Resistance-loaded and switch-controllable gain-adjustable patch antenna and application thereof

Abstract

The application discloses a gain-adjustable patch antenna based on resistance loading and switch control and application thereof. The patch antenna comprises a metal floor, a dielectric layer and a metal patch which are sequentially stacked, the metal patch is connected with at least one patch resistance through a micro switch, and the metal floor is connected with the patch resistance through a metal probe. Different resistance values of the patch resistance are selected according to needs, so that the gain of the patch antenna is adjustable, the number of the connected resistances is controlled by using the micro switch, and the gain of the patch antenna can be real-time graded and controlled. Compared with a conventional patch antenna, the gain-adjustable patch antenna provided by the application has a gain adjustment range of at least 6 dB, the identification range of the antenna can be adjusted according to the identification distance of a sensor product, and under the same profile, the gain-adjustable patch antenna provided by the application has a wider bandwidth and stronger working stability, and is particularly suitable for an antenna of a human body sensor in a smart home product.

Description

Technical Field

[0001] This invention belongs to the field of microwave communication technology and relates to a patch antenna and its application, specifically to a gain-adjustable patch antenna based on resistor loading and switch controllability and its application. Background Technology

[0002] In recent years, with the continuous development of sensors towards miniaturization, digitization, and intelligence, microwave radar has gradually become a competitive small-scale sensor solution. Based on the miniaturization requirements of sensors such as microwave radar, the demands on the size, weight, bandwidth, and other performance characteristics of antennas used in sensor wireless communication systems are becoming increasingly stringent. Patch antennas, due to their low profile, light weight, ease of fabrication, and low cost, are widely used in microwave radar module design. Currently, mainstream applications of microwave radar sensors cover gesture-sensing switches, personnel detection, pedestrian flow statistics, and vehicle recognition, requiring recognition ranges from 0.1 to 20 meters. These applications are complex, and the recognition distance varies widely. This necessitates that microwave radar sensors possess the ability to adjust the sensing distance in real time according to the application environment requirements.

[0003] Microwaves have strong penetrating power, which means that the Doppler waves emitted by microwave radar sensors may penetrate walls and identify people in other rooms or outside the room, thus causing false triggering problems and making it difficult to control the identification range. In addition, due to cost and miniaturization considerations, microwave sensors using commonly used frequency band chips usually do not have the function of output power adjustment, which requires the sensor antenna to have the corresponding gain adjustment capability.

[0004] However, there is currently little research on gain-tunable antennas in the industry, and the related technologies have low practicality. For example, the paper "An Electrically Actuated Liquid-Metal Gain-Reconfigurable Antenna" (GB Zhang, RCGough, MR Moorefield, KSElassy, ​​AT Ohta, and WA Shiroma, Int. J. Antennas Propag., 2018.) discloses a scheme to adjust the matching of patch antennas by changing the equivalent electrical length of liquid metal under different applied voltage biases, thereby achieving antenna gain reconfigurability. The paper "Controlling Gain Enhancement Using a Reconfigurable Metasurface Layer" (H. Almizan, ZAA Hassain, TA Elwi, and SMAl-Sabti, 12th Int. Symp. Adv. Top. Electr. Eng., ATEE 2021.) discloses a scheme to adjust antenna gain using graphene material with adjustable surface impedance. While the two aforementioned schemes achieve reconfigurable gain, they suffer from problems such as complex antenna structure, large size, reliance on special materials, and high cost, making it difficult to meet the requirements of microwave radar sensors for miniaturization and low cost.

[0005] In view of this, it is necessary to further improve the patch antenna in the existing technology. Summary of the Invention

[0006] Therefore, the technical problem to be solved by this invention is that existing gain-adjustable patch antennas have complex structures, large volumes, rely on special materials, and are costly. Thus, this invention proposes a gain-adjustable patch antenna with simple structure, small size, and low cost based on resistance loading and switch control, and its application.

[0007] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0008] The first aspect of the present invention provides a gain-adjustable patch antenna based on resistor loading and switch controllability, which includes a metal ground plane, a dielectric layer and a metal patch stacked sequentially, wherein the metal patch is connected to at least one patch resistor via a microswitch, and the metal ground plane is connected to the patch resistor via a metal probe.

[0009] Preferably, the cross-sectional shape of the metal patch is rectangular, and there are four patch resistors, each of which is connected to one of the four corners of the metal patch via a microswitch.

[0010] Preferably, the cross-sectional shape of the metal patch is rectangular, and there is one patch resistor, which is connected to the middle of one side of the metal patch via a micro switch.

[0011] Preferably, the cross-sectional shape of the metal patch is rectangular, and there are two patch resistors, each connected to opposite sides of the metal patch via a microswitch.

[0012] Preferably, the cross-sectional shape of the metal patch is rectangular, and there are four patch resistors, each of which is connected to the center of one of the four sides of the metal patch via a microswitch.

[0013] Preferably, the cross-sectional shape of the metal patch is circular or elliptical, and there is one patch resistor, which is connected to the center line of the metal patch via a micro switch.

[0014] Preferably, the device also includes a power supply port that penetrates the dielectric layer, with one end connected to the metal floor and the other end connected to the metal patch.

[0015] Preferably, the dielectric layer is an air dielectric layer or a dielectric substrate.

[0016] Preferably, the metal probe is connected to the side of the chip resistor away from the metal chip; the resistance of the chip resistor is 10-10000Ω.

[0017] A second aspect of the present invention provides an application of the aforementioned gain-adjustable patch antenna based on resistance loading and switch control in a human body sensor.

[0018] The technical solution of the present invention has the following advantages over the prior art:

[0019] This invention provides a gain-adjustable patch antenna based on resistor loading and switch control. It comprises a metal ground plane, a dielectric layer, and a metal patch stacked sequentially. The metal patch is connected to at least one patch resistor via a microswitch, and the metal ground plane is connected to the patch resistor via a metal probe. By setting the patch resistor and selecting different resistance values ​​as needed, the gain of the patch antenna is adjustable. Simultaneously, by connecting the metal patch and the patch resistor via the microswitch and controlling the number of connected resistors, the gain of the patch antenna can be adjusted in real-time in stages. Compared to traditional patch antennas, the gain-adjustable patch antenna provided by this invention has a gain adjustment range of at least 6dB, allowing adjustment of the antenna's recognition range according to the recognition distance requirements of the sensor product. Furthermore, under the same cross-section, the gain-adjustable patch antenna provided by this invention also has a wider bandwidth and stronger operational stability than conventional patch antennas. This patch antenna also has the advantages of simple structure, low cost, and high design freedom, making it particularly suitable for antennas of human body sensors in smart home products. Attached Figure Description

[0020] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0021] Figure 1 This is a cross-sectional view of the gain-adjustable patch antenna based on resistor loading and switch controllable provided in Embodiment 1 of the present invention;

[0022] Figure 2 This is a top view of the gain-adjustable patch antenna based on resistor loading and switch controllable provided in Embodiment 1 of the present invention;

[0023] Figure 3 This is a cross-sectional view of the gain-adjustable patch antenna based on resistor loading and switch controllable provided in Embodiment 2 of the present invention;

[0024] Figure 4 This is a top view of the gain-adjustable patch antenna based on resistor loading and switch controllable provided in Embodiment 3 of the present invention.

[0025] Figure 5 This is a top view of the gain-adjustable patch antenna based on resistor loading and switch controllable provided in Embodiment 4 of the present invention.

[0026] Figure 6 This is a top view of the gain-adjustable patch antenna based on resistor loading and switch controllable provided in Embodiment 5 of the present invention;

[0027] Figure 7 These are simulation and measured E-plane and H-plane gain diagrams of the patch antenna provided in Embodiment 1 of the present invention when no microswitch is provided, under different resistance values ​​of patch resistors;

[0028] Figure 8 This is the curve of the measured S11 reflection coefficient as a function of frequency when the patch antenna provided in Embodiment 1 of the present invention is not equipped with a microswitch;

[0029] Figure 9 This is a graph showing the E-plane gain of the patch antenna provided in Embodiment 1 of the present invention as a function of the number of microswitches turned on;

[0030] Figure 10 This is a graph showing the H-plane gain of the patch antenna provided in Embodiment 1 of the present invention as a function of the number of microswitches turned on.

[0031] The reference numerals in the figure are: 1-metal ground plane; 2-dielectric layer; 3-metal patch; 4-pattern resistor; 5-metal probe; 6-feed port; 7-micro switch. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0033] In the description of this invention, it should be understood that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed during use, or the orientation or positional relationship in which those skilled in the art would usually understand. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] The terms "first," "second," etc., used in this invention are merely for descriptive purposes and have no special meaning.

[0035] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "install" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] Example 1

[0037] This embodiment provides a gain-adjustable patch antenna based on resistor loading and switch controllability. Please refer to [link to relevant documentation]. Figure 1-2The gain-adjustable patch antenna based on resistance loading and switch control provided in this embodiment includes a metal ground plane 1, a dielectric layer 2 and a metal patch 3 stacked sequentially. The metal patch 3 is connected to at least one patch resistor 4 through a micro switch 7. Each patch resistor 4 is also connected to a metal probe 5. One end of the metal probe 5 is connected to the patch resistor 4, and the other end passes through the dielectric layer 2 and is connected to the metal patch 3, so that the patch resistor 4 is connected to the metal ground plane 1 through the metal probe 5.

[0038] This embodiment provides a gain-adjustable patch antenna based on resistor loading and switch control. By setting a patch resistor 4, and selecting patch resistors 4 with different resistance values ​​as needed, the gain of the patch antenna is adjustable. Simultaneously, a microswitch connects the metal patch and the patch resistor, and the microswitch controls the number of connected resistors, allowing for real-time, graded gain adjustment of the patch antenna. Compared to traditional patch antennas, the gain-adjustable patch antenna provided by this invention has a gain adjustment range of at least 6dB, thus allowing adjustment of the antenna's recognition range according to the recognition distance requirements of the sensor product. Furthermore, under the same cross-section, the gain-adjustable patch antenna provided by this invention also has a wider bandwidth and stronger operational stability than conventional patch antennas, making it particularly suitable for antennas used in human body sensors in smart home products.

[0039] In this embodiment, the dielectric layer 2 may be made of FR-4 material or other radio frequency substrate material, or as a variable implementation, the dielectric layer 2 may also be made of air.

[0040] The number and position of the chip resistors 4 can be varied. In this embodiment, preferably, the metal base plate 1, the dielectric layer 2, and the metal chip 3 all adopt a rectangular plate structure, and there are 4 chip resistors 4. Each chip resistor 4 is connected to the four corners of the metal chip 3 through a micro switch 7.

[0041] This configuration ensures that the applied resistors do not alter the internal field mode distribution of the metal patch 3, thus improving the patch's bandwidth performance. According to patch antenna theory, a potential difference is generated between the surface of the metal patch 3 and the surface of the metal ground plane 1 during operation. Consequently, current flows through the four patch resistors located at the four corners of the metal patch 3, resulting in power consumption. This power consumption reduces antenna efficiency and gain, and also lowers the antenna system's quality factor, thus widening the antenna bandwidth. As the resistance value of the patch resistor 4 changes, the current flowing through it and the resulting power consumption also change. Therefore, adjusting the resistance value of the patch resistor 4 achieves the technical effect of adjustable patch antenna gain. Furthermore, the metal patch 3 and the patch resistor 4 are connected via microswitches 7, allowing the electrical connection between them to be adjusted. The different numbers of the four microswitches 7 (0, 1, 2, 3, and 4 open) create five levels of gain control. According to patch antenna theory, the more resistors applied in this case, the lower the antenna gain and the wider the adjustment range. Furthermore, according to patch antenna cavity mode theory, since resistor loading is a purely resistive element, it hardly changes the patch's resonant mode. Therefore, the above gain adjustment will not change parameters such as the antenna's radiation direction.

[0042] Therefore, the patch antenna provided in this embodiment can adjust the gain of the patch antenna by loading resistors of different values ​​through the patch resistor 4, and at the same time expand the bandwidth of the patch antenna. This method of adjusting the gain of the patch antenna by loading resistors has the advantages of simple structure, low cost and high design freedom. At the same time, by turning on different numbers of microswitches 7, the gain of the patch antenna can be controlled in stages. Due to the characteristics of the microswitches 7, the antenna gain can be quickly and dynamically adjusted in multiple stages according to the working environment, which is very convenient.

[0043] To expand the adjustable range of the patch antenna gain, the resistance of the patch resistor 4 is 10-10000Ω. Different resistance values ​​of the patch resistor 4 can be selected and loaded onto the metal patch 3 according to different needs.

[0044] Furthermore, as shown in the figure, the metal probe 5 is connected to the side of the chip resistor 4 away from the metal chip 3, so that the metal probe 5 and the metal chip 3 are connected through the chip resistor 4.

[0045] To enable the patch antenna to supply power, the gain-adjustable patch antenna based on resistor loading and switch control provided in this embodiment also includes a feed port 6. The feed port 6 penetrates the dielectric layer 2, with one end connected to the metal ground plane 1 and the other end connected to the metal patch 3.

[0046] This embodiment also provides an application of the above-mentioned gain-adjustable patch antenna based on resistance loading and switch control in human body sensors of smart home products such as smart lights.

[0047] Example 2

[0048] This embodiment provides a gain-adjustable patch antenna based on resistor loading and switch controllability. Please refer to [link to relevant documentation]. Figure 3 The structure of this patch antenna is basically the same as that of Embodiment 1, including a metal ground plane 1, a dielectric layer 2 and a metal patch 3 stacked in sequence. The metal patch 3 is connected to a patch resistor 4 through a micro switch 7. The patch resistor 4 is also connected to a metal probe 5. One end of the metal probe 5 is connected to the patch resistor 4, and the other end passes through the dielectric layer 2 and is connected to the metal patch 3, so that the patch resistor 4 is connected to the metal ground plane 1 through the metal probe 5.

[0049] In this embodiment, the dielectric layer 2 is made of FR4 material. The metal ground plane 1, dielectric layer 2, and metal patch 3 are all rectangular plate structures. The difference from embodiment 1 is that there is one patch resistor 4. Correspondingly, there is also one micro switch 7. As shown in the figure, the patch resistor 4 is connected to one side of the rectangular metal patch 3 through the micro switch 7 and is located at the center line of that side of the metal patch 3. That is, the micro switch 7 and the patch resistor 4 are located in the middle of that side of the metal patch 3.

[0050] Among them, the resistance of the chip resistor 4 is 10-10000Ω, and the metal probe 5 is connected to the side of the chip resistor 4 away from the metal patch 3, so that the metal probe 5 and the metal patch 3 are connected through the chip resistor 4.

[0051] To enable the patch antenna to supply power, the gain-adjustable patch antenna based on resistor loading and switch control provided in this embodiment also includes a feed port 6. The feed port 6 penetrates the dielectric layer 2, with one end connected to the metal ground plane 1 and the other end connected to the metal patch 3.

[0052] The gain-adjustable patch antenna based on resistor loading and switch control provided in this embodiment achieves gain adjustment control of the patch antenna by setting a patch resistor 4 in the center of one side of the metal patch 3. At the same time, by setting a micro switch 7, the electrical connection control between the metal patch 3 and the patch resistor 4 is realized by controlling the opening and closing of the micro switch 7, thereby further realizing gain adjustment of the patch antenna. This patch antenna requires fewer patch resistors 4 and has a simpler structure.

[0053] This embodiment also provides an application of the above-mentioned gain-adjustable patch antenna based on resistance loading and switch control in human body sensors of smart home products such as smart lights.

[0054] Example 3

[0055] This embodiment provides a gain-adjustable patch antenna based on resistor loading and switch controllability. Please refer to [link to relevant documentation]. Figure 4 The structure of this patch antenna is basically the same as that of Embodiment 1, including a metal ground plane 1, a dielectric layer 2 and a metal patch 3 stacked in sequence. The metal patch 3 is connected to a patch resistor 4 through a micro switch 7. The patch resistor 4 is also connected to a metal probe 5. One end of the metal probe 5 is connected to the patch resistor 4, and the other end passes through the dielectric layer 2 and is connected to the metal patch 3, so that the patch resistor 4 is connected to the metal ground plane 1 through the metal probe 5.

[0056] In this embodiment, the dielectric layer 2 adopts an FR4 dielectric substrate, and the metal ground plane 1, dielectric layer 2, and metal patch 3 all adopt a rectangular plate structure. The difference from embodiment 1 is that there are two patch resistors 4, and correspondingly, there are also two microswitches 7. As shown in the figure, each of the two patch resistors 4 is connected to the opposite sides of the rectangular metal patch 3 through a microswitch 7.

[0057] Among them, the resistance of the chip resistor 4 is 10-10000Ω, and the metal probe 5 is connected to the side of the chip resistor 4 away from the metal patch 3, so that the metal probe 5 and the metal patch 3 are connected through the chip resistor 4.

[0058] To enable the patch antenna to supply power, the gain-adjustable patch antenna based on resistor loading and switch control provided in this embodiment also includes a feed port 6. The feed port 6 penetrates the dielectric layer 2, with one end connected to the metal ground plane 1 and the other end connected to the metal patch 3.

[0059] This embodiment provides a gain-adjustable patch antenna based on resistance loading and switch control. By placing patch resistors 4 at the center of opposite sides of a metal patch 3, the gain of the patch antenna can be adjusted and controlled from both sides of the metal patch 3. According to the cavity mode theory of patch antennas, when the patch antenna operates in TM01 mode, the electric field intensity on the surface of the metal patch 3 changes with the edge position. By placing the two patch resistors 4 at different positions on opposite sides of the metal patch 3, the voltage difference across the metal patch 3 can be controlled, thereby controlling the efficiency of the patch antenna and adjusting its gain. Simultaneously, by placing a microswitch 7 between the metal patch 3 and the patch resistors 4, the electrical connection between different numbers of patch resistors 4 and the metal patch 3 can be controlled, achieving a graded control effect of the patch antenna gain.

[0060] This embodiment also provides an application of the above-mentioned gain-adjustable patch antenna based on resistance loading and switch control in human body sensors of smart home products such as smart lights.

[0061] Example 4

[0062] This embodiment provides a gain-adjustable patch antenna based on resistor loading and switch controllability. Please refer to [link to relevant documentation]. Figure 5The structure of this patch antenna is basically the same as that of Embodiment 1, including a metal ground plane 1, a dielectric layer 2 and a metal patch 3 stacked in sequence. The metal patch 3 is connected to a patch resistor 4 through a micro switch 7. The patch resistor 4 is also connected to a metal probe 5. One end of the metal probe 5 is connected to the patch resistor 4, and the other end passes through the dielectric layer 2 and is connected to the metal patch 3, so that the patch resistor 4 is connected to the metal ground plane 1 through the metal probe 5.

[0063] In this embodiment, the dielectric layer 2 adopts an FR4 dielectric substrate, and the metal ground plane 1, dielectric layer 2, and metal patch 3 all adopt a rectangular plate structure. There are 4 patch resistors 4, and correspondingly, there are also 4 microswitches 7. The difference from embodiment 1 is that, as shown in the figure, each patch resistor 4 is connected to the four sides of the rectangular metal patch 3 through a microswitch 7 and is located at the midline of the four sides of the metal patch 3. That is, the patch resistor 4 is set in the middle of that side of the metal patch 3 through the microswitch 7.

[0064] Among them, the resistance of the chip resistor 4 is 10-10000Ω, and the metal probe 5 is connected to the side of the chip resistor 4 away from the metal patch 3, so that the metal probe 5 and the metal patch 3 are connected through the chip resistor 4.

[0065] To power the patch antenna, the gain-adjustable patch antenna based on resistor loading and switch control provided in this embodiment also includes a feed port 6. The feed port 6 penetrates the dielectric layer 2, with one end connected to the metal ground plane 1 and the other end connected to the metal patch 3. In this embodiment, the feed port 6 is located on one diagonal of the rectangular metal patch 3. Simultaneously, four patch resistors 4 are positioned at the center of the four sides of the metal patch 3. This arrangement achieves a lower resonant frequency. Furthermore, by placing a microswitch 7 between the metal patch 3 and the patch resistors 4, the electrical connection between different numbers of patch resistors 4 and the metal patch 3 can be controlled, achieving graded control of the patch antenna gain.

[0066] This embodiment also provides an application of the above-mentioned gain-adjustable patch antenna based on resistance loading and switch control in human body sensors of smart home products such as smart lights.

[0067] Example 5

[0068] This embodiment provides a gain-adjustable patch antenna based on resistor loading and switch controllability. Please refer to [link to relevant documentation]. Figure 6 The structure of this patch antenna is basically the same as that of Embodiment 1, including a metal ground plane 1, a dielectric layer 2 and a metal patch 3 stacked in sequence. The metal patch 3 is connected to a patch resistor 4 through a micro switch 7. The patch resistor 4 is also connected to a metal probe 5. One end of the metal probe 5 is connected to the patch resistor 4, and the other end passes through the dielectric layer 2 and is connected to the metal patch 3, so that the patch resistor 4 is connected to the metal ground plane 1 through the metal probe 5.

[0069] Unlike Embodiment 1, in this embodiment, the dielectric layer 2 uses an FR4 dielectric substrate, and the metal ground plane 1, dielectric layer 2, and metal patch 3 all adopt circular or elliptical structures. There is one patch resistor 4, and correspondingly, there is also one microswitch 7. As shown in the figure, in this embodiment, the cross-sectional shape of the metal ground plane 1, dielectric layer 2, and metal patch 3 is circular, and the patch resistor 4 is connected to the edge of the metal patch 3 via the microswitch 7. By applying different resistance values ​​to the patch resistor 4, efficiency is reduced and gain is controlled. Simultaneously, by controlling the on / off state of the microswitch 7, the electrical connection between the metal patch 3 and the patch resistor 4 is controlled, thereby further realizing gain adjustment of the patch antenna.

[0070] Alternatively, when the cross-sectional shape of the metal ground plane 1, dielectric layer 2, and metal patch 3 is elliptical, the patch resistor 4 is connected to the center line of the elliptical metal patch 3 via a microswitch 7. This embodiment of the patch antenna, by employing a circular or elliptical structure, demonstrates that patch antennas of different shapes can achieve gain adjustment by setting different resistance values ​​for the patch resistor 4 and the microswitch 7.

[0071] Among them, the resistance of the chip resistor 4 is 10-10000Ω, and the metal probe 5 is connected to the side of the chip resistor 4 away from the metal patch 3, so that the metal probe 5 and the metal patch 3 are connected through the chip resistor 4.

[0072] To enable the patch antenna to supply power, the gain-adjustable patch antenna based on resistor loading and switch control provided in this embodiment also includes a feed port 6. The feed port 6 penetrates the dielectric layer 2, with one end connected to the metal ground plane 1 and the other end connected to the metal patch 3.

[0073] This embodiment also provides an application of the above-mentioned gain-adjustable patch antenna based on resistance loading and switch control in human body sensors of smart home products such as smart lights.

[0074] Experimental Example

[0075] 1. The simulated and measured E-plane and H-plane gains of the patch antenna provided in Example 1 were tested under different patch resistor values ​​without the microswitch being set. The test results are as follows: Figure 7 As shown.

[0076] As can be seen from the figure, as the resistance of the patch resistor 4 increases from 200Ω to 510Ω and then to 2000Ω, the main directional gain of the patch antenna continuously increases, and it has an adjustment range of at least 6dB. This proves that the patch antenna provided by the present invention can achieve different gain adjustments by adjusting the resistance of the patch resistor 4 according to different application scenarios, thereby achieving different ranges of recognition effects. This antenna is suitable for human body sensors and prevents the occurrence of false triggering problems.

[0077] 2. The measured S11 reflection coefficient of the patch antenna provided in Example 1 as a function of frequency was tested without the microswitch being set. The test results are as follows: Figure 8 As shown.

[0078] As can be seen from the figure, when different values ​​of patch resistor 4 are used, the working bandwidth of the antenna continuously increases as the resistance of patch resistor 4 decreases.

[0079] 3. Simulate the E-plane and H-plane gain curves of the multi-stage gain-adjustable patch antenna based on resistor loading and switch control provided in Example 1 above as a function of the number of microswitches turned on. The test results are as follows: Figure 9 , Figure 10 As shown.

[0080] As shown in the figure, as the number of microswitches 7 turned on gradually increases, the gain of the patch antenna decreases step by step, with the gain adjustment range changing from 3.7dB to -4.9dB. This very large gain adjustment range can meet the gain variation requirements of various application scenarios. The figure also shows that as the number of microswitches turned on changes, the radiation direction and radiation pattern shape of the resistor-loaded patch do not change significantly, indicating very stable properties.

[0081] In summary, the gain-adjustable patch antenna based on resistor loading provided in this application adjusts the radiation efficiency of the patch antenna by applying resistors 4 of different values ​​and microswitches 7. This allows for gain control of the patch antenna, thereby adjusting the antenna's recognition range according to the actual product's recognition distance requirements. Furthermore, the patch antenna provided in this application reduces the antenna's quality factor by applying resistor loading, thereby increasing the patch antenna's bandwidth and resulting in a wider actual operating frequency band and more stable operation.

[0082] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A gain-adjustable patch antenna based on resistive loading and switch controllability, characterized in that, The device comprises a metal ground plane, a dielectric layer, and metal patches stacked sequentially. Each metal patch is connected to at least one surface-mount resistor via a microswitch. The metal ground plane is connected to the surface-mount resistor via a metal probe. The cross-sectional shape of the metal patch is rectangular, and there are four surface-mount resistors, each connected to one of the four corners of the metal patch via a microswitch. Alternatively, when the cross-sectional shape of the metal patch is rectangular, there is one surface-mount resistor connected to the center of one side of the metal patch via a microswitch. Alternatively, when the cross-sectional shape of the metal patch is rectangular, there are two surface mount resistors, each connected to opposite sides of the metal patch via a microswitch; or when the cross-sectional shape of the metal patch is rectangular, there are four surface mount resistors, each connected to the center of one of the four sides of the metal patch via a microswitch; or when the cross-sectional shape of the metal patch is circular or elliptical, there is one surface mount resistor, connected to the centerline of the metal patch via a microswitch. It also includes a power supply port that penetrates the dielectric layer, with one end connected to the metal floor and the other end connected to the metal patch.

2. The gain-adjustable patch antenna based on resistor loading and switch controllable according to claim 1, characterized in that, The dielectric layer is an air dielectric layer or a dielectric substrate.

3. The gain-adjustable patch antenna based on resistance loading and switch controllable according to claim 2, characterized in that, The metal probe is connected to the side of the chip resistor away from the metal chip; the resistance of the chip resistor is 10-10000Ω.

4. The application of a gain-adjustable patch antenna based on resistance loading and switch controllability as described in any one of claims 1-3 in a human body sensor.

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