efficient signal transmission within the 5.8G frequency band. It is suitable for wireless communication devices that require high data transmission rates, such as smart door locks and smart doorbells in smart homes, ensuring the response speed and communication quality of the device.

[0045] Compared with infrared technology, the microstrip antenna of the present application can provide more stable all-weather monitoring capabilities. Whether it is day or night, sunny or rainy, the antenna can maintain stable performance and is not significantly affected by changes in ambient light and temperature, thereby ensuring the reliability and accuracy of the monitoring results. By integrating radar components into the microstrip antenna, false alarms can be significantly reduced and monitoring accuracy can be improved. The radar system can distinguish between different types of objects, including human bodies, pets, non-living objects, etc., and by analyzing the characteristics of the echo signal (such as frequency, time, phase), the microstrip antenna in the present invention can more accurately determine the nature and position of the moving object, thereby avoiding false alarms caused by environmental changes or non-target objects.

[0046] In some alternative embodiments, see Figure 1 Antenna radiator 10 is congruently placed on the surface of dielectric layer 20 facing away from reference ground layer 30. By optimizing the layout of antenna radiator 10, not only is the antenna's efficiency, gain, and directivity improved, but multipath effects and interference are also reduced. This enhances the antenna's miniaturization, integration, stability, and durability, as well as its coupling with radar components, ultimately improving monitoring accuracy. This design is particularly suitable for smart home devices that require high-performance monitoring in confined spaces, such as smart door locks, pet monitors, and elderly care systems, helping to improve monitoring accuracy and user experience.

[0047] In some alternative embodiments, see Figure 2 and Figure 3 , the area of ​​the antenna radiator 10 is smaller than the area of ​​the surface of the dielectric layer 20 in contact with the antenna radiator 10. When the area of ​​the antenna radiator 10 is smaller than the area of ​​the contact surface with the dielectric layer 20, the electromagnetic wave loss in the dielectric layer 20 can be effectively reduced. During the operation of the antenna, electromagnetic waves will propagate and radiate in the dielectric layer 20. If the radiator area is too large, it may cause more electromagnetic waves to be reflected and attenuated inside the dielectric layer 20, thereby increasing energy loss. A smaller area of ​​the antenna radiator 10 can reduce this loss and improve the radiation efficiency of the antenna. Especially under high-frequency working conditions such as 5.8G, the impact of dielectric loss on antenna efficiency is more significant. Therefore, an optimized radiator area design helps to maintain the high performance of the antenna.

[0048] The area of ​​the antenna radiator 10 is closely related to the antenna's directivity. A smaller area of ​​the antenna radiator 10 helps form a sharper radiation pattern and reduces the antenna's sidelobe levels, which in turn reduces the amount of non-primary radiation that is detrimental to signal transmission. This is particularly important for smart home devices, as they often need to monitor or communicate in a specific direction. Reducing sidelobes means the antenna has higher signal strength in that target direction and is less sensitive to external interference.

[0049] Furthermore, a smaller antenna radiator 10 can improve the antenna's anti-interference capabilities. A larger antenna radiator 10 would pick up signals from all directions, potentially including interference from other electronic devices. A smaller antenna radiator, through its more concentrated radiation characteristics, can more effectively filter out signals from non-target directions, thereby maintaining signal clarity in complex environments.

[0050] By reducing the area of ​​antenna radiator 10, antenna miniaturization is achieved, which is crucial in space-constrained smart home devices. A smaller antenna not only saves space within the device but also simplifies assembly and production, improving overall device integration and reducing costs. Furthermore, a miniaturized antenna is easier to integrate with other components such as the radar chip and power module on the same PCB, improving the device's compactness and functional integration.

[0051] In some alternative embodiments, see Figure 1 and Figure 2 The antenna radiator 10 is coaxial with the dielectric layer 20. When the antenna radiator and dielectric layer are coaxial, and the central axis of the antenna radiator 10 coincides with the central axis of the dielectric layer 20, the electromagnetic energy transmission path between the antenna radiator 10 and the dielectric layer 20 becomes the shortest, which helps reduce signal transmission losses. During electromagnetic wave transmission, if the path deviates from the central axis, it will experience more dielectric loss, resulting in weakened signal strength. The coaxial design ensures optimal coupling between the radiator and the dielectric layer, minimizing energy loss and improving antenna efficiency when receiving and transmitting signals.

[0052] In some alternative embodiments, see Figure 3 , the antenna radiator 10 is a centrally symmetrical pattern. The centrally symmetrical antenna radiator 10 helps to form a more uniform and symmetrical radiation pattern, which can effectively reduce the non-uniformity in the radiation direction, that is, reduce the side lobes. Side lobes refer to radiation outside the main radiation direction, which may cause unnecessary interference and signal loss. The centrally symmetrical antenna design can optimize the directivity of the antenna, enhance the signal strength in the main radiation direction, and effectively suppress the side lobes, thereby improving the communication quality and monitoring accuracy of the antenna in the target direction. When designing high-frequency antennas, there is often a trade-off between size optimization and performance assurance. The radiator design with a centrally symmetrical pattern can ensure good radiation efficiency and gain while keeping the antenna miniaturized. This helps to achieve high-performance antennas in a limited space, and is particularly suitable for space-constrained smart home devices such as smart door locks, surveillance cameras, etc., which saves space while maintaining high antenna efficiency.

[0053] In some alternative embodiments, see Figure 3, at least one side of the antenna radiator 10 is arranged at an angle to at least one side of the dielectric layer 20. The side of the antenna radiator 10 is arranged at an angle to the side of the dielectric layer 20, which can effectively utilize space and reduce the physical size of the antenna, especially the planar area of ​​the antenna. In high-frequency applications such as 5.8G radar antennas, reducing the size of the antenna is crucial for the miniaturization of the device. Reducing the planar coverage of the antenna through geometric optimization not only saves space inside the device, but also facilitates integration with other electronic components, such as radar chips, power modules, etc., thereby improving the portability and design flexibility of the device.

[0054] For example, the antenna radiator 10 is square and the dielectric layer 20 is rectangular, and the side of the antenna radiator 10 is arranged at an angle to the long side of the dielectric layer 20. For example, the angle between the side of the antenna radiator 10 and the long side of the dielectric layer 20 is 45 degrees, so that the antenna radiator 10 radiates uniformly.

[0055] In some alternative embodiments, see Figure 3 The antenna radiator 10 is square, and its length is greater than or equal to 6.2 mm and less than or equal to 10.2 mm. The square shape of the antenna radiator 10 helps form a more uniform directional radiation pattern, especially when its length matches the wavelength of the antenna's operating frequency. In the 5.8 GHz frequency band, by adjusting the radiator's size, its radiation characteristics can be optimized, resulting in similar radiation intensities in both the horizontal and vertical directions. This is particularly important in smart home devices, as these devices may need to monitor in multiple directions, and a square antenna can provide more balanced coverage. When the length of the antenna radiator 10 is set between 6.2 mm and 10.2 mm, this dimension falls within the antenna's designed "resonance length," meaning the antenna can achieve high efficiency and gain in the 5.8 GHz frequency band. The resonant length is a relationship between antenna size and operating frequency that maximizes the electromagnetic energy radiated by the antenna. Within this size range, the square shape of the antenna radiator 10 more efficiently converts input power into radiated power, thereby improving the strength of the monitoring signal.

[0056] Furthermore, the size of the antenna radiator 10 directly affects the antenna's operating frequency band and bandwidth. By setting the radiator size between 6.2 mm and 10.2 mm, the antenna maintains a good bandwidth within the 5.8 GHz band. This means the antenna can effectively receive and transmit signals within this frequency band while minimizing frequency offset and signal attenuation, improving communication stability and monitoring reliability.

[0057] While maintaining high performance, controlling the size of the antenna radiator 10 facilitates miniaturization. This is crucial for smart home devices, as limited internal space demands the most compact components possible. Miniaturization not only saves space but also facilitates close integration of the antenna radiator 10 with other electronic components (such as radar chips and power circuits), improving the overall device integration and production efficiency.

[0058] For example, in Figure 3 In the specific embodiment shown, the antenna radiator 10 is a cube with a length of 8.2 mm and is placed at a 45° angle in the middle of the dielectric layer 20, and there is a 4.2 mm clearance area 70 around the antenna radiator 10; this clearance design can ensure signal isolation between the antenna radiator 10 and the edge of the dielectric layer 20, reduce signal interference, and improve the antenna's anti-interference ability. It is suitable for scenarios that need to work in complex electromagnetic environments, such as smart access control systems in cities, ensuring the stability and reliability of the equipment.

[0059] In some alternative embodiments, see Figure 1 and Figure 2 The reference ground layer 30 includes a first PCB board 31 and a first metal plate 32. The first PCB board 31 is connected to the surface of the dielectric layer 20 away from the antenna radiator 10, and the first metal plate 32 is connected to the surface of the first PCB board 31 away from the dielectric layer 20. The first metal plate 32 is the reference ground of the microstrip antenna. Using the first PCB board 31 as a bridge connecting the dielectric layer 20 and the first metal plate 32 can ensure stable electromagnetic coupling between the antenna radiator 10 and the reference ground layer 30. This coupling helps reduce signal loss in the antenna structure and improve the efficiency of the antenna. Proper selection of the dielectric constant and thickness of the first PCB board 31 can further optimize the coupling effect, reduce electromagnetic wave reflection in the medium, and thus improve the purity and strength of signal transmission.

[0060] By rationally designing the dimensions and layout of the first PCB 31 and the first metal plate 32, antenna miniaturization can be achieved while maintaining antenna performance. This is particularly important for smart home devices that require antenna integration within limited space, such as smart door locks or wireless cameras. Miniaturization not only saves space but also simplifies the device assembly process, improving overall integration and aesthetics.

[0061] The coordination of the first PCB 31, dielectric layer 20, and first metal plate 32 helps maintain the stability of the antenna structure and mitigate performance fluctuations caused by vibration or temperature changes. Furthermore, this design improves the antenna's input impedance matching, ensuring a good connection between the antenna and the radar chip or signal source, reducing reflection loss, and enhancing signal transmission efficiency and overall antenna performance.

[0062] Optionally, the first metal plate 32 is a copper clad plate.

[0063] In some optional embodiments, the thickness of the first PCB 31 is greater than or equal to 0.9 mm and less than or equal to 1.5 mm. The thickness of the first PCB 31 directly affects its electromagnetic wave transmission characteristics as a medium. In the microstrip design of a 5.8G radar antenna, this thickness range helps reduce dielectric loss and minimizes reflection and attenuation of electromagnetic waves within the first PCB 31, thereby improving signal transmission efficiency and overall antenna performance. Dielectric loss is related to the thickness and dielectric constant of the first PCB 31. An appropriate thickness ensures low antenna loss within the target frequency band, which is particularly important for high-frequency applications.

[0064] Furthermore, the thickness of the first PCB 31 affects the antenna's resonant frequency and bandwidth. Within the aforementioned thickness range, the first PCB 31 provides a stable resonant environment for the antenna, facilitating the design of an antenna with an appropriate bandwidth and ensuring good performance within the 5.8 GHz band. For smart device monitoring systems that require stable performance across a wide frequency band, accurately controlling the PCB thickness is crucial.

[0065] In addition, the thickness of the first PCB board 31 is between 0.9 mm and 1.5 mm, which helps to miniaturize the antenna. In space-constrained smart home devices such as smart doorbells, pet monitors, or indoor wireless cameras, a compact antenna design can save valuable internal space while facilitating the integration of the antenna with components such as radar chips and power circuits, thereby improving the overall integration and design flexibility of the device. However, as part of the antenna structure, the thickness of the first PCB board 31 also affects the antenna's heat dissipation capacity. The first PCB board, with a thickness range of 0.9 mm to 1.5 mm, not only supports the antenna structure, but also serves as a heat dissipation medium, helping the antenna maintain a lower temperature during high-power operation, thereby improving its stability and service life. This is very important for ensuring the reliability of long-term monitoring tasks.

[0066] For example, the thickness of the first PCB board 31 is 1.2 mm, the length of the first PCB board 31 is 43 mm, and the width of the first PCB board 31 is 28 mm.

[0067] In some alternative embodiments, see Figure 1 and Figure 2 The routing layer 40 includes a second PCB board 41 and a second metal plate 42. The second PCB board 41 is connected to the surface of the reference ground layer 30 away from the dielectric layer 20. The second metal plate 42 is connected to the surface of the second PCB board 41 away from the reference ground layer 30. The radar component is connected to the second metal plate 42, and the second metal plate 42 has a feeding port 50.

[0068] To enhance signal transmission efficiency and integrity, the second metal plate 42, as part of the feed port 50 and routing layer 40, provides a low-impedance path, ensuring efficient and complete transmission of radar signals from the radar assembly to the antenna radiator 10. The low impedance of the second metal plate 42 reduces signal attenuation and reflection during transmission, thereby improving signal quality. This is particularly important for high-frequency signals such as 5.8 GHz radar waves, which are more sensitive to impedance variations in the transmission path.

[0069] Furthermore, the combination of the second PCB 41 and the second metal plate 42 forms an effective shielding layer, reducing radar signal interference with surrounding electronic devices while also protecting the radar assembly from external electromagnetic noise. This shielding effect is crucial for improving the overall electromagnetic compatibility of smart home devices, especially in densely populated homes or in complex electromagnetic environments. As part of the routing layer 40, the second metal plate 42 carries the radar assembly's feed lines and other important circuits, reducing the complexity of the circuit routing on the antenna board and improving device integration and production efficiency.

[0070] Optionally, the second metal plate 42 is a copper clad plate.

[0071] In some optional embodiments, the thickness of the second PCB board 41 is greater than or equal to 0.09 mm and less than or equal to 0.15 mm. The thickness of the second PCB board 41 directly affects its dielectric constant, which in turn affects the resonant frequency in antenna design. In microstrip antennas, the resonant frequency is a key parameter for antenna performance, determining the antenna's operating frequency band. For 5.8 GHz radar antennas, the dielectric constant of the second PCB board 41 requires careful design to ensure good resonant characteristics within the target frequency band. Setting an appropriate thickness helps precisely control the dielectric constant, thereby achieving stable operation of the antenna within the 5.8 GHz frequency band and improving the efficiency of receiving and transmitting monitoring signals. The thickness of the second PCB board 41 is closely related to the coupling efficiency of the antenna radiator 10. A second PCB board 41 that is too thin may not provide sufficient support and current return, affecting the antenna's radiation efficiency. On the other hand, a second PCB board 41 that is too thick will increase additional dielectric loss, reducing antenna performance. The thickness is set between 0.09 mm and 0.15 mm, which can keep the dielectric loss at a low level while providing sufficient support to ensure the integrity of the current loop between the antenna radiator and the reference ground layer, thereby improving the radiation efficiency of the antenna and reducing energy loss.

[0072] In addition, the thickness of the second PCB board 41 will affect the bandwidth of the antenna, that is, the range in which the antenna maintains efficient radiation within a specific frequency range. In the 5.8G frequency band, controlling the bandwidth is crucial to achieving stable and reliable operation. Setting an appropriate PCB board thickness can adjust the bandwidth of the antenna, ensuring that the antenna has good working performance in the 5.8G frequency band, while reducing interference with adjacent frequency bands and improving the purity and stability of the monitoring signal. While meeting performance requirements, setting the thickness of the second PCB board between 0.09 mm and 0.15 mm helps to miniaturize the antenna, which is very important for space-constrained smart home devices. The miniaturized antenna can be more easily integrated with other electronic components such as radar chips and power modules on the second PCB board 41, improving the overall integration and production efficiency of the equipment while reducing costs.

[0073] For example, in Figure 4 In the illustrated embodiment, two metal discs are provided on the second metal plate 42. The metal discs serve as feed ports 50 and are connected to the feed probes. For another example, the radius of the metal discs is 0.2 mm. For example, the thickness of the second PCB 41 is 0.12 mm, the length of the second PCB 41 is 43 mm, and the width of the second PCB 41 is 28 mm.

[0074] In some optional embodiments, such as Figures 1 to 4 As shown, the microstrip antenna also includes at least two feed connectors 60, and the two ends of the feed connector 60 are respectively connected to the feed port 50 and the antenna radiator 10. The use of the feed connector 60 enables the antenna to perform dual-feed or multi-feed operation, which means that the antenna can simultaneously receive or transmit signals through multiple independent feed connectors 60. In the application of 5.8G radar antennas, two or more feed connectors 60 can be connected to the signal receiving feed port and the signal transmitting feed port of the antenna respectively, so that the receiving and transmitting functions of the antenna can be performed simultaneously, thereby improving the flexibility and efficiency of the antenna. Dual-feed operation is particularly suitable for smart home devices that need to monitor and communicate simultaneously, such as smart door locks and surveillance cameras, ensuring the stability and reliability of the system in two-way communication. For example, the feed connector 60 is a feed probe, and for another example, the radius of the feed probe is 0.1 mm.

[0075] For example, the second PCB board 41, the reference ground layer 30 and the dielectric layer 20 all have vias, and the feed probe is disposed in the vias. For another example, the radius of the vias is 1 mm.

[0076] In some alternative embodiments, see Figure 1 and Figure 2The orthographic projection of the dielectric layer 20 on the routing layer 40 and the orthographic projection of the reference ground layer 30 on the routing layer 40 completely overlap with the routing layer 40. When the dielectric layer 20, the reference ground layer 30, and the routing layer 40 completely overlap vertically, the antenna structure forms a closed electromagnetic wave transmission path, which helps reduce electromagnetic wave leakage and loss during transmission and improves signal transmission efficiency. In 5.8G radar antennas, maintaining signal strength and clarity is crucial for monitoring accuracy. This design ensures that the antenna maintains good performance in high-frequency environments.

[0077] Impedance matching is a key factor in antenna design. It ensures consistent impedance between the antenna and the feed system, reducing signal reflections and improving energy transmission efficiency. The complete overlap of the dielectric layer 20, the reference ground layer 30, and the routing layer 40 creates a stable electromagnetic environment, helping to optimize the antenna's input impedance, achieving a good match with the feed system, such as the radar chip, reducing energy loss, and improving the antenna's overall performance.

[0078] Furthermore, the layout of dielectric layer 20 and reference ground layer 30 directly influences the antenna's radiation characteristics, including its radiation pattern and bandwidth. A fully overlapping design ensures that the antenna radiator 10 has higher gain in the direction away from dielectric layer 20, while also controlling sidelobe levels and reducing interference in other directions. This is crucial for smart home devices requiring directional monitoring, such as smart doorbells or pet monitoring systems, as it ensures optimal antenna monitoring within a specific area.

[0079] However, when the dielectric layer 20, the reference ground layer 30 and the routing layer 40 are completely overlapped in orthographic projection, the microstrip antenna can be designed to be more compact, which helps to achieve miniaturization of the antenna, which is particularly important for home smart devices with limited space.

[0080] In some optional embodiments, the dielectric layer 20 is rectangular, with a length greater than or equal to 33 mm and less than or equal to 53 mm; a width greater than or equal to 18 mm and less than or equal to 38 mm; and a thickness greater than or equal to 0.09 mm and less than or equal to 0.15 mm. This design ensures that the dielectric layer meets antenna performance requirements while also meeting the stringent size requirements of miniaturized products, such as smart door locks and smart doorbells, ensuring portability and aesthetics. The design parameters of the dielectric layer 20, including its length, width, and thickness, have a direct and significant impact on the performance of the microstrip antenna. The dimensions of the dielectric layer 20 directly affect the antenna's resonant frequency. A rectangular design within a specific length and width range ensures the antenna achieves optimal resonant frequency within the 5.8 GHz band. Accurate control of the resonant frequency is fundamental to antenna design, determining the antenna's operating frequency band and performance parameters, such as radiation efficiency and directivity. By precisely adjusting the dimensions of the dielectric layer, the antenna's resonant characteristics can be optimized, ensuring efficient operation within the target frequency band.

[0081] However, the shape and size of the dielectric layer 20 affect the radiation pattern of the antenna, that is, the spatial distribution of the antenna's radiated energy. A rectangular dielectric layer with dimensions within a specified range can help design an antenna with specific directivity and beam width. This is crucial for smart home devices that require directional monitoring, such as smart doorbells or pet monitoring systems. An optimized radiation pattern can improve the purity and accuracy of the monitoring signal, reduce the false alarm rate, and enhance the monitoring capability of the device. The thickness of the dielectric layer 20 has a direct impact on the bandwidth of the antenna. Setting the thickness between 0.09 mm and 0.15 mm helps design an antenna with an appropriate bandwidth to ensure stable performance within the 5.8G frequency band. Wideband antennas can cover a wider frequency range and improve the antenna's adaptability to frequency fluctuations, which is particularly important for smart devices operating in complex electromagnetic environments.

[0082] Furthermore, the thickness and dielectric constant of dielectric layer 20 determine signal transmission efficiency. Within a thickness range of 0.09 to 0.15 mm, the dielectric layer maintains low dielectric loss, improving signal transmission efficiency and reducing energy loss during transmission. This is particularly important for high-frequency 5.8GHz radar signals, ensuring signal strength and integrity and improving the stability of the monitoring system.

[0083] For example, the thickness of the dielectric layer 20 is 0.12 mm, the length of the dielectric layer 20 is 43 mm, and the width of the dielectric layer 20 is 28 mm.

[0084] The microstrip antenna of the utility model has a simple structure and can be used as a single device in a system without the need for separate debugging. It also has both receiving and transmitting functions and is suitable for doorbells, bells, and door locks.

[0085] In another optional embodiment of the present invention, the monitoring device includes the aforementioned microstrip antenna. By adopting the optimized microstrip antenna, the monitoring device can achieve efficient signal transmission within the 5.8 GHz frequency band. This not only meets the size requirements of miniaturized products such as smart door locks and smart doorbells, but also ensures high efficiency and low loss in terms of performance. This design is particularly suitable for application scenarios with high requirements for both size and performance, such as smart security systems and IoT devices. It provides strong technical support for smart access control and IoT devices, ensuring the device's response speed, communication quality, and stability, while maintaining good anti-interference capabilities in complex electromagnetic environments, thereby improving the device's reliability and practicality. In miniaturized products such as smart door locks and smart doorbells, this antenna design not only provides stable wireless communication, but also ensures the device's aesthetics and portability, providing users with a more convenient and safer user experience. In IoT devices, this antenna design can ensure efficient data transmission in various environments, providing technical support for the widespread application of the IoT.

[0086] For example, the monitoring device can be a small household product with monitoring functions, such as a doorbell, bell, door lock, etc.

[0087] Obviously, the embodiments described above are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0088] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, tasks, devices, components and / or combinations thereof.

[0089] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0090] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A microstrip antenna, characterized in that: The invention comprises an antenna radiator (10), a dielectric layer (20), a reference ground layer (30) and a wiring layer (40) which are stacked in sequence. The microstrip antenna further comprises a radar component which is arranged in the wiring layer (40). The radar component comprises at least two feed ports (50). The antenna radiator (10) is signal-connected to the feed ports (50). The at least two feed ports (50) comprise at least one signal receiving feed port and at least one signal transmitting feed port. The resonant main frequency of the microstrip antenna is greater than or equal to 5725 MHz and less than or equal to 5850 MHz.

2. The microstrip antenna according to claim 1, wherein: The antenna radiator (10) is uniformly covered on a surface of the dielectric layer (20) that is away from the reference ground layer (30).

3. The microstrip antenna according to claim 1, wherein: The area of ​​the antenna radiator (10) is smaller than the area of ​​the surface of the dielectric layer (20) in contact with the antenna radiator (10).

4. The microstrip antenna according to claim 3, wherein: The antenna radiator (10) satisfies at least one of the following requirements: The antenna radiator (10) and the dielectric layer (20) are coaxial; The antenna radiator (10) is a centrally symmetrical figure; At least one side of the antenna radiator (10) is arranged at an angle to at least one side of the dielectric layer (20).

5. The microstrip antenna according to claim 3, wherein: The antenna radiator (10) is square, and the length of the antenna radiator (10) is greater than or equal to 6.2 mm and less than or equal to 10.2 mm.

6. The microstrip antenna according to any one of claims 1 to 5, characterized in that The reference ground layer (30) comprises a first PCB board (31) and a first metal plate (32); the first PCB board (31) is connected to a surface of the dielectric layer (20) away from the antenna radiator (10); the thickness of the first PCB board (31) is greater than or equal to 0.9 mm and less than or equal to 1.5 mm; the first metal plate (32) is connected to a surface of the first PCB board (31) away from the dielectric layer (20); the first metal plate (32) serves as a reference ground for the microstrip antenna; and / or The routing layer (40) includes a second PCB board (41) and a second metal plate (42), the second PCB board (41) is connected to the surface of the reference ground layer (30) away from the dielectric layer (20), and the thickness of the second PCB board (41) is greater than or equal to 0.09 mm and less than or equal to 0.15 mm; the second metal plate (42) is connected to the surface of the second PCB board (41) away from the reference ground layer (30), the radar component is connected to the second metal plate (42), and the second metal plate (42) has the feed port (50).

7. The microstrip antenna according to any one of claims 1 to 5, characterized in that: The microstrip antenna further comprises at least two feeding connectors (60), with two ends of the feeding connector (60) being respectively connected to the feeding port (50) and the antenna radiator (10).

8. The microstrip antenna according to any one of claims 1 to 5, characterized in that: The orthographic projection of the dielectric layer (20) on the routing layer (40) and the orthographic projection of the reference ground layer (30) on the routing layer (40) completely overlap with the routing layer (40).

9. The microstrip antenna according to claim 8, characterized in that: The dielectric layer (20) is rectangular, and the dielectric layer (20) satisfies at least one of the following conditions: The length of the dielectric layer (20) is greater than or equal to 33 mm and less than or equal to 53 mm; The width of the dielectric layer (20) is greater than or equal to 18 mm and less than or equal to 38 mm; The thickness of the dielectric layer (20) is greater than or equal to 0.09 mm and less than or equal to 0.15 mm.

10. A monitoring device, characterized in that: The microstrip antenna comprises the microstrip antenna according to any one of claims 1 to 9.

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