An antenna for reducing SAR and cost

Abstract

The present invention discloses an antenna for reducing SAR and cost, which is applicable to various types of antennas and can effectively reduce the SAR value and product cost. The antenna part is divided into three branches. The first branch is the trace led out from the antenna feeding point to form the antenna main body. The second branch is the parasitic unit. The third branch is the Sensor trace, which is connected to the Sensor chip. Through software control, it can not only reduce the SAR value, but also couple with the first part of the trace to generate low, medium, high, and ultra-high frequency resonances, so that the antenna reaches the corresponding efficiency. While reducing the SAR, the present invention can not use the low-frequency tuning switch, so that while the antenna covers all current NR and LTE frequency bands and does not lose the basic functions of the antenna, the product cost can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the field of antennas, and specifically to an antenna for reducing SAR and cost. Background Art

[0002] With the continuous development of communication products, people increasingly pay attention to the health level during product use, and at the same time, the competition among various manufacturers is becoming more and more intense. At present, most mobile products rely on SAR Sensors to reduce the SAR value to ensure people's health. Full-band coverage is achieved through various antenna tuning switches, and some products even have to use multiple switches, resulting in an increase in product cost and a decline in product competitiveness. With the further development of 5G technology, higher-speed wireless transmission is about to enter people's lives. Some users are even using wireless routers to replace traditional wired fiber-optic networks. Therefore, it is particularly important to design an antenna that can meet people's requirements, reduce costs, lower prices, and increase product competitiveness.

[0003] The commonly used LTE frequencies in the current global mobile network are 600 MHz - 960 MHz, 1710 MHz - 2690 MHz, and the NR frequencies are 3300 MHz - 4200 MHz, 4400 MHz - 5000 MHz. Traditional antennas generally separate the ultra-high frequency, that is, the 3300 MHz - 4200 MHz band, for separate antenna design, and the Sensor circuit and antenna tuning switches are also reused. Therefore, the cost pressure on the antennas of communication products comes at any time. Considering health aspects, currently, SAR (Specific Absorption Rate), that is, the ratio of human body's absorption of radiation, is used worldwide to require communication devices with emission functions to meet certain standards before they can be marketed. The use of multiple antenna tuning switches and SAR Sensor chips brings greater cost pressure to the products. The present invention designs an antenna that can save antenna costs and reduce SAR, which can significantly improve the problem of excessively high current antenna costs. Summary of the Invention

[0004] The purpose of the present invention is to provide an antenna for reducing SAR and cost, so as to solve the problems raised in the above background art, and it has the advantages of being able to cover all LTE and NR bands, saving antenna costs, and reducing SAR.

[0005] To achieve the above purpose, the present invention provides the following technical solution: An antenna for reducing SAR and cost, including a PCB board and an antenna part. The PCB board includes a clearance area and a non-clearance area, and the non-clearance area is covered with a metal layer. The antenna is above the plane and on the side of the PCB board.

[0006] The antenna includes a first branch, a second branch, a third branch, a feeding point, a Sensor feeding point, an antenna matching circuit, a Sensor matching circuit, as well as a first short circuit point, a second short circuit point and a Sensor chip.

[0007] The first branch is in an inverted F shape and connects the feeding point and the first short circuit point; the second branch is a first parasitic unit and connects the second short circuit point; the third branch is a Sensor trace, forming a Sensor antenna, surrounding the first branch and connecting the Sensor feeding point to form a second parasitic unit; the first branch, the second branch, and the third branch are all located in the clearance area, and the antenna matching circuit, the Sensor matching circuit, and the Sensor chip are all located in the non-clearance area.

[0008] The feeding point, the first short circuit point, the second short circuit point, and the Sensor feeding point are located in the clearance area and are parallel to the short side of the PCB and arranged side by side. The second short circuit point is located at the edge of the long side of the PCB and is connected to the second branch to form a first parasitic unit. The feeding point is 1.5 mm inside the second short circuit point and is connected to the first branch and the antenna matching circuit; the first short circuit point is 1.5 mm inside the feeding point and is connected to the first branch; the feeding point, the first short circuit point, the antenna matching circuit, and the first branch constitute the antenna body. The Sensor feeding point is 5 mm inside the first short circuit point, one end is connected to the Sensor matching circuit, and the other end is connected to the third branch to form a second parasitic unit. The other end of the Sensor matching circuit is connected to the Sensor chip.

[0009] The third branch, the Sensor feeding point, the Sensor matching circuit, and the Sensor chip are connected to form a SAR reduction antenna. When a human body approaches the sensor, the Sensor chip receives the sensor signal and reduces the transmission power of the terminal, thereby achieving the purpose of SAR reduction.

[0010] By adopting the above technical solution, the requirements of all LTE and NR frequency bands can be met, and at the same time, the requirement of SAR reduction can also be achieved. No antenna tuning switch is used in the antenna design, which can effectively reduce the antenna cost and improve the market competitiveness of the mobile phone. The third branch is connected to the Sensor feeding point, the Sensor matching circuit, and the Sensor chip to form a SAR reduction antenna. When a human body approaches the sensor, the Sensor chip receives the sensor signal and reduces the transmission power of the terminal, thereby achieving the purpose of SAR reduction.

[0011] Preferably, the first branch generates multiple couplings and resonates effectively. The first branch, the second branch, and the third branch are located on one side of the long side of the PCB board, within the clearance area, where a part is parallel to the plane of the PCB board and a part is perpendicular to the plane of the PCB board.

[0012] Preferably, the maximum distance between the antenna body and the PCB board is 3 mm, and the width of the clearance area is 5 - 8 mm.

[0013] Preferably, the length of the PCB board is 180 mm, the width is 72 mm, the length of the clearance area is 72 mm, the width is 5 mm, the length of the non - clearance area is 175 mm, the width is 72 mm, and the long side of the clearance area is parallel to the wide side of the PCB board.

[0014] Preferably, the first branch is located at the center of the projected area of the clearance area, with an overall width of 5 mm and a length of 160 mm. The second branch is located on one side of the projected area of the clearance area, in an inverted "L" shape, close to the edge of the PCB board, with a line width of 2 mm and an overall length of 8 mm after expansion. The third branch wraps the first branch, in a "C" shape, with a line width of 1 mm, and the outermost line is perpendicular to the PCB trace, located on the "TOP" surface of the whole machine. The distance between all lines and the first branch is 0.5 mm.

[0015] Preferably, the feeding point, the first short - circuit point, the second short - circuit point, and the Sensor feeding point are located within the clearance area and are arranged starting from the edge of the PCB board in sequence as the second short - circuit point, the feeding point, the first short - circuit point, the Sensor feeding point. The distance between the second short - circuit point and the edge of the PCB board is 2 mm, and the feeding point and the first short - circuit point are arranged at intervals of 1.5 mm in sequence. The distance between the Sensor feeding point and the second short - circuit point is 5 mm.

[0016] Preferably, the antenna matching circuit is connected to the feeding point through a microstrip line with an impedance of 50 Ω. The Sensor chip is connected to the Sensor matching circuit, and the other end of the Sensor matching circuit is connected to the Sensor feeding point.

[0017] Preferably, the antenna body generates resonance at a low frequency of 750 MHz - 960 MHz, and simultaneously generates effective resonance at 1900 MHz - 2170 MHz, 2500 MHz - 2690 MHz, and 3800 MHz - 4200 MHz; the second branch and the second short - circuit point form a first parasitic unit, which couples with the antenna body to generate effective resonance at 2300 MHz - 2500 MHz and 4400 MHz - 5000 MHz; the third branch, the Sensor feed point, and the Sensor matching circuit form a second parasitic unit, which couples with the antenna body to generate effective resonance at 600 MHz - 750 MHz, 1700 MHz - 1900 MHz, and 3300 MHz - 3800 MHz; all the above - mentioned effective resonances together constitute low - frequency, medium - frequency, high - frequency, and ultra - high - frequency resonances, covering all NR and LTE frequency bands.

[0018] Preferably, the Sensor matching circuit is an L - type matching. The shunt is a 33PF capacitor, and the series is an inductor. The capacitor is used to isolate the Sensor chip from the ground to ensure the function of the Sensor chip, and the inductor is used to tune the trace. Different areas and shapes of the third branch can tune each resonance coupled with the first branch to ensure it is an effective resonance.

[0019] As a further solution of the present invention: the trace of the third branch wraps the first branch.

[0020] By adopting the above - mentioned technical solution, the trace of the third branch wraps the first branch to ensure that the Sensor function can be used. When holding the antenna, the third branch where the Sensor is located directly reduces the transmit power of the product, playing a role in reducing SAR. Before mass - producing the product, it is necessary to conduct an SAR test on the antenna to determine the value of the reduced power, and write it into the Sensor through software to avoid excessive power reduction that may affect the call effect.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. It can meet the requirements of all LTE and NR frequency bands, and at the same time can also meet the requirement of reducing SAR. No antenna tuning switch is used in the antenna design, which can effectively reduce the antenna cost and improve the market competitiveness of the mobile phone. The third branch, the Sensor feed point, the Sensor matching circuit, and the Sensor chip are connected to form an SAR - reducing antenna. When a human body approaches the sensor, the Sensor chip receives the sensor signal and reduces the transmit power of the terminal, thereby achieving the purpose of reducing SAR.

[0023] 2. While reducing the SAR, the present invention can avoid using low-frequency tuning switches. As a result, while enabling the antenna to cover all current NR and LTE frequency bands without losing the basic functions of the antenna, the product cost can be effectively reduced. If the antenna of a product contains two or more antenna tuning switches, the present invention can even save all the antenna tuning switches and can significantly reduce the product cost, covering all current NR and LTE frequency bands. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG. Figure 1 is a schematic structural diagram of an antenna for reducing SAR and cost in an embodiment of the present invention;

[0025] FIG. Figure 2 is the Figure 1 front view;

[0026] FIG. Figure 3 is the Figure 1 side view;

[0027] FIG. Figure 4 is the Figure 1 top view;

[0028] FIG. Figure 5 is the Figure 1 bottom view;

[0029] FIG. Figure 6 is the antenna matching circuit diagram;

[0030] FIG. Figure 7 is the Sensor matching circuit diagram;

[0031] FIG. Figure 8 is the return loss diagram of an antenna for reducing SAR and cost in an embodiment of the present invention;

[0032] FIG. Figure 9 is the comparison of the efficiency of an antenna for reducing SAR and cost in an embodiment of the present invention with the efficiency of an antenna with a tuning switch in the same environment.

[0033] In the figures: 1, non-clearance area; 2, clearance area; 21, first branch; 22, second branch; 23, third branch; 31, first short circuit point; 32, feeding point; 33, second short circuit point; 34, Sensor feeding point; 41, antenna matching circuit; 42, Sensor matching circuit; 43, Sensor chip. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] In the embodiments of the present invention,

[0036] An antenna for reducing SAR and cost includes a PCB board and an antenna part. The PCB board includes a clearance area and a non-clearance area. The non-clearance area is covered with a metal layer. The antenna is above and on the side of the PCB board plane.

[0037] The antenna includes a first branch, a second branch, a third branch, a feeding point, a Sensor feeding point, an antenna matching circuit, a Sensor matching circuit, a first short circuit point, a second short circuit point, and a Sensor chip.

[0038] The first branch is in an inverted F shape and connects the feeding point and the first short circuit point; the second branch is a first parasitic unit and connects the second short circuit point; the third branch is a Sensor trace, forming a Sensor antenna, surrounding the first branch and connecting the Sensor feeding point as a second parasitic unit; the first branch, the second branch, and the third branch are all located in the clearance area, and the antenna matching circuit, the Sensor matching circuit, and the Sensor chip are all located in the non-clearance area.

[0039] The feeding point, the first short circuit point, the second short circuit point, and the Sensor feeding point are located in the clearance area and are parallel to the short side of the PCB and arranged side by side. The second short circuit point is located at the edge of the long side of the PCB board and is connected to the second branch to form a first parasitic unit. The feeding point is 1.5 mm inside the second short circuit point and is connected to the first branch and the antenna matching circuit; the first short circuit point is 1.5 mm inside the feeding point and is connected to the first branch; the feeding point, the first short circuit point, the antenna matching circuit, and the first branch constitute the antenna body. The Sensor feeding point is 5 mm inside the first short circuit point, one end is connected to the Sensor matching circuit, and the other end is connected to the third branch to form a second parasitic unit. The other end of the Sensor matching circuit is connected to the Sensor chip.

[0040] The third branch, the Sensor feed point, the Sensor matching circuit and the Sensor chip are connected to form a SAR reduction antenna. When a human body approaches the sensor, the Sensor chip receives a sensor signal and reduces the transmission power of the terminal, thereby achieving the purpose of SAR reduction.

[0041] The first branch generates multiple couplings and resonates effectively. The first branch, the second branch, and the third branch are located on one long side of the PCB board. In the clearance area, a part of them is parallel to the plane of the PCB board and a part is perpendicular to the plane of the PCB board.

[0042] The maximum distance between the antenna body and the PCB board is 3 mm, and the width of the clearance area is 5 - 8 mm. The minimum requirement for the width of the clearance area on the PCB board is 5 mm. When it is higher than 5 mm, the average gain of the antenna will increase.

[0043] The length of the PCB board is 180 mm and the width is 72 mm. The length of the clearance area is 72 mm and the width is 5 mm. The length of the non - clearance area is 175 mm and the width is 72 mm. The long side of the clearance area is parallel to the wide side of the PCB board.

[0044] The first branch is located at the center of the projected area of the clearance area. Its overall width is 5 mm and the length is 160 mm. The second branch is located on one side of the projected area of the clearance area, in an inverted "L" shape, close to the edge of the PCB board. The line width is 2 mm, and the overall length after expansion is 8 mm. The third branch wraps the first branch, in a "C" shape, with a line width of 1 mm. The outermost line is perpendicular to the PCB board trace and is located on the "TOP" surface of the whole machine. The distance between all lines and the first branch is 0.5 mm.

[0045] The feed point, the first short - circuit point, the second short - circuit point, and the Sensor feed point are located in the clearance area and are arranged starting from the edge of the PCB board in sequence as the second short - circuit point, the feed point, the first short - circuit point, and the Sensor feed point. The distance between the second short - circuit point and the edge of the PCB board is 2 mm. The feed point and the first short - circuit point are arranged at intervals of 1.5 mm in sequence. The distance between the Sensor feed point and the second short - circuit point is 5 mm.

[0046] The antenna matching circuit is connected to the feed point through a microstrip line with an impedance of 50 Ω. The Sensor chip is connected to the Sensor matching circuit, and the other end of the Sensor matching circuit is connected to the Sensor feed point.

[0047] The antenna body generates resonance at a low frequency of 750 MHz - 960 MHz, and simultaneously generates effective resonance at 1900 MHz - 2170 MHz, 2500 MHz - 2690 MHz, and 3800 MHz - 4200 MHz; the second branch and the second short - circuit point form a first parasitic unit, which couples with the antenna body to generate effective resonance at 2300 MHz - 2500 MHz and 4400 MHz - 5000 MHz; the third branch, the Sensor feed point, and the Sensor matching circuit form a second parasitic unit, which couples with the antenna body to generate effective resonance at 600 MHz - 750 MHz, 1700 MHz - 1900 MHz, and 3300 MHz - 3800 MHz; all the above - mentioned effective resonances together constitute low - frequency, medium - frequency, high - frequency, and ultra - high - frequency resonances, covering all NR and LTE frequency bands.

[0048] The Sensor matching circuit is an L - type matching. The shunt is a 33PF capacitor, and the series is an inductor. The capacitor is used to isolate the Sensor chip from the ground to ensure the function of the Sensor chip, and the inductor is used to tune the trace. Different areas and shapes of the third branch can tune each resonance coupled with the first branch to ensure it is an effective resonance.

[0049] The trace of the third branch wraps the first branch.

[0050] The third branch is the Sensor trace. The first branch 21 is located in the center of the clearance area 2, and the trace is in an inverted F - shape; the second branch 22 is in an L - shape, and the trace is located at the right - most side of the clearance area 2, in an L - shape, and part of the trace is on the side perpendicular to the PCB; the third branch 23 is located on the left side of the clearance area 2, and is overall in a C - shape, wrapping the first branch 21, and the outermost end is close to the end of the second branch 22, and part of the trace is on the long side of the clearance area 2, perpendicular to the area of the PCB.

[0051] The lengths of all the traces of the first branch 21, the second branch 22, and the third branch 23 are 78 mm, and the height of the side of the clearance area of 3 mm is used for tracing; the width is 8 mm, and the height of the top of the mobile phone of 3 mm is used for tracing. So after the antenna is unfolded, the overall length is 78 mm and the width is 8 mm. Among them, the length of the second branch 22 is 4 mm and the width is 4 mm, the longest side length of the third branch 23 is 76 mm, the short side length is 51 mm, and the trace width is 1 mm; the second branch 22 and the third branch 23 form a ring around the clearance area 2, embedding the first branch 21 inside, with a distance of 1 mm. The first branch 21 is in an inverted F - shape, and the longest side is 2 mm away from both the second branch 22 and the third branch 23, and the widest trace inside is 2 mm, 4 mm, 1.5 mm, and 2 mm away from the four sides.

[0052] The feeding point 32, the first short - circuit point 31, and the second short - circuit point 33 are of the same size, all being 2mm×3mm. The second short - circuit point is located within the clearance area 2, 2mm away from the right - most edge of both the non - clearance area 1 and the clearance area 2. The feeding point 32 and the first short - circuit point 31 are arranged successively 1.5mm apart towards the left. The Sensor feeding point 34 is 5mm away from the first short - circuit point 31 and is arranged parallel to the left within the clearance area 2. The antenna matching circuit 41 is located within the non - clearance area 1 and is connected to the feeding point 32, and the impedance of the connecting microstrip line is 50Ω; the Sensor feeding point 42 is located within the non - clearance area 1, one end is connected to the Sensor feeding point with a 50Ω microstrip line, and the other end is connected to the Sensor chip 43 also within the non - clearance area 1. The length of all microstrip lines is 8mm.

[0053] When the antenna is working, the capacitance in the Sensor matching circuit is 33PF, which is used for the isolation between the Sensor chip and the ground, and the inductance is 8.2NH, which is used for tuning the third branch 23. Through the coupling of the above - mentioned parts, the antenna frequency band operates at low frequencies of 600MHz - 960MHz, intermediate frequencies of 1710MHz - 2170MHz, high frequencies of 2300MHz - 2690MHz, and ultra - high frequencies of 3300MHz - 5000MHz. Among them, the first branch 21 controls the effective resonance at 750MHz - 960MHz, 1900MHz - 2170MHz, 2500MHz - 2690MHz, 3800MHz - 4200MHz; the second branch 22 controls the effective resonance at 2300MHz - 2500MHz, 4400MHz - 5000MHz; the third branch 23 controls the effective resonance at 600MHz - 750MHz, 1700MHz - 1900MHz, 3300MHz - 3800MHz. All the above resonances are generated by the coupling of each branch under the cooperation of the antenna matching circuit 41 and the Sensor matching circuit 42, and each branch cannot generate an effective resonance alone. The third branch 33 also acts as a sensor through the Sensor chip 43. When a human body is 5mm close to the mobile phone, the Sensor chip 43 detects the approach of the human body and will actively reduce the power to control the SAR value within the required range. The above is the reason for the final effect of reducing SAR and cost in the present invention.

[0054] In some examples, the antenna also includes a matching circuit for optimizing the ground feeding point, which can achieve the purpose of increasing the antenna bandwidth. In this example, the additional matching circuit is connected to the ground of the mobile phone after the two short - circuit points included in the present invention.

[0055] In this example, in the antenna matching circuit 41, the device of C1 is 12 nH, the device of L1 is 5 pF, the device of C2 is 0.75 pF, and the device of L2 is 2.2 nH. In the Sensor matching circuit 42, the device of L is 8.2 nH and the device of C is 33 pF. Replacing different devices will cause different changes in the antenna resonance. In some other examples, the matching circuit needs to be re-tuned.

[0056] Appendix Figure 8 - Appendix Figure 9 It shows that based on the designed low-frequency coverage, the frequency is 600 MHz - 960 MHz, and the average efficiency can reach -6 dBm; based on the designed medium / high-frequency coverage, the frequency is 1710 MHz - 2690 MHz, and the average efficiency can reach -5 dBm; based on the designed high-frequency coverage, the frequency is 3300 MHz - 5000 MHz, and the average efficiency can reach -5.5 dBm. Compared with the antenna with an antenna tuning switch, the average efficiency is basically the same. Based on the current mobile phone antenna standard, it can already meet the full-band coverage of LTE and NR bands on mobile phones.

[0057] In other general examples, the third branch in this example is generally not designed. The Sensor is generally directly connected to the antenna feed point. This can also make the antenna reach the antenna efficiency in this example, but 1 - 2 more antenna tuning switches are needed than in this example to switch between low frequency and medium frequency. In this example, the additional third branch is specially designed for the Sensor circuit. It can not only function as a Sensor but also couple with other antenna parts to generate a series of effective resonances that can replace the switch switching. The additional third branch does not increase the antenna cost, and the saved antenna tuning switches will save a large amount of cost for the product.

[0058] The disadvantage of this example is that a larger PCB board clearance area is required. For some PCB boards with too small sizes, when the clearance area requirement cannot be met, the antenna efficiency will be somewhat discounted when using this example.

[0059] Since the antenna circuit in the present invention is relatively simple and the Sensor branch has strong adjustability, there will be various changes in the design of the present invention, which can meet the requirements of the antenna environment and the device placement position of different mobile phones or tablets, and has a wide application prospect.

[0060] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. An antenna for reducing SAR and cost, comprising a PCB board and an antenna part, wherein the PCB board comprises a clearance area and a non-clearance area, wherein the non-clearance area is covered with a metal layer, and the antenna is directly above and on the side of the plane of the PCB board, characterized in that: The antenna includes a first branch, a second branch, a third branch, a feeding point, a sensor feeding point, an antenna matching circuit, a sensor matching circuit, a first short-circuit point, a second short-circuit point and a sensor chip. The first branch is an inverted F-shape, connecting the feed point and the first short-circuit point; the second branch is a first parasitic unit, connecting the second short-circuit point; the third branch is a sensor routing, forming a sensor antenna, surrounding the first branch, and connecting the sensor feed point to form a second parasitic unit; the first branch, the second branch, and the third branch are all located in the clear area, and the antenna matching circuit, the sensor matching circuit, and the sensor chip are all located in the non-clear area. The feeding point, the first short-circuit point, the second short-circuit point, and the sensor feeding point are located in the clearance area and are parallel to the short side of the PCB and placed side by side. The second short-circuit point is located at the edge of the long side of the PCB board and is connected to the second branch to form a first parasitic unit. The feeding point is 1.5 mm inside the second short-circuit point and is connected to the first branch and the antenna matching circuit; the first short-circuit point is 1.5 mm inside the feeding point and is connected to the first branch; the feeding point, the first short-circuit point, the antenna matching circuit, and the first branch constitute the antenna body. The sensor feeding point is located 5 mm inside the first short-circuit point, one end is connected to the sensor matching circuit, and the other end is connected to the third branch to form a second parasitic unit. The other end of the sensor matching circuit is connected to the sensor chip. The third branch, the sensor feed point, the sensor matching circuit and the sensor chip are connected to form a SAR reduction antenna. When a human body approaches the sensor, the sensor chip receives the sensor signal and reduces the transmission power for the terminal, thereby achieving the purpose of reducing SAR. The first branch is located in the center of the projection area of ​​the clearance area, with an overall width of 5mm and a length of 160mm. The second branch is located on one side of the projection area of ​​the clearance area, in an inverted "L" shape, close to the edge of the PCB board, with a line width of 2mm and an overall length of 8mm after unfolding. The third branch wraps the first branch and is in a "C" shape. The line width is 1mm, the outermost line is perpendicular to the PCB board routing, located on the "TOP" surface of the whole machine, all lines are 0.5mm away from the first branch, the feeding point, the first short-circuit point, the second short-circuit point, and the sensor feeding point are located in the clearance area, starting from the edge of the PCB board, arranged in order of the second short-circuit point, the feeding point, the first short-circuit point, the sensor feeding point, and the second short-circuit point are 2mm away from the edge of the PCB board, the feeding point, the first short-circuit point are arranged in sequence at an interval of 1.5mm, the sensor feeding point is 5mm away from the second short-circuit point, and the antenna The line body generates a low-frequency resonance of 750MHz-960MHz, and simultaneously generates effective resonances of 1900MHz-2170MHz, 2500MHz-2690MHz, and 3800MHz-4200MHz; the second branch and the second short-circuit point constitute a first parasitic unit, which couples with the antenna body to generate effective resonances of 2300MHz-2500MHz and 4400MHz-5000MHz; the third branch and the sensor feeding point, and the sensor matching circuit constitute a second parasitic unit, which couples with the antenna body to generate effective resonances of 600MHz-750MHz, 1700MHz-2170MHz, 2500MHz-2690MHz, and 3800MHz-4200MHz. MHz-1900MHz, 3300MHz-3800MHz effective resonance; all the above effective resonances together constitute low-frequency, medium-frequency, high-frequency and ultra-high-frequency resonances, covering all NR and LTE frequency bands. The Sensor matching circuit is an L-type matching, with a 33PF capacitor in parallel and an inductor in series. The capacitor is used to isolate the Sensor chip from the ground to ensure the function of the Sensor chip. The inductor is used to tune the wiring. The difference in area and shape of the third branch can tune the various resonances coupled with the first branch to ensure that it is an effective resonance. The third branch 33 also acts as a sensor through the Sensor chip 43.

2. The antenna for reducing SAR and cost according to claim 1, characterized in that: The first branch coupling generates multiple couplings and effective resonances. The first branch, the second branch, and the third branch are located on one side of the long side of the PCB board, within the clearance area, a portion of which is parallel to the plane of the PCB board, and a portion of which is perpendicular to the plane of the PCB board.

3. The antenna for reducing SAR and cost according to claim 1, characterized in that: The maximum distance between the antenna body and the PCB board is 3 mm, and the width of the clearance area is 5-8 mm.

4. The antenna for reducing SAR and cost according to claim 1, characterized in that: The PCB board has a length of 180 mm and a width of 72 mm, the clearance area has a length of 72 mm and a width of 5 mm, the non-clearance area has a length of 175 mm and a width of 72 mm, and the long side of the clearance area is parallel to the wide side of the PCB board.

5. The antenna for reducing SAR and cost according to claim 1, characterized in that: The antenna matching circuit is connected to the feeding point via a microstrip line with an impedance of 50Ω, the sensor chip is connected to the sensor matching circuit, and the other end of the sensor matching circuit is connected to the sensor feeding point.

6. The antenna for reducing SAR and cost according to claim 1, characterized in that: The third branch line wraps around the first branch.

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