CN114156633B - Low SAR antenna device and electronic equipment - Google Patents

Abstract

The embodiment of the application provides a low SAR antenna device and electronic equipment, this low SAR antenna device is through setting up at least one auxiliary radiation unit, auxiliary radiation unit's one end links to each other with main radiation unit, auxiliary radiation unit's the other end links to each other with the feed source, the feed source is main radiation unit and auxiliary radiation unit feed respectively, and auxiliary radiation unit does not produce the resonance on main radiation unit's operating frequency, can reduce low SAR antenna device in the SAR value under the state apart from human 0mm, do not change low SAR antenna device radiation performance under free space, thereby can promote low SAR antenna device's radiating effect.

Description

Low SAR Antenna Device and Electronic Equipment

technical field

The embodiments of the present application relate to the field of antenna technologies, and in particular, to a low SAR antenna device and an electronic device.

Background technique

With the continuous development of communication technology, more and more attention has been paid to the wireless performance of electronic devices such as mobile phones. Therefore, the application of antenna technology in electronic devices is more and more extensive, and the demand is also higher and higher. However, when the body part is close to the antenna, the antenna will radiate to the body.

The Specific Absorption Rate (SAR) can be used to indicate the magnitude of the antenna's radiation to the human body. At present, the SAR value of the human body close to the electronic device at a distance of 5mm or 0mm is generally used to measure the radiation of the antenna to the human body. The SAR value in the 0mm state is higher than the SAR value in the 5mm state, and the radiation to the human body is greater. Generally, when the transmit power of the antenna is high, the radiation to the human body is large, and when the transmit power of the antenna is low, the radiation to the human body is small, but at the same time, the signal is poor. In the related art, in order to reduce the SAR value of the antenna, the radiation performance of the antenna in the free space will also be changed. Therefore, how to reduce the SAR value of the antenna at a distance of 0 mm from the human body without changing the radiation performance of the antenna in the free space is required in the field of antennas. A very important problem to be solved.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a low SAR antenna device and electronic equipment, which can reduce the SAR value of the low SAR antenna device at a distance of 0 mm from the human body, without changing the radiation performance of the low SAR antenna device in free space, thereby enabling Improve the radiation effect of low SAR antenna devices.

In a first aspect, an embodiment of the present application provides a low SAR antenna device, the low SAR antenna device is applied to electronic equipment, and the low SAR antenna device at least includes: at least one main radiating unit and at least one feed source; and also includes: at least A secondary radiating unit, one end of the secondary radiating unit is connected to the main radiating unit, and the other end of the secondary radiating unit is connected to the feed source; the feed sources are the main radiating unit and the secondary radiating unit respectively The radiating element is fed, and the secondary radiating element does not resonate at the operating frequency of the main radiating element.

In the low SAR antenna device provided by the embodiment of the present application, the low SAR antenna device is provided with at least one secondary radiation unit, one end of the secondary radiation unit is connected to the main radiation unit, and the other end of the secondary radiation unit is connected to the feed source, so that at least one end of the secondary radiation unit is connected to the feeder. A feed source feeds at least one main radiating unit and a secondary radiating unit respectively. In addition, since the secondary radiating unit does not resonate at the working frequency of the main radiating unit, in this way, the low SAR antenna device is in a free space state, and the main radiating unit works. In the resonant state, the resonant frequency of the secondary radiating element is far away from the working frequency of the main radiating element, that is, the secondary radiating element works in a non-resonant state. The radiation energy of the radiation unit accounts for a small proportion, so the influence of the secondary radiation unit on the performance of the main radiation unit is extremely small. When the main radiation unit is close to the human body, part of the energy of the main radiation unit will be reflected back by the human body. Since part of the energy of the main radiation unit is reflected and part of the energy is absorbed by the human body, the proportion of the radiation energy of the main radiation unit will be greatly reduced, and the secondary radiation will be greatly reduced. The proportion of radiation energy of the unit is relatively greatly enhanced, so the 0mm SAR value of the main radiation unit can be reduced. Therefore, the embodiments of the present application can reduce the SAR value of the low SAR antenna device at a distance of 0 mm from the human body without changing the radiation performance of the low SAR antenna device in free space, thereby improving the radiation effect of the low SAR antenna device.

In a possible implementation manner, the resonant frequency of the secondary radiating unit is 1 to 3 times the resonant frequency of the main radiating unit. If the resonant frequency of the secondary radiation unit is too small, it will affect the free space state of the low SAR antenna device. When the resonant frequency of the secondary radiation unit is too large, the radiation capacity of the secondary radiation unit is small, resulting in the radiation effect of the low SAR antenna device. poor. When the resonant frequency of the secondary radiating element is 1 to 3 times the resonant frequency of the main radiating element, it will not affect the free space state of the low SAR antenna device, but also ensure the radiation effect of the low SAR antenna device.

In a possible implementation manner, the method further includes: a first transmission line and a second transmission line; the number of the secondary radiation units is one; one end of the first transmission line is connected to the main radiation unit, and the first transmission line The other end of the second transmission line is connected to the secondary radiation unit; one end of the second transmission line is connected to the secondary radiation unit, and the other end of the second transmission line is connected to the feeder. When the number of secondary radiating units is one, it can ensure that one end of the secondary radiating unit is connected to the main radiating unit, and the other end of the secondary radiating unit is connected to the feeder, so as to ensure that the feeder can be the main radiating unit and the secondary radiating unit respectively series feed.

In a possible implementation manner, the length of the first transmission line is between 1/8 wavelength and 1 times the wavelength of the first transmission line. When the main radiation unit is close to the human body, the proportion of the radiation energy of the main radiation unit is greatly weakened. At this time, the secondary radiation unit is located near the maximum point of the standing wave current of the first transmission line and the second transmission line, which can greatly enhance the radiation capacity of the secondary radiation unit. . The length of the first transmission line is between 1/8 wavelength and 1 times the wavelength of the first transmission line, which can ensure that the secondary radiation unit is located near the maximum point of the standing wave current of the first transmission line and the second transmission line.

In a possible implementation manner, the length of the first transmission line is between 1/8 wavelength and 1/2 wavelength of the first transmission line. The length of the first transmission line is between 1/8 wavelength and 1/2 wavelength of the first transmission line, which can shorten the range when the secondary radiation unit is located near the maximum point of the standing wave current of the first transmission line and the second transmission line, so that it can further Improve the radiation capability of the secondary radiation unit.

In a possible implementation manner, the method further includes: a matching circuit; one end of the matching circuit is connected to the main radiation unit, and the other end of the matching circuit is connected to the first transmission line. By arranging a matching circuit in the low SAR antenna device, the achievable function of the low SAR antenna device can be increased, and the achievable function of the electronic device having the low SAR antenna device can be increased.

In a possible implementation manner, the matching circuit at least includes: any one or more of capacitors, inductors or resistors.

In a possible implementation manner, the method further includes: a third transmission line located between the first transmission line and the second transmission line; the number of the secondary radiation units is two; among the two secondary radiation units One end of one of the two sub-radiation units is connected to the first transmission line, the other end of one of the two sub-radiation units is connected to the third transmission line; the other end of the two sub-radiation units is connected to the third transmission line; One end is connected to the third transmission line, and the other end of the other of the two auxiliary radiation units is connected to the second transmission line.

When the number of sub-radiation units is two, this ensures that the two sub-radiation units are connected in series with each other, one of the two sub-radiation units is connected to the main radiation unit, and the other of the two sub-radiation units is connected to the main radiation unit. The feed sources are connected to ensure that the feed sources can simultaneously feed the main radiating unit and the two secondary radiating units in series.

In a possible implementation manner, the method further includes: a fourth transmission line and a fifth transmission line; the number of the secondary radiation units is two; one end of the fourth transmission line is connected to the main radiation unit, and the fourth transmission line is connected to the main radiation unit. The other end of the transmission line is connected to one end of one of the two secondary radiation units; one end of the fifth transmission line is connected to the other end of one of the two secondary radiation units, and the fifth transmission line is connected to the other end of one of the two secondary radiation units. The other end of the transmission line is connected to the feed source; one end of the other of the two sub-radiating units is connected to the first transmission line, and the other end of the other of the two sub-radiating units is connected to the first transmission line. connected to the second transmission line.

When the number of secondary radiating units is two, this ensures that the two secondary radiating units are connected in parallel with each other, one of the two secondary radiating units is connected to the main radiating unit and the feeder respectively, and one of the two secondary radiating units is connected to the main radiating unit and the feeder respectively. The other one is respectively connected with the main radiating unit and the feeding source, so as to ensure that the feeding source can feed the main radiating unit and the two secondary radiating units respectively at the same time.

In a second aspect, an embodiment of the present application provides an electronic device, the electronic device includes at least a display screen, a rear case, and a middle frame between the display screen and the rear case, and further includes: any of the above The low SAR antenna device; the middle frame is a metal middle frame, and the metal middle frame includes at least a metal frame, and the metal frame forms at least one main radiation unit in the low SAR antenna device.

In the electronic device provided by the embodiment of the present application, the electronic device includes at least a low SAR antenna device, and the low SAR antenna device is provided with at least one secondary radiation unit, one end of the secondary radiation unit is connected to the main radiation unit, and the other side of the secondary radiation unit is connected. One end is connected to the feed source, so that at least one feed source feeds at least one main radiating element and a secondary radiating element respectively. In addition, since the secondary radiating element does not resonate at the working frequency of the main radiating element, in this way, the low SAR antenna device is free to operate. In the space state, when the main radiating element works in the resonant state, the resonant frequency of the secondary radiating element is far away from the operating frequency of the main radiating element, that is, the secondary radiating element works in the non-resonant state. At this time, most of the energy of the low SAR antenna device is Radiated from the main radiation unit, the proportion of the radiant energy of the secondary radiation unit is very small, so the influence of the secondary radiation unit on the performance of the main radiation unit is extremely small. When the main radiation unit is close to the human body, part of the energy of the main radiation unit will be reflected back by the human body. Since part of the energy of the main radiation unit is reflected and part of the energy is absorbed by the human body, the proportion of the radiation energy of the main radiation unit will be greatly reduced, and the secondary radiation will be greatly reduced. The proportion of radiation energy of the unit is relatively greatly enhanced, so the 0mm SAR value of the main radiation unit can be reduced. Therefore, the embodiments of the present application can reduce the SAR value of the low SAR antenna device at a distance of 0 mm from the human body without changing the radiation performance of the low SAR antenna device in free space, thereby improving the radiation effect of the low SAR antenna device.

In a possible implementation manner, the secondary radiation unit in the low SAR antenna device is a metal sheet.

In a possible implementation manner, the metal middle frame further includes: a metal middle plate; the metal frame is arranged around the outer circumference of the metal middle plate; and the secondary radiation unit of the low SAR antenna device is connected to the metal middle plate. The vertical distance between the middle plates is 0.5mm-3mm. In this way, the radiation performance of the secondary radiation unit can be ensured while the secondary radiation unit of the low SAR antenna device is ensured to be suspended in the air.

Description of drawings

FIG. 1 is a schematic structural diagram of an electronic device provided by an embodiment of the present application;

Fig. 2 is the exploded view of Fig. 1;

FIG. 3 is a schematic structural diagram of an electronic device provided by an embodiment of the present application;

4 is a schematic structural diagram of the low SAR antenna device in the electronic device shown in FIG. 3;

5 is a schematic diagram of a partial structure when the antenna device in the prior art is matched with the middle frame;

FIG. 6 is a schematic partial structural diagram of a low SAR antenna device provided in an embodiment of the present application when a middle frame is matched;

7 is a schematic structural diagram of a low SAR antenna device provided by an embodiment of the present application when it is close to a human body;

8 is a schematic diagram of a working state of a low SAR antenna device provided in an embodiment of the present application in a free space state;

9 is a schematic diagram of a working state of a low SAR antenna device provided by an embodiment of the present application when it is close to a human body;

10 is a schematic structural diagram of a low SAR antenna device provided by an embodiment of the present application;

11 is a schematic structural diagram of a low SAR antenna device provided by an embodiment of the present application;

12 is a comparison diagram of a reflection coefficient curve of a low SAR antenna device provided by an embodiment of the application compared to an antenna device in the prior art in a free space state;

13 is a comparison diagram of an antenna efficiency curve of a low SAR antenna device provided by an embodiment of the present application compared to an antenna device in the prior art in a free space state;

14 is a radiation pattern at 2.45 GHz of an antenna device in the prior art in a free space state;

15 is a radiation pattern at 2.45 GHz of the low SAR antenna device provided by an embodiment of the application in a free space state;

16 is a comparison diagram of the reflection coefficient curve of the low SAR antenna device provided by an embodiment of the application compared with the antenna device in the prior art when the human body is 0 mm;

17 is a comparison diagram of the antenna efficiency curve of the low SAR antenna device provided by an embodiment of the application compared to the antenna device in the prior art when the human body is 0 mm;

FIG. 18 is a SAR heat map of the antenna device in the prior art in the state of 0 mm of the human body;

FIG. 19 is a SAR heat map of the low SAR antenna device provided by an embodiment of the present application in a state of 0 mm of the human body.

Description of reference numbers:

100-low SAR antenna device; 110-main radiation unit; 120-feeder;

130-secondary radiation unit; 140-first transmission line; 150-second transmission line;

160-matching circuit; 170-third transmission line; 180-fourth transmission line;

190-fifth transmission line; 200-electronic equipment; 210-display screen;

211-first opening; 220-middle frame; 221-metal middle plate;

222-border; 2221-top border; 2222-bottom border;

2223-left side frame; 2224-right side frame; 230-circuit board;

240-battery; 250-back shell; 251-second opening;

260-front camera module; 270-rear camera module; 300-human body;

310 - Transmission Line.

Detailed ways

The terms used in the embodiments of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application. The following will describe the embodiments of the embodiments of the present application in detail with reference to the accompanying drawings.

The embodiment of the present application provides an electronic device, which may include, but is not limited to, a mobile phone, a tablet computer, a notebook computer, an ultra-mobile personal computer (UMPC), a handheld computer, a walkie-talkie, a netbook, a point of sale (Point of Sale) sales, POS) machines, personal digital assistants (PDAs), wearable devices, virtual reality devices, wireless U disks, Bluetooth audio/headphones, or mobile devices with antennas such as car front-mounted, driving recorders, security equipment, etc. or fixed terminal.

1 and 2 , in the embodiments of the present application, a mobile phone is used as an example of the above electronic device for description. The mobile phone provided in the embodiments of the present application may be a curved screen mobile phone or a flat screen mobile phone, and the present application implements the In the example, a flat screen mobile phone is used as an example for illustration. FIG. 1 and FIG. 2 respectively show the overall structure and the split structure of the mobile phone. The display screen 210 of the mobile phone provided by the embodiment of the present application may be a water drop screen, a notch screen, a full screen or a hole-digging screen (see FIG. 1 ) For example, the display screen 210 is provided with a first opening 211, and the following description takes a hole-digging screen as an example for description.

Referring to FIG. 2 , the mobile phone may include: a display screen 210 , a middle frame 220 , a rear case 250 , and a battery 240 located between the middle frame 220 and the rear case 250 , wherein the battery 240 may be disposed on the middle frame 220 toward the rear case 250 (as shown in FIG. 2 ), or the battery 240 may be arranged on the side of the middle frame 220 facing the display screen 210 , for example, the side of the middle frame 220 facing the rear case 250 may have a battery compartment (not shown in the figure), The battery 240 is installed in the battery compartment.

In some other examples, the mobile phone may further include a circuit board 230, wherein the circuit board 230 may be disposed on the middle frame 220, for example, the circuit board 230 may be disposed on the side of the middle frame 220 facing the rear case 250 (see FIG. 2 ). shown), or the circuit board 230 may be disposed on the side of the middle frame 220 facing the display screen 210 , and the display screen 210 and the rear case 250 are located on two sides of the middle frame 220 respectively.

The battery 240 can be connected to the charging management module and the circuit board 230 through the power management module, and the power management module receives the input of the battery 240 and/or the charging management module, and provides the processor, internal memory, external memory, display screen 210, camera, etc. The modules (for example, the front camera module 260 and the rear camera module 270 in FIG. 2 ) and the communication module are powered. The power management module can also be used to monitor parameters such as the capacity of the battery 240 , the number of cycles of the battery 240 , and the health status (electric leakage, impedance) of the battery 240 . In some other embodiments, the power management module may also be disposed in the processor of the circuit board 230 . In other embodiments, the power management module and the charging management module may also be provided in the same device.

When the mobile phone is a flat screen mobile phone, the display screen 210 can be an organic light-emitting diode (Organic Light-Emitting Diode, OLED) display screen, or can be a liquid crystal display (Liquid Crystal Display, LCD), when the mobile phone is a curved screen mobile phone, The display screen 210 may be an OLED display screen.

Continuing to refer to FIG. 2 , the middle frame 220 may include a metal middle plate 221 and a frame 222 , and the frame 222 is arranged around the outer periphery of the metal middle plate 221 for a circle. Generally, the frame 222 may include a top frame 2221, a bottom frame 2222, a left frame 2223 and a right frame 2224. The top frame 2221, the bottom frame 2222, the left frame 2223 and the right frame 2224 form a frame 222 with a square ring structure. . Wherein, the material of the metal middle plate 221 includes, but is not limited to, aluminum plate, aluminum alloy, stainless steel, steel-aluminum composite die-casting plate, titanium alloy or magnesium alloy, and the like. The frame 222 may be a metal frame, a ceramic frame, or a glass frame. When the frame 222 is a metal frame, the material of the metal frame includes, but is not limited to, aluminum alloy, stainless steel, steel-aluminum composite die-casting plate, or titanium alloy. Wherein, the metal middle plate 221 and the frame 222 may be clamped, welded, bonded or integrally formed, or the metal middle plate 221 and the frame 222 may be fixedly connected by injection molding.

Referring to FIG. 2 , the top frame 2221 and the bottom frame 2222 are oppositely arranged, the left frame 2223 and the right frame 2224 are oppositely arranged, and the top frame 2221 is connected with one end of the left frame 2223 and one end of the right frame 2224 in a rounded corner. , the bottom frame 2222 is connected with the other end of the left frame 2223 and the other end of the right frame 2224 respectively with rounded corners, thereby forming a rounded rectangular area together. The ground plane of the rear case is disposed in the rounded rectangular area, and is respectively connected with the top frame 2221 , the bottom frame 2222 , the left frame 2223 and the right frame 2224 . It can be understood that the ground plane of the rear case may be the rear case 250 of the mobile phone.

The rear shell 250 can be a metal rear shell, a glass rear shell, a plastic rear shell, or a ceramic rear shell. In the embodiment of the present application, the material of the rear shell 250 is not limited, and Not limited to the above examples.

It should be noted that, in some examples, the rear case 250 of the mobile phone may be connected with the frame 222 to form a unibody rear case. For example, the mobile phone may include: a display screen 210 , a metal middle plate 221 and a rear case, and the rear case may be The frame 222 and the rear case 250 are integrally formed into a rear case, so that the circuit board 230 and the battery 240 are located in the space enclosed by the metal middle plate 221 and the rear case.

In addition, in a possible implementation manner, the rear case 250 may also be provided with a second opening 251 to serve as a light-transmitting area of the rear camera module 270 . Similarly, the first opening 211 on the display screen 210 can also be used as a light-transmitting area of the front camera module 260 .

It should be noted that, in the embodiment of the present application, the above electronic device may also be a tablet computer as shown in FIG. 3 . Specifically, as shown in FIG. 3 , the tablet computer may at least include: a display screen 210 and a middle frame 220 , wherein the middle frame 220 may include: a metal middle plate 221 and a frame 222 , and the frame 222 is arranged around the outer circumference of the metal middle plate 221 .

It can be understood that the structures illustrated in the embodiments of the present application do not constitute a specific limitation on the electronic device 200 . In other embodiments of the embodiments of the present application, the electronic device 200 may include more or less components than shown, or combine some components, or separate some components, or arrange different components. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

In order to realize the communication function of the electronic device, an antenna may be provided on the electronic device to transmit and receive signals through the antenna. The antenna performance level of an electronic device in an actual usage scenario is directly related to the user's actual experience. At present, most electronic devices use the industrial design (Industry Design, ID) of metal frame and glass back shell. Due to the limited size of the metal frame and the tight antenna environment, antennas in certain frequency bands can only excite a single mode of the metal frame to minimize the size. Therefore, the performance of an antenna designed with a metal frame is greatly affected by the body part. Since body parts are dielectric, when body parts such as the head and hands are close to the antenna, the antenna will radiate to the body. When the transmit power of the antenna is high, the radiation to the human body may be large, and when the transmit power of the antenna is low, the signal may be poor.

The Specific Absorption Rate (SAR) can be used to indicate the magnitude of the antenna's radiation to the human body. Due to regulatory limitations of SAR values, the power of the antenna cannot be made very high. When the SAR value of the antenna is small, the transmit power of the antenna can be higher and the radiation to the human body is smaller, thereby improving the quality of the signal.

At present, the SAR value of the human body close to the electronic device at a distance of 5mm or 0mm is generally used to measure the radiation of the antenna to the human body. The SAR value in the 0mm state is higher than the SAR value in the 5mm state, and the radiation to the human body is greater. Generally, when the transmit power of the antenna is high, the radiation to the human body is large, and when the transmit power of the antenna is low, the radiation to the human body is small, but at the same time, the signal is poor. In the related art, in order to reduce the SAR value of the antenna, the radiation performance of the antenna in the free space will also be changed. Therefore, how to reduce the SAR value of the antenna at a distance of 0 mm from the human body without changing the radiation performance of the antenna in the free space is required in the field of antennas. A very important problem to be solved.

Based on this, embodiments of the present application provide a new low SAR antenna device and an electronic device having the low SAR antenna device. The low SAR antenna device can be applied to electronic devices (such as mobile phones or computers) to solve the above problems. technical problem. The low SAR antenna device is provided with at least one secondary radiation unit, one end of the secondary radiation unit is connected to the primary radiation unit, and the other end of the secondary radiation unit is connected to a feed source, which feeds the primary radiation unit and the secondary radiation unit respectively, and The resonant frequency of the secondary radiation unit does not resonate at the operating frequency of the main radiation unit, which can reduce the SAR value of the low SAR antenna device at a distance of 0 mm from the human body without changing the radiation performance of the low SAR antenna device in free space. , so that the radiation effect and radiation efficiency of the low SAR antenna device can be improved, thereby improving the user's use effect.

It should be noted that the low SAR antenna device provided in the present application is suitable for electronic equipment using any one or more of the following communication technologies, for example, long term evolution (LTE) communication technology, Wi-Fi communication technology, 5G Communication technology, SUB-6G communication technology and other communication technologies in the future.

The specific structure of the low SAR antenna device will be described in detail below with reference to the specific drawings (the following embodiments do not highlight the requirements of the communication network, and only describe the operating characteristics of the low SAR antenna device in terms of frequency).

Referring to FIG. 4 , an embodiment of the present application provides a low SAR antenna apparatus 100 , and the low SAR antenna apparatus 100 is applied to an electronic device 200 (see FIG. 3 ). Specifically, the low SAR antenna apparatus 100 may at least include : at least one main radiating unit 110, at least one feeding source 120 and at least one secondary radiating unit 130, wherein one end of the secondary radiating unit 130 is connected to the main radiating unit 110, and the other end of the secondary radiating unit 130 is connected to the feeding source 120, so as to The feeding source 120 is made to feed the main radiating unit 110 and the secondary radiating unit 130 respectively.

It can be understood that the embodiment of the present application does not limit the antenna form of the main radiation unit 110, for example, the main radiation unit 110 may be a monopole antenna, an inverted antenna, or a loop antenna.

Compared with the antenna device in the prior art as shown in FIG. 5 , the low SAR antenna device 100 provided by the embodiment of the present application adds a secondary radiation unit 130 (see FIG. 6 and FIG. 7 ). Specifically, in A secondary radiating element 130 is connected in series between the main radiating element 110 and the feed source 120 , and the secondary radiating element 130 does not resonate at the operating frequency of the main radiating element 110 .

Since the secondary radiating element 130 does not resonate at the operating frequency of the main radiating element 110, in this way, when the low SAR antenna device 100 is in a free space state and the main radiating element 110 operates in a resonant state, the resonant frequency of the secondary radiating element 130 is far away from The working frequency of the main radiating unit 110, that is, the secondary radiating unit 130 works in a non-resonant state. FIG. 8 is a schematic diagram of the antenna energy ratio of the low SAR antenna device 100 provided in an embodiment of the present application in a free space state. At this time, as shown in FIG. 8 , most of the energy of the low SAR antenna device 100 is radiated by the main radiation unit 110 , and the radiated energy of the secondary radiation unit 130 accounts for a small proportion, so the performance of the secondary radiation unit 130 to the main radiation unit 110 The impact is extremely small.

When the main radiation unit 110 is close to the human body 300 (as shown in FIG. 7 ), a part of the energy of the main radiation unit 110 will be reflected back by the human body 300 . FIG. 9 is a schematic diagram of the antenna energy ratio of the low SAR antenna device 100 provided by the embodiment of the present application when the human body is 0 mm in size. At this time, as shown in FIG. 9 , the radiation energy ratio of the main radiation unit 110 will be greatly reduced, and the radiation energy ratio of the secondary radiation unit 130 will be relatively greatly increased, so the 0mm SAR value of the main radiation unit 110 can be reduced. Therefore, the embodiments of the present application can reduce the SAR value of the low SAR antenna device 100 when the distance from the human body 300 is 0 mm, without changing the radiation performance of the low SAR antenna device 100 in free space, so that the low SAR antenna device can be improved 100 radiation effects.

It should be noted that, in this embodiment of the present application, the middle frame 220 of the electronic device 200 may be a metal middle frame, wherein the metal middle frame may at least include a metal frame, the metal frame may form a metal frame antenna, and the metal frame antenna serves as a low SAR antenna At least one main radiating element 110 in the antenna device 100 .

Specifically, the metal frame antenna may be the main radiating unit 110 located on the metal frame, and the main radiating unit 110 is formed by opening a slit on the metal frame. In other words, the metal frame antenna is a slot antenna formed by slits on the metal frame. . The slot antenna may include a first portion, a second portion, and a third portion separated by a slot, wherein the first portion and the second portion, the second portion and the third portion, and the third portion and the first portion Can be filled with non-conductive material. In this way, the main radiating unit 110 may be a metal radiator formed by cutting two slits in the metal frame of the electronic device 200 .

In practical applications, the positions of the gaps can be changed as required, and each gap can be filled with a non-conductive material (eg, plastic) to ensure the appearance integrity of the metal frame. By flexibly setting the opening positions of the slits on the metal frame, while ensuring the radiation performance of the antenna, the appearance design of different requirements can be realized, which is beneficial to improve the product quality of the electronic device 200 .

In addition, it can be understood that the feeding point and the grounding point of the power feeding source 120 may be respectively electrically connected to the metal middle plate 221 serving as the floor in the electronic device 200 .

In this embodiment of the present application, the resonant frequency of the secondary radiating unit 130 may be greater than the resonant frequency of the main radiating unit 110 . That is, the secondary radiating element 130 operates in a non-resonant state, and its resonant frequency is much higher than the operating frequency of the main radiating element 110 .

Specifically, the resonant frequency of the secondary radiating unit 130 may be 1 to 3 times the resonant frequency of the primary radiating unit 110 . If the resonant frequency of the secondary radiation unit 130 is too small, the free space state of the low SAR antenna device 100 will be affected. When the resonant frequency of the secondary radiation unit 130 is too large, the radiation capability of the secondary radiation unit 130 will be small, resulting in a low SAR antenna. The radiation effect of the device 100 is poor. When the resonant frequency of the secondary radiating element 130 is 1 to 3 times the resonant frequency of the main radiating element 110 , it will not affect the free space state of the low SAR antenna device 100 , but also ensure the radiation effect of the low SAR antenna device 100 . .

Referring to FIG. 4 , the low SAR antenna device 100 may further include: a first transmission line 140 and a second transmission line 150 , the number of secondary radiation units 130 is one, one end of the first transmission line 140 is connected to the main radiation unit 110 , and the first transmission line 140 is connected to the main radiation unit 110 . The other end of the transmission line 140 is connected to the secondary radiation unit 130 , one end of the second transmission line 150 is connected to the secondary radiation unit 130 , and the other end of the second transmission line 150 is connected to the feeder 120 . When the number of secondary radiation units 130 is one, it can ensure that one end of the secondary radiation unit 130 is connected to the main radiation unit 110, and the other end of the secondary radiation unit 130 is connected to the feeder 120, so as to ensure that the feeders 120 can be the main The radiation unit 110 and the secondary radiation unit 130 are fed in series.

In this embodiment of the present application, the length of the first transmission line 140 may be between 1/8 wavelength and 1 times the wavelength of the first transmission line 140 . The wavelength (λ) is the wavelength of the electromagnetic wave in the medium of the first transmission line 140 .

When the main radiation unit 110 is close to the human body 300, the radiation energy ratio of the main radiation unit 110 is greatly reduced, and the secondary radiation unit 130 is located near the maximum point of the standing wave current of the first transmission line 140 and the second transmission line 150, which can make the secondary radiation The radiation capability of the unit 130 is greatly enhanced. The length of the first transmission line 140 is between 1/8 wavelength and 1 times the wavelength of the first transmission line 140 , which ensures that the secondary radiation unit 130 is located near the maximum point of the standing wave current of the first transmission line 140 and the second transmission line 150 .

Specifically, in some embodiments, the length of the first transmission line 140 may be between 1/8 wavelength and 1/2 wavelength of the first transmission line 140 . The length of the first transmission line 140 is between 1/8 wavelength and 1/2 wavelength of the first transmission line 140. When the secondary radiation unit 130 is located between the first transmission line 140 and the second transmission line 150, the maximum standing wave current in the human body state When the range is near the point, the radiation capability of the secondary radiation unit 130 can be further improved.

Exemplarily, the length of the first transmission line 140 may be 1/8 wavelength, 1/7 wavelength, 1/6 wavelength, 1/5 wavelength, 1/4 wavelength, 1/3 wavelength or 1/2 wavelength of the first transmission line 140 The wavelength and the like are not limited in the embodiments of the present application, nor are they limited to the above examples.

Therefore, compared with the antenna device in the prior art as shown in FIG. 5 , that is, the main radiating element 110 and the feeding source 120 are directly connected through the transmission line 310 , in the embodiment of the present application, the main radiating element 110 and the feeding source are directly connected by the transmission line 310 . A secondary radiating element 130 is added to the feed transmission path between 120 and 120. At the same time, by utilizing the difference in the traveling wave and standing wave characteristics of the first transmission line 140 and the second transmission line 150, the secondary radiating element 130 only needs a small amount of free space radiation. With the energy ratio, the SAR value of the human body 300 can be greatly reduced when the distance from the low SAR antenna device 100 is 0 mm, and the impact on the performance of the main radiation unit 110 in the free space state is very weak.

Specifically, when the low SAR antenna device 100 is in a free space state, the signals of the first transmission line 140 and the second transmission line 150 are in a traveling wave state. At this time, when the main radiating element 110 operates in a resonance state, the resonant frequency of the auxiliary radiating element 130 is far away from the operating frequency of the main radiating element 110 , that is, the auxiliary radiating element 130 operates in a non-resonant state. Most of the energy of the low SAR antenna device 100 is radiated by the main radiation unit 110 , and the radiated energy of the secondary radiation unit 130 accounts for a small proportion. Therefore, the secondary radiation unit 130 has little influence on the performance of the primary radiation unit 110 .

When the main radiation unit 110 is close to the human body 300 , a part of the energy of the main radiation unit 110 will be reflected back by the human body 300 to form a standing wave on the first transmission line 140 and the second transmission line 150 . Since a part of the energy of the main radiation unit 110 is reflected and a part is absorbed by the human body 300 , the proportion of the radiation energy of the main radiation unit 110 is greatly reduced. The secondary radiation unit 130 is located near the maximum point of the standing wave current on the first transmission line 140 and the second transmission line 150 , so the radiation capability of the secondary radiation unit 130 is greatly enhanced. Because the radiation energy ratio of the main radiation unit 110 is weakened, and the energy ratio of the secondary radiation unit 130 is increased, the reduction of the 0 mm SAR value of the main radiation unit is achieved.

In addition, as shown in FIG. 6 or FIG. 7 , the low SAR antenna device 100 may further include: a matching circuit 160 , one end of the matching circuit 160 is connected to the main radiation unit 110 , and the other end of the matching circuit 160 is connected to the first transmission line 140 . By arranging the matching circuit 160 in the low SAR antenna device 100 , the achievable functions of the low SAR antenna device 100 can be increased, and further the achievable functions of the electronic device 200 having the low SAR antenna device 100 can be increased.

Wherein, in a possible implementation manner, the matching circuit 160 may at least include: any one or more of capacitance, inductance or resistance. Exemplarily, the matching circuit 160 may include only one or more capacitors, may only include one or more inductors, may include only one or more resistors, or may include both one or more capacitors and one or more inductors. , can also include one or more capacitors and one or more resistors, can also include one or more resistors and one or more inductors, can also include one or more capacitors, one or more inductors and a or multiple resistors, which is not limited in this embodiment of the present application.

In addition, it can be understood that the embodiment of the present application further provides another low SAR antenna device 100, as shown in FIG. 10 and FIG. 11 , the low SAR antenna device 100 shown in FIG. 10 and FIG. 11 is the same as the one shown in FIG. 4 . The difference from the low SAR antenna device 100 is that the number of the sub-radiation units 130 in the low SAR antenna device 100 may be two.

It should be noted that, in the embodiment of the present application, when the number of secondary radiation units 130 in the low SAR antenna device 100 is two, the specific structures and connection methods in the low SAR antenna device 100 include but are not limited to the following two possibilities implementation:

A possible implementation is: as shown in FIG. 10 , the low SAR antenna device 100 may include: a third transmission line 170 located between the first transmission line 140 and the second transmission line 150 , wherein one of the two secondary radiating units 130 One end of one is connected to the first transmission line 140 , the other end of one of the two sub-radiation units 130 is connected to the third transmission line 170 , and one end of the other of the two sub-radiation units 130 is connected to the third transmission line 170 The other end of the other of the two sub-radiation units 130 is connected to the second transmission line 150 .

In this way, it can be ensured that the two secondary radiating units 130 are connected in series with each other, one of the two secondary radiating units 130 is connected to the main radiating unit 110, and the other of the two secondary radiating units 130 is connected to the feeder 120, thereby ensuring that The feeding source 120 can feed the main radiating unit 110 and the two secondary radiating units 130 respectively at the same time.

Another possible implementation manner is: as shown in FIG. 11 , the low SAR antenna device 100 may include: a fourth transmission line 180 and a fifth transmission line 190 , one end of the fourth transmission line 180 is connected to the main radiating unit 110 , and the fourth transmission line The other end of 180 is connected to one end of one of the two sub-radiation units 130 , one end of the fifth transmission line 190 is connected to the other end of one of the two sub-radiation units 130 , and the other end of the fifth transmission line 190 Connected to the feed source 120 , one end of the other of the two sub-radiating elements 130 is connected to the first transmission line 140 , and the other end of the other of the two sub-radiating elements 130 is connected to the second transmission line 150 .

In this way, it can be ensured that the two secondary radiating units 130 are connected in parallel with each other, one of the two secondary radiating units 130 is connected to the main radiating unit 110 and the feeder 120 respectively, and the other of the two secondary radiating units 130 is connected to the main radiating unit 130 respectively. The radiation unit 110 and the feed source 120 are connected to ensure that the feed source 120 can feed the main radiation unit 110 and the two secondary radiation units 130 respectively at the same time.

It should be noted that, in this embodiment of the present application, for the same main radiating unit 110, any number of secondary radiating units 130 may be added on the feed path between the main radiating unit 110 and the feeding source 120. This embodiment of the present application The comparison is not limited. For example, three or more secondary radiating units 130 may be added on the feeding path between the main radiating unit 110 and the feeding source 120 .

In this embodiment of the present application, the secondary radiation unit 130 in the low SAR antenna device 100 may be a metal patch. Exemplarily, the secondary radiation unit 130 may be a metal patch made of copper, a metal patch made of silver, or a metal patch made of silver plated, which is not limited in this embodiment of the present application, nor is it limited to the above examples. In addition, the specific size of the secondary radiation unit 130 may be determined according to the resonant frequency of the main radiation unit 110 in an actual application scenario.

In the embodiment of the present application, the vertical distance between the sub-radiation unit 130 of the low SAR antenna device 100 and the metal middle plate may be 0.5 mm-3 mm. In this way, the radiation performance of the secondary radiation unit 130 can be ensured while ensuring that the secondary radiation unit 130 of the low SAR antenna device 100 is suspended in the air.

For example, the vertical distance between the secondary radiation unit 130 of the low SAR antenna device 100 and the metal middle plate may be 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, or 3 mm, etc., which is not specified in the embodiments of the present application. limitation, and not limited to the above examples. It should be noted here that the numerical values and numerical ranges involved in the embodiments of the present application are approximate values, and there may be errors in a certain range due to the influence of the manufacturing process, and those skilled in the art may consider these errors to be ignored.

FIG. 12 is a comparison diagram of the reflection coefficient ( S11 ) curve of the low SAR antenna device 100 provided by the embodiment of the present application compared with the antenna device in the prior art in a free space state. As can be seen from FIG. 12 , the low SAR antenna device 100 provided by the embodiment of the present application and the antenna device in the prior art both work at 2.4-2.5 GHz, which is the working frequency band of WIFI 2.4G, and the center frequency is 2.45 GHz. Therefore, it can be obtained that in the free space state, the secondary radiation unit 130 basically does not cause interference and influence on the operating frequency of the main radiation unit 110 .

FIG. 13 is a comparison diagram of radiation efficiency curves of the low SAR antenna device 100 provided by the embodiment of the present application compared with the antenna device in the prior art in a free space state. It can be seen from FIG. 13 that the radiation efficiency and system efficiency of the low SAR antenna device 100 provided by the embodiment of the present application, as well as the radiation efficiency and system efficiency of the antenna device in the prior art, are all about -1.3dB at 2.45 GHz , basically the same. Therefore, it can be obtained that in the free space state, the secondary radiation unit 130 basically does not cause interference or influence on the radiation efficiency and system efficiency of the main radiation unit 110 .

FIG. 14 is a radiation pattern at 2.45 GHz of the prior art antenna device in a free space state. FIG. 15 is a radiation pattern at 2.45 GHz of the low SAR antenna device 100 provided by the embodiment of the present application in a free space state. It can be seen with reference to FIGS. 14 and 15 that the low SAR antenna device 100 provided by the embodiment of the present application and the antenna device in the prior art have basically the same pattern and directivity coefficient. To sum up, the simulation results in FIGS. 12 to 15 show that the addition of the secondary radiating unit 130 basically has no effect on the radiation performance of the main radiating unit 110 in the free space state.

FIG. 16 is a comparison diagram of the reflection coefficient ( S11 ) curve of the low SAR antenna device 100 provided by the embodiment of the present application compared with the antenna device in the prior art when the human body is 0 mm. It can be seen from FIG. 16 that the low SAR antenna device 100 provided by the embodiment of the present application and the antenna device in the prior art have basically the same reflection coefficient at 2.45 GHz.

FIG. 17 is a comparison diagram of radiation efficiency curves of the low SAR antenna device 100 provided by the embodiment of the present application compared with the antenna device in the prior art when the human body is 0 mm. As can be seen from FIG. 17 , after the secondary radiation unit 130 is added to the low SAR antenna device 100 , the radiation efficiency and the system efficiency of the low SAR antenna device 100 are significantly improved when the distance between the human body 300 and the low SAR antenna device 100 is 0 mm, and approximately 6dB or so.

FIG. 18 is the SAR value of the antenna device in the prior art in the state of 0 mm of the human body. FIG. 19 is the SAR value of the low SAR antenna device 100 provided by the embodiment of the present application in a state of 0 mm of the human body. It can be seen from FIG. 18 and FIG. 19 that the SAR hot spot distributions of the low SAR antenna device 100 provided by the embodiment of the present application and the antenna device in the prior art are basically the same, but the low SAR antenna device provided by the embodiment of the present application has the same SAR hot spot distribution. The SAR value of 100 is 3.2 W/kg, and the SAR value of the antenna device in the prior art is 4.4 W/kg. Compared with the antenna device in the prior art, the SAR value of the low SAR antenna device 100 provided by the embodiment of the present application is 4.4 W/kg. The obvious decrease is due to the weakening of the radiation energy proportion of the main radiation unit 110 and the increase of the radiation energy proportion of the secondary radiation unit 130 .

To sum up, the above simulation results show that in this embodiment of the present application, a secondary radiating element 130 is added to the feed transmission path between the main radiating element 110 and the feeding source 120, and the traveling waves of the first transmission line 140 and the second transmission line 150 are utilized. Different from the standing wave characteristic, the secondary radiation unit 130 only needs a small proportion of free space radiated energy, which can greatly reduce the SAR value of the human body 0mm antenna, and has very little influence on the free space performance of the main radiation unit 110 .

In addition, it should be noted that in some embodiments, the secondary radiation unit 130 may be disposed on the inner surface of the battery cover, and specifically, the secondary radiation unit 130 may be a suspended metal, a graphene layer or a transparent conductive layer. Of course, in other embodiments, the secondary radiation unit 130 may not be limited to a suspended metal antenna, a graphene antenna, and a transparent antenna. For example, the secondary radiation unit 130 disposed on the inner surface of the battery cover 25 may also be other An antenna element provided on the inner surface of the battery cover 25 that can be coupled to radiate a signal.

In this way, most of the feeding network can be realized by the sub-radiating unit 130 disposed on the inner surface of the battery cover, so that the layout area of the antenna on the metal frame can be reduced, the influence on other antennas can be reduced, and the low SAR antenna device 100 can be implemented in a limited design space, which effectively saves the antenna design space inside the electronic device 200 to a certain extent. To a certain extent, the low SAR antenna device 100 can be implemented in a limited design space, effectively saving the antenna design space inside the electronic device 200 . Moreover, the low SAR antenna device 100 does not need additional slots on the metal frame of the middle frame 220 , which does not affect the industrial design appearance of the electronic device 200 , and at the same time, can effectively reduce the hand-holding effect.

It should be noted that the secondary radiation unit 130 may be printed or pasted on the inner surface of the rear case 250 , or the secondary radiation unit 130 may also be embedded in the inner surface of the rear case 250 . The specific arrangement on the inner surface of the case 250 is not limited, nor is it limited to the above examples. Certainly, in some other embodiments, the secondary radiation unit 130 may also be disposed on the outer surface of the rear shell 250 , which is not limited in this embodiment of the present application.

It can be understood that, in some embodiments, the low SAR antenna device 100 provided by the embodiments of the present application may include multiple groups of main radiation units 110 and multiple groups of sub-radiation units 130, so as to add more radiators. As the number increases, the low SAR antenna device 100 can achieve more patterns of coverage.

In addition, it should be noted that the main radiating unit 110 and the secondary radiating unit 130 may be a diversity antenna (DivAntenna), a WIFI antenna, a Bluetooth antenna, a GPS antenna, a main antenna (Main Antenna), or a mid-high frequency multiple-input-multiple-output (Multiple) -Input Multiple-Output, MIMO) antenna. Wherein, when the main radiation unit 110 is located at the bottom of the electronic device 200, the SAR value of the electronic device 200 can be lower.

In the description of the embodiments of the present application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a The indirect connection through an intermediate medium may be the internal communication of the two elements or the interaction relationship between the two elements. Those of ordinary skill in the art can understand the specific meanings of the above terms in the embodiments of the present application according to specific situations.

The devices or elements referred to in the embodiments of the present application or implied must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation on the embodiments of the present application. In the description of the embodiments of the present application, "plurality" means two or more, unless otherwise precisely and specifically specified.

The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the embodiments of the present application and the above-mentioned drawings are used to distinguish similar objects, while It is not necessary to describe a particular order or sequence. It is to be understood that data so used may be interchanged under appropriate circumstances such that embodiments of the embodiments of the application described herein can be implemented, for example, in sequences other than those illustrated or described herein. Furthermore, the terms "may include" and "have" and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those expressly listed but may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, but not to limit them. It should be understood that: it is still possible to modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements to some or all of the technical features, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the embodiments of the present application The scope of the technical solutions of each embodiment.

Claims (10)

1. A low SAR antenna device applied to electronic equipment is characterized by at least comprising:

at least one main radiating element and at least one feed;

further comprising: one end of the auxiliary radiating unit is connected with the main radiating unit, and the other end of the auxiliary radiating unit is connected with the power feed;

the feeding source feeds power to the main radiating element and the auxiliary radiating element respectively, and the auxiliary radiating element does not generate resonance on the working frequency of the main radiating element;

further comprising: a first transmission line and a second transmission line; one end of the first transmission line is connected with the main radiating unit, and the other end of the first transmission line is connected with the auxiliary radiating unit; one end of the second transmission line is connected with the auxiliary radiating unit, and the other end of the second transmission line is connected with the feed power supply;

the length of the first transmission line is between 1/8 lambda and lambda; wherein λ is the wavelength of the electromagnetic wave in the first transmission line medium.

2. The low SAR antenna device of claim 1, wherein the resonance frequency of the secondary radiating element is greater than the resonance frequency of the main radiating element, and the resonance frequency of the secondary radiating element is less than or equal to 3 times the resonance frequency of the main radiating element.

3. The low SAR antenna device of claim 1, wherein the length of the first transmission line is between 1/8 λ and 1/2 λ.

4. The low SAR antenna device according to any of claims 1 to 3, further comprising: a matching circuit; one end of the matching circuit is connected with the main radiating unit, and the other end of the matching circuit is connected with the first transmission line.

5. The low SAR antenna device of claim 4, characterized in that the matching circuit comprises at least: any one or more of a capacitor, an inductor, or a resistor.

6. The low SAR antenna device according to any of claims 1 to 3, further comprising: a third transmission line between the first transmission line and the second transmission line;

the number of the secondary radiation units is two; one end of one of the two auxiliary radiating elements is connected with the first transmission line, and the other end of one of the two auxiliary radiating elements is connected with the third transmission line; one end of the other of the two auxiliary radiating elements is connected with the third transmission line, and the other end of the other of the two auxiliary radiating elements is connected with the second transmission line.

7. The low SAR antenna device according to any of claims 1 to 3, further comprising: a fourth transmission line and a fifth transmission line;

the number of the secondary radiation units is two; one end of the fourth transmission line is connected with the main radiating element, and the other end of the fourth transmission line is connected with one end of one of the two auxiliary radiating elements; one end of the fifth transmission line is connected with the other end of one of the two auxiliary radiating units, and the other end of the fifth transmission line is connected with the power supply;

one end of the other of the two auxiliary radiating elements is connected with the first transmission line, and the other end of the other of the two auxiliary radiating elements is connected with the second transmission line.

8. An electronic device, characterized in that it comprises at least: display screen, backshell and be located the display screen with the center between the backshell still includes: the low SAR antenna device of any of the previous claims 1-7;

the middle frame is a metal middle frame, the metal middle frame at least comprises a metal frame, and the metal frame forms at least one main radiation unit in the low SAR antenna device.

9. The electronic device of claim 8, wherein the secondary radiating element in the low SAR antenna apparatus is a metal sheet.

10. The electronic device of claim 8, wherein the metal bezel further comprises: a metal middle plate; the metal frame is arranged around the periphery of the metal middle plate;

and the vertical distance between the auxiliary radiation unit of the low SAR antenna device and the metal middle plate is 0.5mm-3 mm.

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