Antenna and communication device

Abstract

The embodiment of the present application provides an antenna and a communication device, which relates to the technical field of communication devices, and can reduce the SAR value of the antenna on the top of the communication device to meet the antenna design requirements. The antenna includes: a main radiating unit, at least one end of the main radiating unit is located at the top of the communication device, and the main radiating unit is provided with a feeding point; a first parasitic unit, the first parasitic unit has a first coupling section, the first coupling section overlaps with a part of the main radiating unit, one end of the first parasitic unit extends toward the bottom of the communication device, and the first parasitic unit is provided with a first parasitic grounding point; a second parasitic unit, the second parasitic unit has a second coupling section, the second coupling section overlaps with a part of the main radiating unit, and the second parasitic unit is provided with a second parasitic grounding point. The antenna provided by the embodiment of the present application can be used for communication of communication equipment.

Description

[0001] This application is a divisional application. The application number of the original application is 2019114173649, and the original application date is December 31, 2019. The entire contents of the original application are incorporated into this application by reference. Technical Field

[0002] The present application relates to the technical field of communication equipment, and in particular to an antenna and a communication equipment. Background Art

[0003] At present, the communication function of communication equipment is realized by the antenna installed inside it. With the miniaturization of communication electronic equipment, the convenience and functionality of portable mobile communication equipment (such as mobile phones, etc.) have been greatly improved, and they have become an indispensable item in people's lives. When people use mobile phones, the antenna inside the mobile phone will bring radiation at one end. In order to limit the amount of radiation to ensure human health, the concept of SAR is often introduced. SAR (Specific Absorption Ratio) refers to the electromagnetic radiation energy absorbed by a unit mass of material per unit time. SAR values ​​are usually used internationally to measure the thermal effect of terminal radiation. Taking mobile phone radiation as an example, SAR represents the amount of radiation allowed to be absorbed per unit kilogram by an organism (including the human body). This SAR value represents the impact of radiation on the human body and is the most direct test value. SAR has data for the whole body, local area, and limbs. The lower the SAR value, the less radiation is absorbed. Therefore, after being manufactured, mobile devices such as mobile phones must meet certain SAR value indicators before they can be used. Generally, the FCC (Federal Communications Commission) standard requires that the SAR limit value be an average value of 1g for network access testing, and the limit value is no more than 1.6W / kg; the standards adopted by China and the European Union require that the SAR limit value be an average value of 10g for network access testing, and the limit value is no more than 2.0W / kg. For mobile phones, SAR has data for the whole body, local area, and limbs. Among them, the Head SAR (Head Specific Absorption Rate) for the head and the Body SAR (Body Specific Absorption Rate) for the body have a greater impact.

[0004] In recent years, the development trend of existing mobile phones is large screen-to-body ratio, narrow frame, and multiple cameras. In this way, the change of the mobile phone architecture has caused a significant reduction in the antenna clearance inside the mobile phone, especially the layout space at the bottom of the mobile phone is increasingly limited. With a small clearance, it is difficult to take into account both OTA (Over The Air, a technology for remote management of mobile terminal devices and SIM card data through the air interface of mobile communications) and SAR indicators at the same time by only using the lower antenna at the bottom of the mobile phone. In addition, considering the user experience of data services, using the top antenna to meet the standards has become a trend in mobile phone antenna design. Because the top antenna is closer to the human head in the usage scenario, how to make the top antenna meet the OTA and SAR indicators of more frequency bands at the same time has become the difficulty and key to the design of the top antenna of the mobile phone. Summary of the invention

[0005] The embodiments of the present application provide an antenna and a communication device, which can reduce the SAR value of the antenna on the top of the communication device and meet the antenna design requirements.

[0006] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0007] In a first aspect, an embodiment of the present application provides an antenna, including:

[0008] A main radiating unit, at least one end of which is located on the top of the communication device, and the main radiating unit is provided with a feeding point;

[0009] A first parasitic unit, the first parasitic unit having a first coupling section, the first coupling section being arranged to overlap with a portion of the main radiation unit, one end of the first parasitic unit extending toward the bottom of the communication device, and the first parasitic unit being provided with a first parasitic grounding point;

[0010] The second parasitic unit has a second coupling section, the second coupling section is overlapped with a part of the main radiation unit, and the second parasitic unit is provided with a second parasitic grounding point.

[0011] The antenna provided in the embodiment of the present application includes a main radiating unit, a first parasitic unit and a second parasitic unit. When the antenna is working, the first parasitic unit can be used as a working component to work in the required high-frequency band, and the main radiating unit can only be used as a power supply component of the first parasitic unit. Therefore, the radiation of the antenna is mainly at the first parasitic unit, and the radiation at the main radiating unit is very small. Furthermore, the radiation area of ​​the antenna is far away from the top of the communication device, which can reduce the radiation amount of people when using the communication device, especially the head, that is, reduce the Head SAR index. The setting of the second parasitic unit can have a shunting effect on the feeding of the antenna, disperse the working area of ​​the antenna, disperse the overall radiation of the antenna, and reduce the Body SAR value. Therefore, the SAR value of the antenna on the top of the communication device can be reduced while ensuring the function of the antenna, meeting the antenna design requirements.

[0012] In a first optional implementation of the first aspect, a first regulating switch is provided between the first coupling section of the first parasitic unit and the first parasitic grounding point, the first regulating switch is grounded, and is used to adjust the operating frequency of the first parasitic unit. The on and off of the first regulating switch can change the length of the current flowing through the first parasitic unit, thereby adjusting the operating frequency of the first parasitic unit, so that the first parasitic unit can operate in multiple different operating frequency bands.

[0013] In a second optional implementation of the first aspect, a second adjustment switch is provided between a feeding point of the main radiating unit and a region of the main radiating unit corresponding to the first coupling section, and the second adjustment switch is grounded and used to adjust the operating frequency of the main radiating unit. The frequency of the main radiating unit can be adjusted by turning the second adjustment switch on and off, so that the frequency band of the main radiating unit can be close to that of the first parasitic unit, and thus the first parasitic unit can be powered.

[0014] In a third optional implementation of the first aspect, both the first regulating switch and the second regulating switch are multi-throw switches, and the multi-throw switch has multiple branches with different impedance values. If the first regulating switch and the second regulating switch are only a switch circuit that can be turned on and off, then the transition of the operating frequency of the corresponding adjustable components may have only two states, that is, the switch is connected or disconnected. In order to enable the first regulating switch and the second regulating switch to switch the operating frequency of the corresponding layout in more different frequency bands, the first regulating switch and the second regulating switch are both multi-throw switches, and the multi-throw switch has multiple branches with different impedance values. In this way, the first regulating switch and the second regulating switch can not only adjust the operating frequency by turning on and off, but also, by switching in multiple different branches, the specific antenna operating frequency can have multiple different operating frequencies, thereby increasing the adjustable range. For example, among multiple branches, there can be a zero-ohm branch, and there can also be a branch with a larger resistance value (such as a capacitor, an inductor, etc.).

[0015] In a fourth optional implementation of the first aspect, the main radiating unit includes a horizontal segment, a bending segment, and a vertical segment that are connected in an integral manner. The horizontal segment is located at the top of the communication device, the vertical segment is located at the side of the communication device, and the bending segment is located at the corner of the communication device, connected to the horizontal segment and the vertical segment respectively, and the first coupling segment overlaps with the vertical segment. The position and structure of the main radiating unit can be flexibly set, and can be located entirely at the top of the communication device, or partially at the top of the communication device. In order to make the first parasitic unit farther away from the top of the communication device and further reduce the SAR value of the antenna on the top of the communication device, the main radiating unit includes a vertical segment, and then, the first coupling segment of the first parasitic unit overlaps with the vertical segment.

[0016] In a fifth optional implementation of the first aspect, the overlapping portion of the first coupling section of the first parasitic unit and the vertical section is parallel to each other. The overlapping portion of the first coupling section of the first parasitic unit and the vertical section needs to ensure the electric field excitation effect between them, so they cannot be connected. On this basis, in order to facilitate layout and production, the first parasitic unit and the vertical section can be made parallel to each other in the first coupling section.

[0017] In a sixth optional implementation of the first aspect, the distance between the first parasitic grounding point and the top of the communication device is greater than 55 mm. When the communication device is in use, the top of the communication device is generally closest to the human body (especially the head). Therefore, in principle, the farther the first parasitic unit is from the top of the communication device, the lower the corresponding Head SAR value will be. In view of this, after a large number of experimental verifications, when the distance between the first parasitic grounding point and the top of the communication device is greater than 55 mm, the Head SAR value of the antenna when working can meet the FCC standard.

[0018] In a seventh optional implementation of the first aspect, a length of the second coupling segment is greater than 3 mm.

[0019] In an eighth optional implementation of the first aspect, the distance between the second coupling section of the second parasitic unit and the main radiating unit is 1 to 3 mm. If the distance between the second coupling section of the second parasitic unit and the main radiating unit is too large, the current may not be transmitted normally, and if the distance is too small, no current excitation effect may be generated. Therefore, the distance may be 1 to 3 mm to ensure the second parasitic unit's loading of the main radiating unit and its shunting effect on the feeding.

[0020] In a ninth optional implementation of the first aspect, an extension section extends from a position of the main radiating unit near the feeding point toward the second parasitic unit, and the second parasitic unit includes a grounding section located in the second coupling section, and an extension section spaced apart from the extension section, and the extension section overlaps the extension section.

[0021] In a tenth optional implementation of the first aspect, the extension segment includes a first parallel segment connected to the ground segment, the first parallel segment is parallel to the extension segment, extends in a direction away from the main radiation unit, and is perpendicular to the ground segment.

[0022] In an eleventh optional implementation manner of the first aspect, the extension segment further includes a connecting segment connected to the first parallel segment, and the connecting segment is arranged at an end portion corresponding to the extension segment and is perpendicular to the first parallel segment.

[0023] In the twelfth optional implementation of the first aspect, the extension section also includes a second parallel section connected to the connecting section, the second parallel section is parallel to the extension section and extends in the direction of the main radiation unit, the second parallel section is perpendicular to the connecting section, and the first parallel section and the second parallel section are respectively located on both sides of the extension section.

[0024] In a thirteenth optional implementation manner of the first aspect, the second parallel section extends in the direction of the main radiation unit and exceeds the position of the extension section.

[0025] In a fourteenth optional implementation manner of the first aspect, the main radiating unit supplies power to the first parasitic unit through the first coupling section, and the main radiating unit supplies power to the second parasitic unit through the second coupling section.

[0026] In the fifteenth optional implementation of the first aspect, the communication device includes three parts from top to bottom, namely, a top part, a middle part and a bottom part. The top of the communication device includes the top edge of the communication device and a part within a first distance range from the top edge; the bottom of the communication device includes the bottom edge of the communication device and a part within a second distance range from the bottom edge.

[0027] In a sixteenth optional implementation of the first aspect, a receiver, a camera or an earphone jack is disposed on the top of the communication device, and a microphone, a speaker or a charging port is disposed on the bottom of the communication device.

[0028] In a second aspect, an embodiment of the present application provides an antenna, including:

[0029] A main radiating unit, at least one end of which is located on the top of the communication device, and the main radiating unit is provided with a feeding point;

[0030] The first parasitic unit has a first coupling section, the first coupling section is overlapped with the main radiation unit, one end of the first parasitic unit extends toward the bottom of the communication device, and the first parasitic unit is provided with a first parasitic grounding point.

[0031] The antenna provided in the embodiment of the present application includes a main radiation unit and a first parasitic unit, wherein at least one end of the main radiation unit is located at the top of the communication device, and the main radiation unit is provided with a feeding point; and the first parasitic unit has a first coupling section arranged to overlap with the main radiation unit, and the first coupling section is coupled with the main radiation unit, and then the main radiation unit can supply power to the first parasitic unit. One end of the first parasitic unit extends toward the bottom of the communication device, and a first parasitic grounding point is provided, so that when the antenna is working, the first parasitic unit can work as a working component in a required high-frequency band, and the main radiation unit can only serve as a power supply component of the first parasitic unit, thereby, at this time, the radiation of the antenna is mainly at the first parasitic unit, and the radiation at the main radiation unit is very little, and then, the radiation area of ​​the antenna is far away from the top of the communication device, which can reduce the radiation amount of people when using the communication device, especially the head, that is, reduce the Head SAR index, therefore, the SAR value of the antenna at the top of the communication device can be reduced while ensuring the function of the antenna, and the antenna design requirements are met.

[0032] In a first optional implementation of the second aspect, a first regulating switch is provided between the first coupling section and the first parasitic grounding point of the first parasitic unit, and the first regulating switch is grounded for adjusting the operating frequency of the first parasitic unit. In order to enable the first parasitic unit to operate in a plurality of different operating frequency bands, a first regulating switch is provided, and the first regulating switch is grounded, so that when the first regulating switch is disconnected, the current length of the first parasitic unit is from the first coupling section of the first parasitic unit to the first grounding point of the first parasitic unit and back to the ground; when the first regulating switch is connected, the current length of the first parasitic unit is from the first coupling section of the first parasitic unit to the first regulating switch and back to the ground. Therefore, the on and off of the first regulating switch can change the length of the current flowing through the first parasitic unit, and thus the operating frequency of the first parasitic unit can be adjusted.

[0033] As long as the first regulating switch is arranged between the first coupling section and the first parasitic grounding point of the first parasitic unit, the current length of the first parasitic unit can be changed, thereby adjusting the operating frequency of the first parasitic unit. Therefore, the position of the first regulating switch can be set according to actual needs. For example, in a second optional implementation of the second aspect, the first regulating switch is arranged corresponding to the first coupling section.

[0034] In a third optional implementation of the second aspect, a second adjustment switch is provided between the feeding point of the main radiating unit and the area of ​​the main radiating unit corresponding to the first coupling section, and the second adjustment switch is grounded for adjusting the operating frequency of the main radiating unit. The antenna needs to be able to work in multiple different frequency bands. The first parasitic unit is the main working component, and the adjustment of its operating frequency is achieved through the first adjustment switch. In this way, the first parasitic unit will need to be in multiple different frequency bands. At this time, in order to enable the main radiating unit to power the first parasitic unit, the main radiating unit needs to be close to the frequency band of the first parasitic unit to generate electric field excitation to power the first parasitic unit. Therefore, for the first parasitic unit that will be in multiple different frequency bands, a second adjustment switch is also provided on the main radiating unit, and the second adjustment switch is grounded. The frequency of the main radiating unit can be adjusted by turning the second adjustment switch on and off, so that the main radiating unit can be close to the frequency band of the first parasitic unit, and then the first parasitic unit can be powered. In addition, it should be noted that in order to make the first parasitic unit work, the main radiating unit only powers the first parasitic unit, and the frequency band of the main radiating unit is close to the operating frequency of the first parasitic unit and outside the operating frequency band of the first parasitic unit. Optionally, the frequency band of the main radiating unit is slightly larger than the frequency band of the first parasitic unit.

[0035] In a fourth optional implementation of the second aspect, both the first regulating switch and the second regulating switch are multi-throw switches, and the multi-throw switch has multiple branches with different impedance values. If the first regulating switch and the second regulating switch are only a switch circuit that can be turned on and off, then the transition of the operating frequency of the corresponding adjustable components may have only two states, that is, the switch is connected or disconnected. In order to enable the first regulating switch and the second regulating switch to switch the operating frequency of the corresponding layout in more different frequency bands, the first regulating switch and the second regulating switch are both multi-throw switches, and the multi-throw switch has multiple branches with different impedance values. In this way, the first regulating switch and the second regulating switch can not only adjust the operating frequency by turning on and off, but also, by switching in multiple different branches, the specific antenna operating frequency can have multiple different operating frequencies, thereby increasing the adjustable range. For example, among multiple branches, there can be a zero-ohm branch, and there can also be a branch with a larger resistance value (such as a capacitor, an inductor, etc.).

[0036] In a fifth optional implementation of the second aspect, the main radiating unit includes a horizontal section, a bending section and a vertical section that are connected in an integrated manner, the horizontal section is located at the top of the communication device, the vertical section is located at the side of the communication device, and the bending section is located at the corner of the communication device, and is used to connect the horizontal section and the vertical section, and the first coupling section is overlapped with the vertical section. The main radiating unit can be flexibly arranged, as long as one end is arranged at the top to facilitate the top antenna layout, and the other end is as close to the bottom of the communication device as possible, so that the first parasitic unit can be as far away from the top of the communication device as possible.

[0037] In a sixth optional implementation of the second aspect, the first parasitic unit and the vertical section are parallel to each other in the first coupling section. The part of the first parasitic unit located in the first coupling section and the part of the main radiation unit located in the first coupling section need to ensure the electric field excitation effect between them, so they cannot be connected. On this basis, in order to facilitate layout and production, the first parasitic unit and the vertical section can be made parallel to each other in the first coupling section.

[0038] When the communication device is in use, the top of the device is usually closest to the human body (especially the head). Therefore, in principle, the farther the first parasitic unit is from the top of the communication device, the lower the corresponding Head SAR value will be. In view of this, after a large number of experimental verifications, when the distance between the first parasitic grounding point and the top of the communication device is greater than 55 mm, the Head SAR value of the antenna when working can meet the FCC standard. Therefore, in combination with the first aspect and any one of the first to sixth optional implementations of the first aspect, in the seventh optional implementation of the first aspect, the distance between the first parasitic grounding point and the top of the communication device is greater than 55 mm. In addition, the distance between the first parasitic grounding point and the top of the communication device is used as a reference standard. This is proposed on the premise that when the communication device is in use, its top is the part closest to the human head. In actual production and design, specific consideration standards can be selected according to actual needs. For example, when the communication device is a mobile phone, the receiver of the mobile phone is closest to the human head when the mobile phone is making a call. Therefore, for mobile phones, the distance between the first parasitic grounding point and the receiver at the top of the mobile phone can be made greater than 55mm to ensure that the Head SAR value of the mobile phone antenna meets the FCC standard when it is working.

[0039] In a seventh optional implementation manner of the second aspect, the main radiation unit supplies power to the first parasitic unit through the first coupling section.

[0040] In an eighth optional implementation of the second aspect, the communication device includes three parts from top to bottom, namely, a top part, a middle part and a bottom part. The top of the communication device includes the top edge of the communication device and a part within a first distance range from the top edge; the bottom of the communication device includes the bottom edge of the communication device and a part within a second distance range from the bottom edge.

[0041] In a ninth optional implementation of the second aspect, a receiver, a camera or an earphone jack is disposed on the top of the communication device, and a microphone, a speaker or a charging port is disposed on the bottom of the communication device.

[0042] In a third aspect, an embodiment of the present application provides an antenna, characterized in that it includes:

[0043] A main radiating unit, at least one end of which is located on the top of the communication device, and the main radiating unit is provided with a feeding point;

[0044] The second parasitic unit has a second coupling section, the second coupling section is overlapped with the main radiation unit, and the second parasitic unit is provided with a second parasitic grounding point.

[0045] The antenna of the embodiment of the present application, the SAR value of the antenna also includes a Body SAR, and the value of the Body SAR also needs to comply with relevant regulations. The reduction of the Body SAR value is mainly achieved by dispersing the work of the antenna so that the radiation is not concentrated in a certain area. There are many solutions to reduce the Body SAR value in the related art. Here, on the basis of reducing the Head SAR value, it is considered to ensure that the Body SAR value does not exceed the standard. Therefore, after the second parasitic unit is set, the main radiating unit can supply power to the second parasitic unit through the second coupling section to make the second parasitic unit work. The second parasitic unit can have a shunting effect on the feeding of the antenna, so that the overall radiation of the antenna is dispersed and the Body SAR value is reduced.

[0046] In a first optional implementation manner of the third aspect, a length of the second coupling segment is greater than 3 mm.

[0047] In a second optional implementation of the third aspect, the distance between the second parasitic unit in the second coupling section and the main radiating unit is 1 to 3 mm. If the distance between the second parasitic unit in the second coupling section and the main radiating unit is too large, the current may not be transmitted normally, and if the distance is too small, no current excitation effect may be generated. Therefore, the distance may be 1 to 3 mm to ensure the second parasitic unit's loading of the main radiating unit and its shunting effect on the feeding.

[0048] In a third optional implementation of the third aspect, an extension section extends from a position of the main radiating unit near the feeding point toward the second parasitic unit, and the second parasitic unit includes a grounding section located in the second coupling section, and an extension section spaced apart from the extension section, and the extension section and the extension section are overlapped.

[0049] There are many ways to excite the second parasitic unit and the main radiating unit with current, such as the cross-type capacitor method. In the implementation of the cross-type capacitor, it is required that the second parasitic unit and the main radiating unit both have extended parts, which are spaced and staggered together. That is, the extended section of the second parasitic unit and the extended section of the main radiating unit are spaced and staggered together. Specifically, the extended section of the second parasitic unit includes a first parallel section, a connecting section, and a second parallel section.

[0050] In a fourth optional implementation of the third aspect, the extension segment includes a first parallel segment connected to the ground segment, the first parallel segment is parallel to the extension segment, extends in a direction away from the main radiation unit, and is perpendicular to the ground segment.

[0051] In a fifth optional implementation of the third aspect, the extension segment further includes a connecting segment connected to the first parallel segment, and the connecting segment is arranged at an end portion corresponding to the extension segment and is perpendicular to the first parallel segment.

[0052] In a sixth optional implementation of the third aspect, the extension section also includes a second parallel section connected to the connecting section, the second parallel section is parallel to the extension section and extends in the direction of the main radiation unit, the second parallel section is perpendicular to the connecting section, and the first parallel section and the second parallel section are respectively located on both sides of the extension section.

[0053] In a seventh optional implementation of the third aspect, the second parallel section extends in the direction of the main radiation unit and exceeds the position of the extension section.

[0054] The length of the second parallel section of the second parasitic unit can be set according to actual needs, and according to the set length, the final working state of the antenna may be different. For example, when the second parallel section extends toward the direction of the main radiating unit and exceeds the position of the extension section, at this time, the radiation of the extension section of the main radiating unit is blocked by the second parallel section, and the second parallel section is needed to work; if the second parallel section does not exceed the position of the extension section, at this time, the extension section of the main radiating unit can still work normally.

[0055] In addition, the above-mentioned antenna, including the main radiation unit, the first parasitic unit and the second parasitic unit, can be manufactured by FPC (Flexible Printed Circuit), LDS (Laser Direct Structuring), PDS (Printing Direct Structuring) or stainless steel molding process.

[0056] In an eighth optional implementation manner of the third aspect, the main radiation unit supplies power to the second parasitic unit through the second coupling section.

[0057] In a ninth optional implementation of the third aspect, the communication device includes three parts from top to bottom, namely, a top part, a middle part and a bottom part. The top of the communication device includes the top edge of the communication device and a part within a first distance range from the top edge; the bottom of the communication device includes the bottom edge of the communication device and a part within a second distance range from the bottom edge.

[0058] In a tenth optional implementation of the third aspect, a receiver, a camera or an earphone jack is disposed on the top of the communication device, and a microphone, a speaker or a charging port is disposed on the bottom of the communication device.

[0059] In a fourth aspect, an embodiment of the present application provides a communication device, including a housing, wherein the antenna of any one of the above-mentioned first aspects is provided at the top of the housing.

[0060] The communication device of the embodiment of the present application has the same technical effect as the antenna of any one of the first aspects described above, since it is provided near the top of the shell. That is, the antenna can reduce the SAR value of the antenna at the top of the communication device to meet the design requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 A schematic diagram of an antenna of a communication device according to a related art;

[0062] Figure 2 A schematic diagram of an antenna of a communication device according to a second related technology;

[0063] Figure 3 A structural schematic diagram of a first implementation method of an antenna of a communication device is provided for an embodiment of the present application;

[0064] Figure 4 A schematic diagram of a structure of a second implementation method of an antenna of a communication device is provided for an embodiment of the present application;

[0065] Figure 5 A schematic diagram of a third implementation of an antenna for a communication device is provided for an embodiment of the present application;

[0066] Figure 6 A schematic diagram of providing a first adjustment switch for a first parasitic unit of an antenna of a communication device according to an embodiment of the present application;

[0067] Figure 7 A schematic diagram of providing a second adjustment switch for a main radiation unit of an antenna of a communication device according to an embodiment of the present application;

[0068] Figure 8 A schematic diagram of providing a first parasitic unit and a second parasitic unit for an antenna of a communication device according to an embodiment of the present application;

[0069] Fig. 9 A schematic diagram of providing an extension section for a main radiation unit of an antenna of a communication device according to an embodiment of the present application;

[0070] Fig.10 A schematic diagram of the return loss of the antenna of the communication device provided in the embodiment of the present application;

[0071] Fig.11A return loss diagram of the antenna of the communication device provided in the embodiment of the present application with or without the second parasitic unit in the frequency band B3;

[0072] Fig.12 A return loss diagram of the antenna of the communication device provided in the embodiment of the present application with or without the second parasitic unit in the frequency band B1;

[0073] Fig.13 A hotspot distribution diagram of the presence or absence of a first parasitic unit when the antenna of the communication device provided in the embodiment of the present application is in the B2 frequency band;

[0074] Fig.14 A hotspot distribution diagram of the presence or absence of a first parasitic unit when the antenna of the communication device provided in the embodiment of the present application is in the B4 frequency band;

[0075] Fig.15 A hotspot distribution diagram of the presence or absence of a first parasitic unit when the antenna of the communication device provided in the embodiment of the present application is in the B7 frequency band;

[0076] Fig.16 A SAR value detection table for the presence or absence of a first parasitic unit when the antenna of the communication device provided in the embodiment of the present application is in the B2, B4 and B7 frequency bands;

[0077] Fig.17 The first parasitic unit resonance of the antenna of the communication device provided in the embodiment of the present application respectively covers the current distribution diagram of B7;

[0078] Fig.18 The first parasitic unit resonance of the antenna of the communication device provided in the embodiment of the present application respectively covers the current distribution diagram of B4;

[0079] Fig.19 A hotspot distribution diagram of the presence or absence of a second parasitic unit when the antenna of the communication device provided in the embodiment of the present application is in the B1 frequency band.

[0080] Reference numerals:

[0081] 1-antenna; 11-main antenna; 111-feeding unit; 12-first parasitic unit; 13-second parasitic unit; 14-first switch; 15-second switch; 2-circuit board; 3-antenna; 4-shielding layer; 31-radiation unit; 311-feeding end; 32-first coupling unit; 33-second coupling unit; 34-grounding unit; 100-housing; 200-antenna; 201-main radiation unit; 2011-feeding point; 2012-second adjustment switch; 20 13-horizontal section; 2014-bending section; 2015-vertical section; 2016-extension section; 202-first parasitic unit; 2021-first parasitic grounding point; 2022-first regulating switch; 203-first coupling section; 204-second parasitic unit; 2041-second parasitic grounding point; 2042-grounding section; 2043-extension section; 20431-first parallel section; 20432-connecting section; 20433-second parallel section; 205-second coupling section. DETAILED DESCRIPTION

[0082] The communication function of communication equipment is realized through the antenna installed inside it. When the antenna is working, it will generate certain radiation. It is not clear whether the radiation of the antenna will cause harm to the human body. However, various countries in the world have corresponding standards for antenna radiation. Only communication equipment with built-in antennas that meet this standard can be used. Taking mobile phones as an example, the antenna of mobile phones needs to be less than a certain SAR value while ensuring that it can normally cover the frequency band.

[0083] Reference Figure 1 , is a schematic diagram of an antenna of a communication device of the related art 1, the antenna 1 is arranged above the circuit board 2, the antenna 1 comprises a main antenna 11, the lower end of the main antenna 11 is connected to the circuit board 2, and is a feeding part 111, the first parasitic unit 12 and the second parasitic unit 13 are respectively arranged on both sides of the main antenna 11, the lower ends of the first parasitic unit 12 and the second parasitic unit 13 are respectively connected to the circuit board 2 and grounded through the first switch 14 and the second switch 15. The working state of the antenna 1 is changed by the on-off state of the first switch 14 and the second switch 15, and the antenna 1 will be in different working frequency bands and have different SAR values.

[0084] However, refer to Figure 1 , antenna 1 is set at a close distance, and different SAR values ​​are obtained by switching different states of antenna 1, and the SAR value can be reduced, mainly because the frequency and power of antenna 1 in different states are different, so it is possible to obtain a state with a smaller SAR value. And there is no corresponding solution for how to reduce the SAR value in a fixed frequency band.

[0085] Reference Figure 2, is a schematic diagram of an antenna of a communication device of related technology 2, wherein the antenna 3 is arranged on one side of a shielding layer 4 of the communication device, and comprises a radiation unit 31, a first coupling unit 32, and a second coupling unit 33, wherein one end of the radiation unit 31 is a feeding end 311, and one end of the first coupling unit 32 and the second coupling unit 33 are both connected to a grounding unit 34, and the radiation unit 31 and the first coupling unit 32 are arranged on the same horizontal plane, and a first gap is provided between them; the second coupling unit 33 is arranged below the radiation unit 31 and the first coupling unit 32, and a first distance is provided between the second coupling unit 33 and the radiation unit 31, and a second distance is provided between the second coupling unit 33 and the first coupling unit 32; by adjusting the first gap, the first distance, or the second distance, the SAR value of the antenna 3 can be reduced.

[0086] Reference Figure 2 In the related technology 2, the SAR value of the antenna 3 can be changed by adjusting the spacing between each antenna unit, and the longer the distance, the lower the SAR value. However, the first coupling unit 32 and the second coupling unit 33 are both connected to the grounding unit 34, and both need to be coupled with the radiation unit 31 to participate in the work of the antenna. If the first coupling unit 32 and the second coupling unit 33 are too far away from the radiation unit 31, although the SAR value can be reduced in theory, it may not be coupled normally due to the long distance, resulting in affecting the normal performance of the antenna. Therefore, the adjustment of the SAR value in the solution of the related technology 2 is limited, and it cannot guarantee compliance with the SAR value standards of countries around the world.

[0087] In addition, for mobile phones, the standards for SAR values ​​can be divided into Head SAR (head specific absorption rate) for the head and Body SAR (body specific absorption rate) for the body. Among them, the reduction of Body SAR is planar, and it only needs to disperse the working position of the antenna, that is, to shunt the current, which is relatively easy to achieve; however, the reduction of Head SAR is difficult to achieve in the current related technologies. Therefore, the embodiments of the present application focus on solving the problem of reducing the Head SAR value of the antenna.

[0088] The specific embodiments of this application refer to Figure 3 , a communication device provided in an embodiment of the present application, includes a housing 100 and an antenna 200 disposed near the top of the housing 100 .

[0089] The antenna 200 may be implemented in a variety of ways. For example, in a first embodiment of the antenna 200, the antenna 200 includes:

[0090] A main radiating unit 201, wherein at least one end of the main radiating unit 201 is located at the top of the communication device, and the main radiating unit 201 is provided with a feeding point 2011;

[0091] A first parasitic unit 202, wherein the first parasitic unit 202 has a first coupling section 203, the first coupling section 203 is overlapped with a portion of the main radiation unit 201, one end of the first parasitic unit 202 extends toward the bottom of the communication device, and the first parasitic unit 202 is provided with a first parasitic grounding point 2021;

[0092] The second parasitic unit 204 has a second coupling section 205 . The second coupling section 205 is overlapped with a part of the main radiation unit 201 . The second parasitic unit 204 is provided with a second parasitic grounding point 2041 .

[0093] The antenna 200 provided in the first embodiment of the present application is as follows Figure 3 , including a main radiation unit 201, a first parasitic unit 202 and a second parasitic unit 204. When the antenna is working, the first parasitic unit 202 can be used as a working component to work in the required high-frequency band, and the main radiation unit 201 can only be used as a power supply component for the first parasitic unit 202. Therefore, the radiation of the antenna is mainly at the first parasitic unit 202, and the radiation at the main radiation unit 201 is very small. Furthermore, the radiation area of ​​the antenna is far away from the top of the communication device, which can reduce the radiation amount of people when using the communication device, especially the head, that is, reduce the Head SAR index. The setting of the second parasitic unit 204 can have a shunting effect on the feeding of the antenna, disperse the working area of ​​the antenna, disperse the radiation of the antenna as a whole, and reduce the Body SAR value. Therefore, the SAR value of the antenna on the top of the communication device can be reduced while ensuring the function of the antenna, meeting the antenna design requirements.

[0094] In the second embodiment of the antenna 200, refer to Figure 4 , the antenna 200 comprises:

[0095] A main radiating unit 201, wherein at least one end of the main radiating unit 201 is located at the top of the communication device, and the main radiating unit 201 is provided with a feeding point 2011;

[0096] A first parasitic unit 202, wherein the first parasitic unit 202 has a first coupling section 203, the first coupling section 203 is overlapped with a portion of the main radiation unit 201, one end of the first parasitic unit 202 extends toward the bottom of the communication device, and the first parasitic unit 202 is provided with a first parasitic grounding point 2021;

[0097] The antenna 200 provided in the second embodiment of the present application is as follows: Figure 4, including a main radiation unit 201 and a first parasitic unit 202. When the antenna is working, the first parasitic unit 202 can be used as a working component to work in the required high-frequency band, and the main radiation unit 201 can only be used as a power supply component for the first parasitic unit 202. Therefore, the radiation of the antenna is mainly at the first parasitic unit 202, and the radiation at the main radiation unit 201 is very small. Furthermore, the radiation area of ​​the antenna is far away from the top of the communication device, which can reduce the radiation amount of people when using the communication device, especially the head, that is, reduce the Head SAR index. Therefore, the SAR value of the antenna on the top of the communication device can be reduced while ensuring the function of the antenna, meeting the antenna design requirements.

[0098] In the third embodiment of the antenna 200, refer to Figure 5 , the antenna 200 comprises:

[0099] The antenna 200 may be implemented in a variety of ways. For example, in a first embodiment of the antenna 200, the antenna 200 includes:

[0100] A main radiating unit 201, wherein at least one end of the main radiating unit 201 is located at the top of the communication device, and the main radiating unit 201 is provided with a feeding point 2011;

[0101] The second parasitic unit 204 has a second coupling section 205 . The second coupling section 205 is overlapped with a part of the main radiation unit 201 . The second parasitic unit 204 is provided with a second parasitic grounding point 2041 .

[0102] The antenna 200 provided in the first embodiment of the present application is as follows Figure 5 , including a main radiation unit 201 and a second parasitic unit 204. When the antenna is working, the main radiation unit 201 can supply power to the second parasitic unit 204 through the second coupling section 205, so that the second parasitic unit 204 works. The second parasitic unit 204 can have a shunting effect on the feeding of the antenna, disperse the working area of ​​the antenna, disperse the radiation of the antenna as a whole, and reduce the Body SAR value. Therefore, the SAR value of the antenna on the top of the communication device can be reduced while ensuring the function of the antenna, meeting the antenna design requirements.

[0103] It should be noted that the overlapping arrangement means that the projections of the two in one direction overlap. For example, the first coupling section 203 overlaps with a part of the main radiating unit 201, that is, the projections of the first coupling section 203 and a part of the main radiating unit 201 on the housing 100 of the communication device overlap. Similarly, the second coupling section 205 overlaps with a part of the main radiating unit 201, that is, the projections of the second coupling section 205 and a part of the main radiating unit 201 on the housing 100 of the communication device overlap.

[0104] In the antenna 200 provided in the embodiment of the present application, the main radiation unit 201 can supply power to the first parasitic unit 202 through the first coupling section 203. The main radiation unit 201 can supply power to the second parasitic unit 204 through the second coupling section 205.

[0105] In addition, refer to Figure 3 , Figure 4 and Figure 5 The communication device includes three parts from top to bottom, namely, the top, the middle and the bottom. The top of the communication device includes the top edge of the communication device and a part within a first distance range from the top edge; the bottom of the communication device includes the bottom edge of the communication device and a part within a second distance range from the bottom edge. The first distance and the second distance are determined according to the specific size and installed components during design and production, or divided according to the display area and the non-display area. For example, the non-display area above the display area is the top, the display area is the middle, and the non-display area below the display area is the bottom.

[0106] Generally, a receiver, a camera or an earphone jack is disposed on the top of the communication device, and a microphone, a speaker or a charging port is disposed on the bottom of the communication device.

[0107] In order to enable the first parasitic unit 202 to operate in a plurality of different operating frequency bands, such as Figure 6 As shown, a first regulating switch 2022 is provided between the first coupling section 203 of the first parasitic unit 202 and the first parasitic grounding point 2021. The first regulating switch 2022 is grounded and used to adjust the working frequency of the first parasitic unit 202. Since the first regulating switch 2022 is provided and the first regulating switch 2022 is grounded, when the first regulating switch 2022 is disconnected, the length of the current of the first parasitic unit 202 is from the first coupling section 203 of the first parasitic unit 202 to the first grounding point 2021 of the first parasitic unit 202 and back to the ground; when the first regulating switch 2022 is connected, the length of the current of the first parasitic unit 202 is from the first coupling section 203 of the first parasitic unit 202 to the first regulating switch 2022 and back to the ground. Therefore, the on and off of the first regulating switch 2022 can change the length of the current flowing through the first parasitic unit 202, and then the working frequency of the first parasitic unit 202 can be adjusted, so that the first parasitic unit 202 can work in multiple different working frequency bands.

[0108] Reference Figure 6 As long as the first regulating switch 2022 is disposed between the first coupling section 203 of the first parasitic unit 202 and the first parasitic grounding point 2021, the current length of the first parasitic unit 202 can be changed, thereby adjusting the operating frequency of the first parasitic unit 202. Therefore, the position of the first regulating switch 2022 can be set according to actual needs. Figure 6The first regulating switch 2022 shown in FIG. 1 is arranged corresponding to the first coupling section 203 .

[0109] The antenna 200 needs to be able to work in multiple different frequency bands. The first parasitic unit 202 is the main working component, and its working frequency is adjusted by the first adjustment switch 2022. In this way, the first parasitic unit 202 will be in multiple different frequency bands. At this time, in order to enable the main radiating unit 2021 to supply power to the first parasitic unit 202, the main radiating unit 201 also needs to be close to the frequency band of the first parasitic unit 2022 to generate electric field excitation to supply power to the first parasitic unit 202. That is, the main radiating unit 201 also needs to be adjustable in multiple different frequency bands. Therefore, referring to Figure 7 A second regulating switch 2012 is provided between the feeding point 2011 of the main radiating unit 201 and the area of ​​the main radiating unit 201 corresponding to the first coupling section 203. The second regulating switch 2012 is grounded and is used to adjust the working frequency of the main radiating unit 201. Similar to the principle of the first regulating switch 2022, the frequency of the main radiating unit 201 can be adjusted by turning on and off the second regulating switch 2012, so that the frequency band of the main radiating unit 201 can be close to that of the first parasitic unit 202, and then the first parasitic unit 202 can be powered.

[0110] In addition, it should be noted that in order to make the first parasitic unit 202 operate within the required frequency band, the main radiating unit 201 only supplies power to the first parasitic unit 202, and the main radiating unit 201 itself no longer needs the working frequency band. The frequency band of the main radiating unit 201 can be close to the working frequency of the first parasitic unit 202 and outside the working frequency band of the first parasitic unit 202. Optionally, the frequency of the main radiating unit 201 is slightly greater than the frequency of the first parasitic unit 202, and the frequency difference ranges from 100 to 200 MHz.

[0111] If the first regulating switch 2022 and the second regulating switch 2012 are only a switch circuit that can be turned on and off, then the change of the operating frequency of the corresponding adjustable component may have only two states, that is, the switch is connected or disconnected. In order to enable the first regulating switch 2022 and the second regulating switch 2012 to switch the operating frequency of the corresponding radiation unit in more different frequency bands, the first regulating switch 2022 and the second regulating switch 2012 are both multi-throw switches, and the multi-throw switch has multiple branches with different impedance values. In this way, the first regulating switch 2022 and the second regulating switch 2012 can not only adjust the operating frequency by turning on and off, but also, by switching in multiple different branches, the specific antenna operating frequency can have multiple different operating frequencies, thereby increasing the adjustable range. For example, among multiple branches, there can be a zero-ohm branch, and there can also be a branch with a larger resistance value (such as a capacitor and an inductor, etc.).

[0112] The main radiation unit 201 can be arranged flexibly, as long as one end of it is arranged at the top of the housing 100 to facilitate the top antenna layout, and the other end of it is as far as possible toward the bottom of the communication device, so that the first parasitic unit 202 can be as far away from the top of the communication device as possible. Figure 7 As shown, the main radiation unit 201 includes a horizontal section 2013, a bending section 2014 and a vertical section 2015 that are connected in one piece. The horizontal section 2013 is located at the top of the communication device, the vertical section 2015 is located at the side of the communication device, and the bending section 2014 is located at the corner of the communication device, which is used to connect the horizontal section 2013 and the vertical section 2015, and the first coupling section 203 is overlapped with the vertical section 2015. The position and structure of the main radiation unit 201 can be flexibly set, and can be located entirely at the top of the communication device, or partially at the top of the communication device. In order to make the first parasitic unit 202 farther from the top of the communication device and further reduce the SAR value of the antenna on the top of the communication device, the main radiation unit 201 includes a vertical section 2015, and then, the first coupling section 203 of the first parasitic unit 202 is overlapped with the vertical section 2015.

[0113] The overlapping portion of the first coupling section 203 of the first parasitic unit 202 and the vertical section 2015 of the main radiation unit 201 needs to ensure the electric field excitation effect between them, so they cannot be connected. On this basis, in order to facilitate layout and production, the overlapping portion of the first coupling section 203 of the first parasitic unit 202 and the vertical section 2015 can be made parallel to each other.

[0114] When the communication device is in use, its top is usually closest to the human body (especially the head). Therefore, in principle, the farther the first parasitic unit 202 is from the top of the communication device, the lower the corresponding Head SAR value will be. In view of this, after a large number of experimental verifications, when the distance between the first parasitic grounding point 2021 and the top of the communication device is greater than 55mm, the Head SAR value of the antenna when working can meet the FCC standard. Figure 7 , the distance L between the first parasitic grounding point 2021 and the top of the communication device is greater than 55mm. In addition, the distance between the first parasitic grounding point 2021 and the top of the communication device is used as a reference standard here, which is proposed under the premise that when the communication device is in use, its top is the part closest to the human head. In actual production and design, specific consideration standards can be selected according to actual needs. For example, when the communication device is a mobile phone, the receiver of the mobile phone is closest to the human head when the mobile phone is making a call. Therefore, for mobile phones, the distance between the first parasitic grounding point 2021 and the receiver at the top of the mobile phone can be greater than 55mm to ensure that the Head SAR value of the mobile phone antenna when working meets the FCC standard.

[0115] When the antenna 200 operates in a high frequency band, the SAR value is often relatively high. Since the first parasitic unit 202 is far away from the top of the communication device, when the antenna 200 operates in a high frequency band, the first parasitic unit 202 operates within the frequency band, while the main radiating unit 201 operates outside the frequency band and has a frequency close to that of the first parasitic unit 202. Therefore, the main radiating unit 201 with a feeding point 2011 does not operate and can supply power to the first parasitic unit 202, so that the radiation center of the antenna 200 is transferred to the first parasitic unit 202, which is far away from the communication device, to reduce the Head SAR value.

[0116] However, the SAR value of the antenna also includes a Body SAR value, and the value of the Body SAR value must also comply with relevant regulations. The Body SAR value can be reduced mainly by dispersing the work of the antenna 200 so that the radiation is not concentrated in a certain area. There are many solutions to reduce the Body SAR value in the relevant technology. Here, on the basis of reducing the Head SAR value, it is considered to ensure that the Body SAR value does not exceed the standard. Figure 8 As shown, a second parasitic unit 204 is also provided near the first end of the main radiating unit 201, and the second parasitic unit 204 has a second parasitic grounding point 2041. The main radiating unit 201 excites the second parasitic unit 204 to work by current. After the second parasitic unit 204 is provided at the first end of the main radiating unit 201, the main radiating unit 201 can supply power to the second parasitic unit 204 by current excitation, so that the second parasitic unit 204 works. The second parasitic unit 204 can have a shunting effect on the feeding of the antenna 200, so that the overall radiation of the antenna 200 is dispersed, thereby reducing the BodySAR value.

[0117] The specific configuration of the second parasitic unit 204 is as follows: Figure 8 As shown, the second parasitic grounding point 2041 is arranged at the first end of the second parasitic unit 204, the feeding point 2011 is arranged at the first end of the main radiating unit 201, and the second parasitic unit 204 has a second coupling section 205, and the second coupling section 205 and a part of the main radiating unit 201 are arranged to overlap. The second parasitic unit 204 and the main radiating unit 201 can be current-excited through the second coupling section 205 to ensure that the second parasitic unit 204 can work normally.

[0118] like Figure 8 As shown, the length of the second coupling section 205 is the length of the coupling area between the second parasitic unit 204 and the main radiation unit 201. It has been verified in practice that when the length M is not less than 3 mm, the normal current excitation effect between the main radiation unit 201 and the second parasitic unit 204 can be guaranteed.

[0119] If the distance between the second coupling section 205 of the second parasitic unit 204 and the main radiation unit 201 is too large, the current may not be transmitted normally. If the distance is too small, the current excitation effect may not be generated. Therefore, the distance also needs to have a range value. It has been verified in practice that Figure 8 As shown, when the distance D between the second coupling section 205 of the second parasitic unit 204 and the main radiating unit 201 is 1-3 mm, the normal current excitation effect between the main radiating unit 201 and the second parasitic unit 204 can be guaranteed, that is, the second parasitic unit 204 can load the main radiating unit 201 and shunt the feeding to reduce the BodySAR value.

[0120] The current excitation implementation method between the second parasitic unit 204 and the main radiation unit 201 can be flexibly set according to the actual needs. Fig. 9 The main radiating unit 201 has an extension section 2016 extending from a position close to the feeding point 2011 toward the second parasitic unit 204. The second parasitic unit 204 includes a grounding section 2042 located in the second coupling section 205, and an extension section 2043 spaced apart from the extension section 2016. The extension section 2043 overlaps with the extension section 2016.

[0121] There are many ways to excite the second parasitic unit 204 and the main radiating unit 201 with current, such as the method of interdigital capacitors. In the implementation of the interdigital capacitors, it is required that both the second parasitic unit 204 and the main radiating unit 201 have extended parts, which are spaced and interlaced. That is, the extension section 2043 of the second parasitic unit 204 is spaced and interlaced with the extension section 2016 of the main radiating unit 201. Specifically, the extension section 2043 of the second parasitic unit 204 includes a first parallel section 20431, a connecting section 20432 and a second parallel section 20433.

[0122] like Figure 3 As shown, the extension section 2043 includes a first parallel section 20431 connected to the ground section 2042. The first parallel section 20431 is parallel to the extension section 2016, extends in a direction away from the main radiation unit 201, and is perpendicular to the ground section 2042.

[0123] The extension section 2043 further includes a connecting section 20432 connected to the first parallel section 20431. The connecting section 20432 is disposed at an end portion of the extension section 2016 and is perpendicular to the first parallel section 20431.

[0124] The extension section 2043 also includes a second parallel section 20433 connected to the connecting section 20432. The second parallel section 20433 is parallel to the extension section 2016 and extends toward the direction of the main radiation unit 201. The second parallel section 20433 is perpendicular to the connecting section 20432. The first parallel section 20431 and the second parallel section 20433 are respectively located on both sides of the extension section 2016.

[0125] The length of the second parallel section 20433 of the second parasitic unit 204 can be set according to actual needs, and according to the set length, the final working state of the antenna 200 may be different. For example, when the second parallel section 20433 extends toward the direction of the main radiation unit 201 and exceeds the position of the extension section 2016, at this time, the radiation of the extension section 2016 of the main radiation unit 201 is blocked by the second parallel section 20433, and the second parallel section 20433 is needed to work; if the second parallel section 20433 does not exceed the position of the extension section 2016, at this time, the extension section 2016 of the main radiation unit 201 can still work normally. Therefore, optionally, the second parallel section 20433 extends toward the direction of the main radiation unit 201 and exceeds the position of the extension section 2016.

[0126] In addition, the above-mentioned antenna, including the main radiation unit, the first parasitic unit and the second parasitic unit, can be manufactured by FPC (Flexible Printed Circuit), LDS (Laser Direct Structuring), PDS (Printing Direct Structuring) or stainless steel molding process.

[0127] In order to verify the actual SAR reduction effect of the antenna 200 of the embodiment of the present application, the antenna 200 was tuned to different frequency bands, and the antenna 200 was simulated and tested to obtain a return loss diagram; and the hot spots of the antenna 200 when working were measured to obtain a hot spot map and a current distribution map.

[0128] It should be noted that mobile phone antennas can operate in different frequency bands, and the signal frequency bands corresponding to different countries and operators are different. For these multiple different frequency bands, B1, B2, B3, B4, B5, B6, B7, B8, etc. are generally used for the convenience of representation, and each corresponds to a frequency band. Among them, B5, B6 and B8 are low-frequency bands. When the antenna works in this frequency band, the SAR value is small. Therefore, the embodiment of the present application does not perform low-frequency detection during actual verification.

[0129] Reference Fig.10When the distance D between the second parasitic unit 204 and the feeding point 2011 is between 1mm and 3mm, the second parasitic unit 204 is used to load the main radiating unit 201 and shunt the feeding to improve the high-frequency impedance and reduce the BodySAR. In addition, the coupling length L of the parallel coupling area (second coupling section 205) between the main radiating unit 201 and the second parasitic unit 204 is not less than 3mm. Considering the high Head SAR characteristics of the second parasitic unit 204 at the top of the housing 100 of the communication device, the resonance of the second parasitic unit 204 is adjusted to around 1.5GHz (resonance ④), and only its loading and shunt effects are used. At the same time, the main radiating unit 201 is adjusted to the out-of-band of the required high-frequency resonance (resonance ⑤⑥). By adjusting the second parasitic unit 204 and the main radiating unit 201 to the out-of-band mode, the corresponding resonance in the high-frequency band can be excited by adding the capacitively coupled first parasitic unit 202. At this time, the first parasitic unit 202 can be used to work in the high-frequency band, while the second parasitic unit 204 and the main radiating unit 201 do not participate in the high-frequency work, and the radiation of the antenna is mainly at the first parasitic unit 202 far from the top of the shell 100. Therefore, the Head SAR value can be reduced. Furthermore, after the first adjustment switch 2022 is set, the first parasitic unit 202 can cover the high frequencies B7, B2, and B4 (resonances ①②③) by switching the first adjustment switch 2022; in this process, when the resonance of the first parasitic unit 202 is switched, the out-of-band resonance of the main radiating unit 201 is adjusted by the second adjustment switch 2012 to make it close to the resonance of the first parasitic unit 202, thereby improving the parasitic effect of the first parasitic unit 202. In addition, the second parasitic unit 204 has the effect of improving the high-frequency impedance as shown in FIG. Fig.11 and Fig.12 As shown, in the frequency bands B1 and B3, the signal strength is significantly better with the second parasitic unit 204 than without the second parasitic unit 204 .

[0130] like Fig.13 , Fig.14 and Fig.15 As shown, the hot spot distribution diagrams of the antenna 200 in the LTE B2, B4 and B7 frequency bands are respectively shown without the first parasitic unit 202 and with the first parasitic unit 202. It can be obviously seen that in the high frequency bands of LTE B2, B4 and B7, the hot spot of the antenna 200 moves downward as a whole, the high frequency Head SAR hot spot is dispersed, and a certain hot spot distribution is formed in the area near the bottom of the Head, which is biased towards the position of the first parasitic unit 202, that is, the distance from the top of the housing 100 of the communication device becomes farther, thereby reducing the Head SAR value.

[0131] In addition, if Fig.16As shown, after actual measurement, the Head SAR values ​​of the antenna in the LTE B2, B4 and B7 frequency bands are obtained without the first parasitic unit 202 and with the first parasitic unit 202. It can be seen that when there is no first parasitic unit 202, the 1G Head SAR of the B7, B2 and B4 frequency bands are all high, with the maximum exceeding 2.0. If the first parasitic unit 202 is switched to cover the high-frequency resonance, the SAR value is significantly reduced, all below 1, and the SAR reduction amplitude exceeds 50%, and the effect is obvious.

[0132] Refer to Fig.17 and 18 , which is the current distribution of B7 and B4 covered by the resonance of the first parasitic unit 202. It can be seen that a strong current distribution is formed on the first parasitic unit 202 far away from the top area of ​​the communication device, thereby playing a role in reducing the Head SAR, which also verifies the effect of reducing the Head SAR.

[0133] Regarding the Body SAR reduction effect of the second parasitic unit 204, Fig.19 As shown, it is a hot spot distribution diagram of the antenna 200 without the second parasitic unit 204 and with the second parasitic unit 204 when in the WCDMA B1 frequency band. It can be clearly seen that the hot spots of the antenna 200 are expanded and dispersed when the second parasitic unit 204 is added compared to the solution without the second parasitic unit 204, which further proves that the shunting effect of adding the second parasitic unit 204 can reduce the Body SAR value.

[0134] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An antenna, characterized in that: include: A main radiating unit, wherein at least one end of the main radiating unit is located at the top of the communication device, and the main radiating unit is provided with a feeding point; A first parasitic unit, wherein the first parasitic unit has a first coupling section, the first coupling section is overlapped with a portion of the main radiation unit, one end of the first parasitic unit extends toward the bottom of the communication device, and the first parasitic unit is provided with a first parasitic grounding point; The first parasitic grounding point is arranged at an end of the first parasitic unit close to the bottom of the communication device; a second parasitic unit, wherein the second parasitic unit has a second coupling section, the second coupling section is overlapped with a part of the main radiation unit, and the second parasitic unit is provided with a second parasitic grounding point; The main radiating unit has an extension section extending from a position close to the feeding point toward the second parasitic unit, and the second parasitic unit includes a grounding section located in the second coupling section, and an extension section spaced apart from the extension section, and the extension section overlaps with the extension section.

2. The antenna according to claim 1, characterized in that A first regulating switch is provided between the first coupling section of the first parasitic unit and the first parasitic grounding point. The first regulating switch is grounded and is used to adjust the operating frequency of the first parasitic unit.

3. The antenna according to claim 2, characterized in that: A second regulating switch is provided between the feeding point of the main radiating unit and a region of the main radiating unit corresponding to the first coupling section. The second regulating switch is grounded and is used for adjusting the operating frequency of the main radiating unit.

4. The antenna according to claim 3, characterized in that The first regulating switch and the second regulating switch are both multi-throw switches, and the multi-throw switches have multiple branches with different impedance values.

5. The antenna according to any one of claims 1 to 4, characterized in that: The main radiation unit includes a horizontal section, a bending section and a vertical section that are integrally connected. The horizontal section is located at the top of the communication device, the vertical section is located at the side of the communication device, and the bending section is located at the corner of the communication device, respectively connected to the horizontal section and the vertical section, and the first coupling section is overlapped with the vertical section.

6. The antenna according to claim 5, characterized in that The overlapped portion of the first coupling segment and the vertical segment of the first parasitic unit is parallel to each other.

7. The antenna according to any one of claims 1 to 4, characterized in that: The distance between the first parasitic grounding point and the top of the communication device is greater than 55 mm.

8. The antenna according to any one of claims 1 to 4, characterized in that: The length of the second coupling section is greater than 3 mm.

9. The antenna according to any one of claims 1 to 4, characterized in that: The distance between the second coupling section of the second parasitic unit and the main radiation unit is 1-3 mm.

10. The antenna according to claim 1, characterized in that: The extended section includes a first parallel section connected to the ground section. The first parallel section is parallel to the extended section, extends in a direction away from the main radiation unit, and is perpendicular to the ground section.

11. The antenna according to claim 10, characterized in that: The extension section further includes a connecting section connected to the first parallel section. The connecting section is arranged corresponding to the end of the extension section and is perpendicular to the first parallel section.

12. The antenna according to claim 11, characterized in that The extended section also includes a second parallel section connected to the connecting section, the second parallel section is parallel to the extended section and extends toward the main radiation unit, the second parallel section is perpendicular to the connecting section, and the first parallel section and the second parallel section are respectively located on both sides of the extended section.

13. The antenna according to claim 12, characterized in that: The second parallel section extends toward the main radiation unit and exceeds the position of the extending section.

14. The antenna according to any one of claims 1 to 4, characterized in that: The main radiating unit supplies power to the first parasitic unit through the first coupling section, and the main radiating unit supplies power to the second parasitic unit through the second coupling section.

15. The antenna according to any one of claims 1 to 4, characterized in that: The communication device includes three parts from top to bottom, namely, a top part, a middle part and a bottom part. The top of the communication device includes the top edge of the communication device and a part within a first distance range from the top edge; the bottom of the communication device includes the bottom edge of the communication device and a part within a second distance range from the bottom edge.

16. The antenna according to claim 15, characterized in that The top of the communication device is provided with an earpiece, a camera or an earphone hole, and the bottom of the communication device is provided with a microphone, a speaker or a charging port.

17. A communication device, comprising a housing, characterized in that: The antenna according to any one of claims 1 to 16 is disposed at the top of the housing.

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