Circuit structure, packaging chip and electronic equipment

Abstract

The invention discloses a circuit structure, a packaging chip and electronic equipment, and relates to the technical field of circuits. The circuit structure comprises a signal isolation module, an impedance matching module, an NFC module, a radio frequency module, an SAR sensor and an antenna. Wherein the NFC module, the radio frequency module and the SAR sensor are connected with the antenna through the signal isolation module. Under the condition that the NFC module, the radio frequency module and the SAR sensor do not interfere with one another, the NFC module can perform near field communication through the antenna; the radio frequency module can perform cellular communication through the antenna; the SAR sensor can determine the distance between the human body and the antenna in the circuit structure through the antenna. Therefore, the NFC module, the radio frequency module and the SAR sensor can share one antenna, so that the requirements of application scenes of the electronic equipment can be met.

Description

Technical Field

[0001] The present application relates to the field of circuit technology, and in particular to a circuit structure, a packaged chip, and an electronic device. Background Art

[0002] With the rapid development of electronic devices, more and more functions are integrated into electronic devices such as mobile phones, tablet computers, and smart watches. For example, current electronic devices have integrated near field communication (NFC) functions. To implement NFC functions, the electronic device needs to be equipped with an NFC antenna and an NFC module connected to the NFC antenna.

[0003] In related technologies, electronic devices are also provided with a specific absorption rate (SAR) antenna and a SAR sensor connected to the SAR antenna. The SAR sensor can determine the distance between the human body and the SAR antenna through the SAR antenna. When the electronic device is working, the electromagnetic radiation power of the electronic device can be reduced when the distance between the human body and the SAR antenna is less than or equal to a preset distance to reduce the impact of electromagnetic radiation on the human body. Based on the requirements of the application scenario of the electronic device, the NFC antenna and the SAR antenna may need to be in the same position. In other words, the NFC antenna and the SAR antenna need to be the same antenna.

[0004] Therefore, how to make the NFC module and the SAR sensor share a common antenna has become an urgent problem to be solved. Summary of the Invention

[0005] The present invention provides a circuit structure, a packaged chip, and an electronic device. When the circuit structure is applied to an electronic device, an NFC module, a SAR sensor, and a radio frequency module can share a single antenna, thereby meeting the requirements of the electronic device's application scenarios. The technical solution is as follows:

[0006] In a first aspect, a circuit structure is provided. The circuit structure is applied to an electronic device. The circuit structure includes a signal isolation module, an impedance matching module, an NFC module, a radio frequency module, a SAR sensor, and an antenna.

[0007] The signal isolation module has a first end, a second end, a third end and a fourth end. The first end of the signal isolation module is connected to the first end of the impedance matching module, and the second end of the impedance matching module is connected to the NFC module. The second end of the signal isolation module is connected to the radio frequency module. The third end of the signal isolation module is connected to the SAR sensor. The fourth end of the signal isolation module is connected to the feeding point of the antenna. In this way, the NFC module can perform near-field communication through the antenna. In the process of the NFC module performing near-field communication through the antenna, the impedance matching module is used to adapt the internal impedance of the NFC module to the external impedance (i.e., the load impedance). The radio frequency module can perform cellular communication through the antenna. The SAR sensor can determine the distance between the human body and the antenna in the circuit structure through the antenna. The signal isolation module is used to prevent the NFC module, the radio frequency module, and the SAR sensor from interfering with each other.

[0008] In an embodiment of the present application, the circuit structure includes a signal isolation module, an impedance matching module, an NFC module, a radio frequency module, a SAR sensor, and an antenna. The NFC module, radio frequency module, and SAR sensor are all connected to the antenna via the signal isolation module. Thus, without interfering with each other, the NFC module can perform near-field communication via the antenna; the radio frequency module can perform cellular communication via the antenna; and the SAR sensor can determine the distance between the human body and the antenna in the circuit structure via the antenna. In other words, the NFC module, radio frequency module, and SAR sensor can share a single antenna, which can meet the requirements of the application scenarios of electronic devices.

[0009] The circuit structure provided in the embodiment of the present application is explained in detail below from two possible solutions.

[0010] The first possible solution.

[0011] In some embodiments, the signal isolation module includes a first inductor, a first capacitor, and a second inductor. The first end of the first inductor is connected to the first end of the impedance matching module. The first plate of the first capacitor is connected to the RF module. The first end of the second inductor is connected to the SAR sensor. The second end of the first inductor, the second plate of the first capacitor, and the second end of the second inductor are all connected to a feed point.

[0012] The impedance matching module includes a third capacitor, a fourth capacitor, a fifth capacitor, and a third inductor. The first plate of the third capacitor is connected to the first end of the signal isolation module, and the second plate of the third capacitor is connected to the ground wire. The first plate of the fourth capacitor is connected to the first end of the signal isolation module, and the second plate of the fourth capacitor is connected to the first plate of the fifth capacitor and the first end of the third inductor. The second plate of the fifth capacitor is connected to the ground wire. The second end of the third inductor is connected to the NFC module.

[0013] In some specific embodiments, the circuit structure should meet the following conditions: the capacitance value of the feed point is less than or equal to a preset capacitance value. The preset capacitance value is the background capacitance threshold of the SAR sensor. The antenna, first inductor, and impedance matching module should meet the following conditions: the external impedance of the NFC module is within a preset impedance range. The preset impedance range is the preset external impedance range of the NFC module. The preset external impedance range of the NFC module depends on the internal impedance of the NFC module. In this possible solution, the inductance value of the first inductor can be increased while the capacitance value of the impedance matching module can be reduced. This can maintain the external impedance of the NFC module unchanged while reducing the capacitance value of the feed point.

[0014] The second possible solution.

[0015] In some embodiments, the signal isolation module includes a first inductor, a first capacitor, a second inductor, and a second capacitor. The first end of the first inductor is connected to the first end of the impedance matching module. The first plate of the first capacitor is connected to the RF module. The first end of the second inductor is connected to the SAR sensor. The second end of the second inductor is connected to the first plate of the second capacitor. The second end of the first inductor, the second plate of the first capacitor, and the second plate of the second capacitor are all connected to the feed point.

[0016] The impedance matching module includes a third capacitor, a fourth capacitor, a fifth capacitor, and a third inductor. The first plate of the third capacitor is connected to the first end of the signal isolation module, and the second plate of the third capacitor is connected to the ground wire. The first plate of the fourth capacitor is connected to the first end of the signal isolation module, and the second plate of the fourth capacitor is connected to the first plate of the fifth capacitor and the first end of the third inductor. The second plate of the fifth capacitor is connected to the ground wire. The second end of the third inductor is connected to the NFC module.

[0017] In some specific embodiments, the circuit structure should meet the following conditions: the capacitance at the connection between the SAR sensor and the first end of the second inductor is less than or equal to a preset capacitance value. The preset capacitance value is the background capacitance threshold of the SAR sensor. In some possible embodiments, the capacitance of the second capacitor is greater than or equal to 100 pico-farads and less than or equal to 10 nF.

[0018] In some embodiments, the SAR sensor is provided with a first preset capacitance value range. The first preset capacitance value range is used to determine that the distance between the human body and the antenna in the circuit structure is less than or equal to the preset distance. The minimum value of the first preset capacitance value range is The maximum value of the first preset capacitance value range is Among them, C Q is the capacitance between the feeding point and the ground line, and C2 is the capacitance of the second capacitor. minis the minimum value of the second preset capacitance value range, ΔC max The second preset capacitance value range is used to determine whether the distance between the human body and the antenna is less than or equal to the preset distance when the SAR sensor is only connected to the antenna.

[0019] In some embodiments, and The difference is greater than the minimum capacitance resolution of the SAR sensor, and Greater than the minimum capacitance resolution of the SAR sensor.

[0020] In a second aspect, a packaged chip is also provided. The packaged chip includes a signal isolation module, an impedance matching module, an NFC module, a radio frequency module, and a SAR sensor encapsulated by a packaging structure. The first end of the signal isolation module is connected to the first end of the impedance matching module, and the second end of the impedance matching module is connected to the NFC module. The second end of the signal isolation module is connected to the radio frequency module. The third end of the signal isolation module is connected to the SAR sensor. The fourth end of the signal isolation module is used to connect to the feed point of the antenna. The NFC module is used to perform near-field communication via the antenna. The radio frequency module is used to perform cellular communication via the antenna. The SAR sensor is used to determine the distance between the human body and the antenna via the antenna. The signal isolation module is used to prevent interference between the NFC module, the radio frequency module, and the SAR sensor. In other words, the signal isolation module, impedance matching module, NFC module, radio frequency module, and SAR sensor in the above circuit structure can be packaged into a single chip. In other embodiments, any one or more of the signal isolation module, impedance matching module, NFC module, radio frequency module, and SAR sensor can be packaged into a single chip.

[0021] In a third aspect, an electronic device is provided. The electronic device includes the circuit structure of any one of the first aspects. Alternatively, the electronic device includes an antenna and the packaged chip of the second aspect.

[0022] The technical effects obtained in the above-mentioned second and third aspects are similar to the technical effects obtained by the corresponding technical means in the above-mentioned first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the appearance of a first electronic device in the related art;

[0024] Figure 2 This is a schematic diagram of the appearance of a second electronic device in the related art;

[0025] Figure 3 It is a circuit structure diagram of the first electronic device in the related art;

[0026] Figure 4 It is a structural schematic diagram of an electronic device in the related art;

[0027] Figure 5 This is a circuit structure diagram of a second electronic device in the related art;

[0028] Figure 6 It is a circuit structure diagram of a third electronic device in the related art;

[0029] Figure 7 This is a schematic diagram of a circuit structure provided by an embodiment of the present application;

[0030] Figure 8 This is a working principle diagram of a SAR sensor provided in an embodiment of the present application;

[0031] Figure 9 is an equivalent circuit diagram of the working principle of a SAR sensor provided in an embodiment of the present application;

[0032] Figure 10 This is a schematic structural diagram of a SAR sensor provided in an embodiment of the present application;

[0033] Figure 11 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0034] Figure 12 is a circuit diagram of the first circuit structure provided in an embodiment of the present application;

[0035] Figure 13 is a circuit diagram of a second circuit structure provided in an embodiment of the present application;

[0036] Figure 14 This is an equivalent circuit diagram of the first NFC module, impedance matching module, first inductor, and antenna provided in an embodiment of the present application;

[0037] Figure 15 yes Figure 14 The Smith chart of the equivalent circuit shown when the first electrical signal is input;

[0038] Figure 16 This is an equivalent circuit diagram of the second NFC module, impedance matching module, first inductor, and antenna provided in an embodiment of the present application;

[0039] Figure 17 yes Figure 16 The Smith chart of the equivalent circuit shown when the first electrical signal is input;

[0040] Figure 18 is a circuit diagram of a third circuit structure provided in an embodiment of the present application;

[0041] Figure 19This is an equivalent circuit diagram of the circuit structure of the first SAR sensor provided by the embodiment of the present application when in operation;

[0042] Figure 20 is an equivalent circuit diagram of the circuit structure of the second SAR sensor provided in an embodiment of the present application when in operation;

[0043] Figure 21 This is a circuit diagram of the fourth circuit structure provided in an embodiment of the present application.

[0044] In the related art, the reference numerals represent the following: 10, electronic device; 112, NFC module; 114, NFC antenna; 122, SAR sensor; 124, SAR antenna; 132, RF module; 134, RF antenna;

[0045] The meanings of the figures in the embodiments of the present application are as follows:

[0046] 20. Circuit structure; 210. Signal isolation module; 220. Impedance matching module; 222. First impedance matching module; 224. Second impedance matching module; 230. NFC module; 240. Radio frequency module; 250. SAR sensor; 251. Multiplexing unit; 252. Shielding drive unit; 253. Capacitance-voltage conversion unit; 254. Offset compensation unit; 255. Temperature sensing unit; 256. Operation unit; 257. Analog-to-digital conversion unit; 258. Processing unit; 260. Antenna; 30. Electronic device. DETAILED DESCRIPTION

[0047] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0048] It should be understood that the “multiple” mentioned in this application refers to two or more. In the description of this application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in this article is merely a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in order to facilitate the clear description of the technical solution of this application, words such as “first” and “second” are used to distinguish between identical or similar items with basically the same functions and effects. Those skilled in the art can understand that words such as “first” and “second” do not limit the quantity and execution order, and words such as “first” and “second” do not necessarily limit them to be different.

[0049] Before explaining the circuit structure provided in the embodiment of the present application in detail, the application scenarios and related technologies of the circuit structure are first explained.

[0050] The electronic devices 10 include mobile phones, tablet computers, laptop computers, televisions, wearable devices, etc.; wearable devices include smart watches, wristbands, etc. Figure 1 and Figure 2 1 is a schematic diagram of the appearance of two different electronic devices 10 in the related art. Figure 1 The electronic device 10 shown is a mobile phone. Figure 2 The electronic device 10 shown is a tablet computer. With the rapid development of electronic devices 10, more and more functions are integrated into the electronic devices 10. For example, the electronic device 10 can implement the NFC function.

[0051] NFC is also known as near field communication or short-range wireless communication. "Near field communication" and "near-range wireless communication" here refer to wireless communication at a distance of less than or equal to 10 cm. NFC uses electromagnetic coupling induction technology to provide a short-range wireless connection, thereby enabling two-way interactive communication between electronic device 10 and other electronic devices. Figure 3 FIG. 1 is a circuit diagram of an electronic device 10 in the related art. Figure 3 As shown, to implement the NFC function, the electronic device 10 needs to be provided with an NFC antenna 114 and an NFC module 112 connected to the NFC antenna 114. The NFC module 112 is used to perform electromagnetic coupling induction with other electronic devices through the NFC antenna 114. Figure 4 1 is a schematic diagram of the structure of an electronic device 10 in the related art. Figure 4 As shown, NFC antenna 114 can be a top antenna in a frame antenna of electronic device 10. A frame antenna refers to an antenna integrated with the frame of electronic device 10. The top antenna in a frame antenna refers to the antenna located at the top center of the frame antenna along the paper.

[0052] The SAR value, also known as the Specific Absorption Rate (SAR), refers to the amount of electromagnetic radiation absorbed by a mobile device per unit mass per unit time. The SAR value is an important parameter for measuring the impact of electromagnetic radiation from electronic device 10 on the human body. Lower SAR values ​​indicate less electromagnetic radiation energy absorbed by the human body, while higher SAR values ​​indicate more electromagnetic radiation energy absorbed by the human body. Figure 5 FIG. 1 is a circuit diagram of another electronic device 10 in the related art. Figure 5As shown, in the related art, the electronic device 10 is further provided with a SAR antenna 124 and a SAR sensor 122 connected to the SAR antenna 124. The SAR sensor 122 can use the SAR antenna 124 to determine whether a human body is close to the SAR antenna 124. In other words, the SAR sensor 122 can use the SAR antenna 124 to determine the distance between the human body and the SAR antenna 124. When the electronic device 10 is in operation, the electromagnetic radiation power of the electronic device 10 can be reduced when the distance between the human body and the SAR antenna 124 is less than or equal to a preset distance, thereby reducing the SAR value and reducing the impact of electromagnetic radiation on the human body.

[0053] In related technologies, the electronic device 10 can also implement cellular communication functions. Cellular communication refers to mobile communication using cellular wireless networking, which can provide communication services such as voice, data, and video images via a cellular mobile communication network composed of base stations and the electronic device 10. Figure 6 FIG. 1 is a circuit diagram of another electronic device 10 in the related art. Figure 6 As shown, in the related art, in order to perform cellular communication, the electronic device 10 is further provided with a radio frequency antenna 134 and a radio frequency module 132 connected to the radio frequency antenna 134. The radio frequency module 132 can transmit and receive cellular signals through the radio frequency antenna 134.

[0054] In related art, based on the application scenario requirements of the electronic device 10, the NFC antenna 114 and the SAR antenna 124 may need to be located in the same position. For example, the NFC antenna 114 and the SAR antenna 124 may both need to be the top antenna of the frame antenna of the electronic device 10. In this case, the NFC antenna 114 and the SAR antenna 124 need to be the same antenna. Therefore, how to make the NFC module 112 and the SAR sensor 122 share the same antenna has become an urgent problem that needs to be solved.

[0055] To this end, the embodiments of the present application provide a circuit structure, a packaged chip, and an electronic device. When the circuit structure is applied to an electronic device, the NFC module, the SAR sensor, and the radio frequency module can share an antenna, thereby meeting the requirements of the application scenarios of the electronic device.

[0056] The circuit structure provided in the embodiment of the present application is explained in detail below. In the embodiment of the present application, the connection between two electrical structures (including electrical modules, electrical units, and electronic devices) is an electrical connection. The electrical connection here refers to the ability to transmit electrical signals between the two electrical structures by connection. In addition, the electrical connection between the two electrical structures can be a direct connection via a wire or an indirect connection via other electrical structures.

[0057] Figure 71 is a schematic diagram of a circuit structure 20 provided in an embodiment of the present application. The circuit structure 20 is applied to electronic equipment. Figure 7 As shown, the circuit structure 20 includes a signal isolation module 210 , an impedance matching module 220 , an NFC module 230 , a radio frequency module 240 , a SAR sensor 250 and an antenna 260 .

[0058] The signal isolation module 210 has a first end a, a second end b, a third end c, and a fourth end d. The first end a, second end b, and third end c of the signal isolation module 210 can all transmit electrical signals to the fourth end d of the signal isolation module 210. Furthermore, when any one of the first end a, second end b, and third end c of the signal isolation module 210 transmits an electrical signal to the fourth end d of the signal isolation module 210, the electrical signal will not be transmitted to the other two of the first end a, second end b, and third end c of the signal isolation module 210.

[0059] Antenna 260 is used to receive and transmit radio electromagnetic waves. When antenna 260 is working, it can convert radio electromagnetic waves into electrical signals, thereby achieving the reception of radio electromagnetic waves; it can also convert electrical signals into radio electromagnetic waves, thereby achieving the transmission of radio electromagnetic waves. Antenna 260 has a feeding point, and the feeding point of antenna 260 refers to the connection point where antenna 260 is connected to the feeder. In the embodiment of the present application, the feeding point of antenna 260 is connected to the fourth end d of signal isolation module 210. Antenna 260 can be a frame antenna in an electronic device, or it can be another antenna in the electronic device other than the frame antenna.

[0060] The impedance matching module 220 has a first end e and a second end f. The first end e of the impedance matching module 220 is connected to the first end a of the signal isolation module 210, and the second end f of the impedance matching module 220 is connected to the NFC module 230. In other words, the NFC module 230 is connected to the first end a of the signal isolation module 210 via the impedance matching module 220. Here, the impedance matching module 220 is used to adapt the internal impedance of the NFC module 230 to the external impedance. The external impedance of the NFC module 230 is also referred to as the load impedance. When the internal impedance and external impedance of the NFC module 230 are adapted, signal reflections generated when the NFC module 230 inputs and outputs electrical signals can be suppressed, thereby maximizing the power of the electrical signals input and output by the NFC module 230. In the embodiment of the present application, the NFC module 230 may be an NFC chip.

[0061] That is, the NFC module 230 is connected to the antenna 260 via the second end f, the first end e, the first end a, and the fourth end d of the impedance matching module 220, the signal isolation module 210. For ease of description, in the embodiment of the present application, the electrical signal transmitted between the NFC module 230 and the antenna 260 when the NFC module 230 is working is referred to as the first electrical signal. In this way, when the NFC module 230 is working, the antenna 260 can generate an electromagnetic field by transmitting the first electrical signal to the antenna 260, so that the NFC module 230 can perform electromagnetic coupling induction with other electronic devices through the electromagnetic field generated by the antenna 260 to achieve near field communication. It is understandable that when the first electrical signal is transmitted between the NFC module 230 and the antenna 260, the first electrical signal will not be transmitted to the second end b and the third end c of the signal isolation module 210.

[0062] The RF module 240 has a first terminal g. The first terminal g of the RF module 240 is connected to the second terminal b of the signal isolation module 210 for transmitting cellular signals. Cellular signals are a type of electrical signal. In some embodiments, the RF module 240 may also have a second terminal (not shown). The second terminal of the RF module 240 may be connected to a baseband subsystem in the electronic device. In some specific embodiments, the RF module 240 may include electronic components such as a switch, an antenna tuner, an amplifier, a mixer, a local oscillator (LO), and a filter. Amplifiers include power amplifiers (PAs) and low-noise amplifiers (LNAs). The RF module 240 can be further divided into an RF receive path and an RF transmit path. The RF receive path operates in downlink mode, receiving cellular signals and processing (e.g., amplifying and filtering) the cellular signals to obtain baseband signals, which are then transmitted to the baseband subsystem. The RF transmission channel operates in uplink mode, and is used to receive baseband signals from the baseband subsystem and process the baseband signals (such as amplification and filtering) to obtain cellular signals.

[0063] That is, the first terminal g of the RF module 240 is connected to the antenna 260 via the second terminal b and the fourth terminal d of the signal isolation module 210. Thus, when the RF module 240 is operating, it can transmit cellular signals to the antenna 260, and it can also receive cellular signals transmitted by the antenna 260, thereby achieving cellular communication. It will be appreciated that when cellular signals are transmitted between the RF module 240 and the antenna 260, the cellular signals will not be transmitted to the third terminal c of the signal isolation module 210, nor will they be transmitted to the NFC module 230 via the first terminal a of the signal isolation module 210.

[0064] The SAR sensor 250 has a first terminal h. The first terminal h of the SAR sensor 250 is connected to the third terminal c of the signal isolation module 210. That is, the first terminal h of the SAR sensor 250 is connected to the antenna 260 via the third terminal c and the fourth terminal d of the signal isolation module 210. In this manner, when the SAR sensor 250 is operating, the antenna 260 can determine whether the distance between a human body and the antenna 260 is less than or equal to a preset distance. In some embodiments, the SAR sensor 250 may also have a second terminal (not shown). The second terminal of the SAR sensor 250 can be connected to a system-on-chip (SOC) in an electronic device. When the SAR sensor 250 determines that the distance between a human body and the antenna 260 is less than or equal to the preset distance, i.e., when the human body is close to the antenna 260, the SOC transmits a preset communication signal to the SOC. After receiving the preset communication signal, the SOC can reduce the electromagnetic radiation power of the electronic device. It will be understood that when the SAR sensor 250 determines that the distance between a human body and the antenna 260 is less than or equal to the preset distance via the antenna 260, electrical signals need to be transmitted between the SAR sensor 250 and the antenna 260. For ease of description, in this embodiment of the present application, the electrical signal transmitted between the SAR sensor 250 and the antenna 260 during operation is referred to as the second electrical signal. When the second electrical signal is transmitted between the SAR sensor 250 and the antenna 260, the second electrical signal is neither transmitted to the NFC module 230 via the first end a of the signal isolation module 210, nor is it transmitted to the RF module 240 via the second end b of the signal isolation module 210. Thus, the signal isolation module 210 prevents the NFC module 230, the RF module 240, and the SAR sensor 250 from interfering with each other during operation.

[0065] In an embodiment of the present application, the circuit structure 20 includes a signal isolation module 210, an impedance matching module 220, an NFC module 230, a radio frequency module 240, a SAR sensor 250, and an antenna 260. The NFC module 230, the radio frequency module 240, and the SAR sensor 250 are all connected to the antenna 260 via the signal isolation module 210. Thus, without interfering with each other, the NFC module 230 can perform near-field communication via the antenna 260; the radio frequency module 240 can perform cellular communication via the antenna 260; and the SAR sensor 250 can determine whether the distance between the human body and the antenna 260 is less than or equal to a preset distance via the antenna 260. In other words, the NFC module 230, the radio frequency module 240, and the SAR sensor 250 can share a single antenna 260, which can meet the requirements of the application scenarios of electronic devices.

[0066] It is understood that in some other embodiments of the present application, the circuit structure 20 may not include any of the NFC module 230, the RF module 240, and the SAR sensor 250. When the circuit structure 20 does not include the NFC module 230, it may also not include the impedance matching module 220. For example, in some embodiments, the circuit structure 20 may only include the signal isolation module 210, the impedance matching module 220, the NFC module 230, the RF module 240, and the antenna 260. In other embodiments, the circuit structure 20 may also only include the signal isolation module 210, the RF module 240, the SAR sensor 250, and the antenna 260, which will not be described in detail.

[0067] The principle of the SAR sensor 250 “determining whether the distance between the human body and the antenna 260 is less than or equal to a preset distance through the antenna 260 ” and the structure of the SAR sensor 250 are described below.

[0068] Figure 8 FIG. 2 is a working principle diagram of a SAR sensor 250 provided in an embodiment of the present application. Figure 8 As shown, when the SAR sensor 250 needs to determine through the antenna 260 whether the distance between the human body and the antenna 260 is less than or equal to a preset distance, the SAR sensor 250 can output a second electrical signal to the antenna 260. At this time, the antenna 260 can convert the received second electrical signal into a radio electromagnetic wave and radiate it outward, thereby forming an outwardly radiating electromagnetic field. Figure 8 FIG. 2 (a) shows a schematic diagram of the electromagnetic field radiated outward by the antenna 260 when the distance between the human body and the antenna 260 is greater than a preset distance; Figure 8 Figure (b) shows a schematic diagram of the electromagnetic field radiated outward by the antenna 260 when the distance between the human body and the antenna 260 is less than or equal to the preset distance. Figure 8 As can be seen from Figures (a) and (b) in the figure, since the human body is a conductor, when the human body is close to antenna 260, that is, when the distance between the human body and antenna 260 is less than or equal to the preset distance, it will cause the electromagnetic field radiated outward by antenna 260 to change. Generally, the preset distance can be set by those skilled in the art based on experience and needs. The preset distance can be, for example, 10 cm (centimeter), 15 cm, or 20 cm, which is not limited here.

[0069] Figure 9 FIG. 2 shows an equivalent circuit diagram of the working principle of the SAR sensor 250. Figure 9 Figure (a) is Figure 8 The equivalent circuit of Figure (a) is: Figure 9 Figure (b) is Figure 8 The equivalent circuit of Figure (b) in . Figure 8 Figure (a) and Figure 9As shown in Figure (a), when the distance between the human body and the antenna 260 is greater than the preset distance, only background capacitance CA exists between the first terminal h of the SAR sensor 250 and the ground line GND. Background capacitance CA refers to the capacitance in the environment of the SAR sensor 250 when the SAR sensor 250 is operating. The capacitance value of the background capacitance CA does not change with changes in the distance between the human body and the antenna 260. In this case, the capacitance value of the first terminal h of the SAR sensor 250 is the capacitance value of the background capacitance CA. Figure 8 Figure (b) and Figure 9 As shown in Figure (b), when the distance between the human body and the antenna 260 is less than or equal to the preset distance, the human body's effect on the electromagnetic field radiated outward by the antenna 260 is equivalent to a coupling capacitor CB connected in parallel to the background capacitor CA. In this case, the capacitance value of the first terminal h of the SAR sensor 250 will inevitably change compared to when the distance between the human body and the antenna 260 is greater than the preset distance. Based on this, the SAR sensor 250 can determine whether the distance between the human body and the antenna 260 is less than or equal to the preset distance by detecting the capacitance value of its first terminal h. For example, the SAR sensor 250 may have a preset capacitance value range. When the capacitance value of the first terminal h of the SAR sensor 250 is within the preset capacitance value range, the SAR sensor 250 determines that the distance between the human body and the antenna 260 is less than or equal to the preset distance. Conversely, when the capacitance value of the first terminal h of the SAR sensor 250 is not within the preset capacitance value range, the SAR sensor 250 determines that the distance between the human body and the antenna 260 is greater than the preset distance.

[0070] Based on the above working principle, the structure of the SAR sensor 250 can be as follows: Figure 10 See Figure 10 The SAR sensor 250 includes a multiplexing unit 251, a shield driving unit 252, a capacitance-to-voltage conversion unit 253, an offset compensation unit 254, a temperature sensing unit 255, an operation unit 256, an analog-to-digital conversion unit 257, and a processing unit 258.

[0071] The multiplexing unit 251 has a first port 1, a second port 2, a third port 3, a fourth port 4, a fifth port 5, a sixth port 6, and a seventh port 7. The first port 1, second port 2, third port 3, fourth port 4, and fifth port 5 of the multiplexing unit 251 can all be connected to the antenna 260. "Connecting to the antenna 260" here includes being connected to the third terminal c of the signal isolation module 210, thereby connecting to the antenna 260 via the third terminal c and fourth terminal d of the signal isolation module 210. In other words, the first port 1, second port 2, third port 3, fourth port 4, and fifth port 5 of the multiplexing unit 251 are all first terminals h of the SAR sensor 250. In other embodiments, the multiplexing unit 251 may include only one or more of the first port 1, second port 2, third port 3, fourth port 4, and fifth port 5. The sixth port 6 of the multiplexing unit 251 is connected to the shielding driver unit 252, so that the shielding driver unit 252 can control and drive the shielding component in the multiplexing unit 251, thereby reducing radio frequency interference. The seventh port 7 of the multiplexing unit 251 is connected to the capacitance-voltage conversion unit 253. Here, each of the first port 1, second port 2, third port 3, fourth port 4, and fifth port 5 of the multiplexing unit 251 can be connected to the seventh port 7 of the multiplexing unit 251.

[0072] Taking the example of the first port 1 of the multiplexing unit 251 being connected to the antenna 260 and the first port 1 of the multiplexing unit 251 being connected to the seventh port 7, when the first port 1 of the multiplexing unit 251 is connected to the seventh port 7, the capacitance-to-voltage conversion unit 253 can generate a first voltage signal based on the capacitance value of the first port 1 of the multiplexing unit 251 and output the first voltage signal to the operation unit 256. The first voltage signal is an analog electrical signal. During the process of the capacitance-to-voltage conversion unit 253 generating the first voltage signal based on the capacitance value, the offset compensation unit 254 can also detect and compensate for the offset of the first voltage signal generated by the capacitance-to-voltage conversion unit 253, thereby ensuring the accuracy and stability of the first voltage signal output to the operation unit 256.

[0073] The temperature sensing unit 255 is configured to generate a second voltage signal based on the temperature of the environment in which the SAR sensor 250 is located, and output the second voltage signal to the operation unit 256. The second voltage signal is an analog electrical signal. The operation unit 256 is configured to process the first voltage signal and the second voltage signal. For example, the operation unit 256 may include a programmable gain amplifier for linearly amplifying the first voltage signal and the second voltage signal. The operation unit 256, the analog-to-digital conversion unit 257, and the processing unit 258 are connected in sequence. The analog-to-digital conversion unit 257 is configured to convert the analog electrical signal into a digital electrical signal. In this way, the processing unit 258 can determine the capacitance value of the first port 1 of the multiplexing unit 251 and the temperature of the environment in which the SAR sensor 250 is located based on the received digital electrical signal.

[0074] It is understood that in other embodiments, if the capacitance-to-voltage conversion unit 253 only needs to be connected to one antenna 260, the SAR sensor 250 may not include the multiplexing unit 251 and the shielding driving unit 252. In addition, the SAR sensor 250 may also not include the temperature sensing unit 255, etc., which will not be described in detail.

[0075] Figure 11 This is a schematic diagram of the structure of an electronic device 30 provided in an embodiment of the present application, which includes Figure 10 The SAR sensor 250 is shown. Figure 11 In the electronic device 30 shown, the processing unit 258 in the SAR sensor 250 is a micro control unit (MCU) of the electronic device 30, that is, a single chip microcomputer. Figure 11 As shown, the analog-to-digital conversion unit 257 and the MCU can be connected via an I2C (inter integrated circuit) bus. The MCU can also be connected to an I2C chip, a read-only memory (ROM), and a random access memory (RAM) via the I2C bus. Among them, the RAM includes a code random access memory (CODE RAM) and a data random access memory (DATARAM). The I2C chip also has a first port 1, a second port 2, and a third port 3 connected to other electronic devices, which will not be repeated here.

[0076] The circuit structure 20 provided in the embodiment of the present application is explained in detail below from two possible solutions.

[0077] 1. The first possible solution.

[0078] Figure 12 2 is a circuit diagram of a circuit structure 20 provided in an embodiment of the present application. Figure 12As shown, in some embodiments, the signal isolation module 210 includes a first inductor L1 , a first capacitor C1 , and a second inductor L2 .

[0079] The second end of the first inductor L1, the second plate of the first capacitor C1, and the second end of the second inductor L2 are all connected to the feed point of the antenna 260. In other words, the second end of the first inductor L1, the second plate of the first capacitor C1, and the second end of the second inductor L2 are connected to the same node, which is the fourth end d of the signal isolation module 210, and this node is used to connect to the feed point of the antenna 260. In the following embodiment, for ease of description, the node connected to the second end of the first inductor L1, the second plate of the first capacitor C1, the second end of the second inductor L2, and the feed point of the antenna 260 is referred to as node Q.

[0080] The first end of the first inductor L1 is connected to the first end e of the impedance matching module 220. In other words, the first end of the first inductor L1 corresponds to the first end a of the signal isolation module 210. Here, the first inductor L1 is used to block cellular signals, preventing them from being transmitted to the NFC module 230 via the first end a of the signal isolation module 210 during cellular signal transmission between the RF module 240 and the antenna 260. Similarly, the first inductor L1 is also used to block the second electrical signal, preventing it from being transmitted to the NFC module 230 via the first end a of the signal isolation module 210.

[0081] The first plate of the first capacitor C1 is connected to the first end g of the RF module 240. In other words, the first plate of the first capacitor C1 is the second end b of the signal isolation module 210. Here, the first capacitor C1 is used to block the second electrical signal, so that when the second electrical signal is transmitted between the SAR sensor 250 and the antenna 260, the second electrical signal is not transmitted to the RF module 240 through the second end b of the signal isolation module 210. Similarly, the first capacitor C1 is also used to block the first electrical signal, so that the first electrical signal is not transmitted to the RF module 240 through the second end b of the signal isolation module 210.

[0082] The first end of the second inductor L2 is connected to the first end h of the SAR sensor 250. In other words, the first end of the second inductor L2 corresponds to the third end c of the signal isolation module 210. Here, the second inductor L2 is used to block cellular signals. Therefore, when cellular signals are transmitted between the RF module 240 and the antenna 260, the cellular signals are not transmitted to the SAR sensor 250 via the third end c of the signal isolation module 210. Similarly, the second inductor L2 is also used to block the first electrical signal, preventing it from being transmitted to the SAR sensor 250 via the third end c of the signal isolation module 210.

[0083] It is understandable that in some other embodiments of the present application, the first inductor L1, the first capacitor C1, and the second inductor L2 can all be replaced with other electrical units having the same signal blocking function. For example, the first inductor L1 can be replaced by a first isolation unit, which can be a high-order circuit formed by connecting an inductor and a capacitor in series or in parallel, and is used to block the cellular signal and the second electrical signal. The first capacitor C1 can be replaced by a second isolation unit, which can also be a high-order circuit formed by connecting an inductor and a capacitor in series or in parallel, and is used to block the first electrical signal and the second electrical signal. The second inductor L2 can be replaced by a third isolation unit, which is used to block the cellular signal and the first electrical signal, and will not be described in detail.

[0084] Still like Figure 12 As shown, in some embodiments, the impedance matching module 220 includes a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, and a third inductor L3.

[0085] The first plate of the third capacitor C3 is connected to the first end of the signal isolation module 210, and the first plate of the fourth capacitor C4 is connected to the first end of the signal isolation module 210. In other words, the first plate of the third capacitor C3 and the first plate of the fourth capacitor C4 are connected together to form the first end e of the impedance matching module 220. The second plate of the third capacitor C3 is connected to the ground line GND. The second plate of the fourth capacitor C4 is connected to the first plate of the fifth capacitor C5 and the first end of the third inductor L3. The second plate of the fifth capacitor C5 is connected to the ground line GND. The second end of the third inductor L3 is connected to the NFC module 230. In other words, the second end of the third inductor L3 is the second end f of the impedance matching module 220.

[0086] In this possible solution, the circuit structure 20 should also meet the following condition 1: when the distance between the human body and the antenna 260 is greater than a preset distance, the capacitance value of the feeding point of the antenna 260 is less than or equal to the preset capacitance value.

[0087] Specifically, as mentioned above, the principle of the SAR sensor 250 "determining whether the distance between the human body and the antenna 260 is less than or equal to the preset distance through the antenna 260" is that the SAR sensor 250 determines whether the distance between the human body and the antenna 260 is less than or equal to the preset distance by detecting the capacitance value of its first end h. The capacitor connected to the first end h of the SAR sensor 250 includes the background capacitance CA and the coupling capacitance CB. Among them, the background capacitance CA refers to the capacitance in the environment where the SAR sensor 250 is located when the SAR sensor 250 is working. The capacitance value of the background capacitance CA does not change due to the change of the distance between the human body and the antenna 260. For example, the background capacitance CA includes the capacitive device connected to the first end h of the SAR sensor 250, and also includes the parasitic capacitance in the circuit board where the SAR sensor 250 is set. Figure 12 In the illustrated embodiment, background capacitance CA includes a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5. Coupling capacitance CB refers to the capacitance generated when a human body approaches antenna 260 when the SAR sensor 250 is operating. The capacitance of coupling capacitance CB varies with the distance between the human body and antenna 260. As can be seen, the capacitance of background capacitance CA has a significant impact on the capacitance of the first terminal h of the SAR sensor 250. Therefore, the capacitance of background capacitance CA affects the sensitivity of the SAR sensor 250 in detecting whether the distance between a human body and antenna 260 is less than or equal to a preset distance. Generally, the SAR sensor 250 has a background capacitance threshold. The capacitance of the background capacitance CA connected to the first terminal h of the SAR sensor 250 should be less than or equal to this background capacitance threshold. In the present embodiment, the preset capacitance value refers to the background capacitance threshold of the SAR sensor 250.

[0088] exist Figure 12 In the illustrated embodiment, since only the second inductor L2 is connected between the first terminal h of the SAR sensor 250 and the node Q, the capacitance value of the background capacitor CA connected to the first terminal h of the SAR sensor 250 is equal to the capacitance value of the node Q when the distance between the human body and the antenna 260 is greater than a preset distance. Since the feeding point of the antenna 260 is connected to the node Q, the capacitance value of the background capacitor CA connected to the first terminal h of the SAR sensor 250 is also equal to the capacitance value of the feeding point of the antenna 260 when the distance between the human body and the antenna 260 is greater than the preset distance. Based on this, in this possible solution, when the distance between the human body and the antenna 260 is greater than the preset distance, the capacitance value of the feeding point of the antenna 260 should be less than or equal to the preset capacitance value.

[0089] Easy to understand, in Figure 12 In the embodiment shown, when the distance between the human body and the antenna 260 is greater than a preset distance, the capacitance value of the feeding point of the antenna 260, that is, the capacitance value of the node Q, is determined by the capacitance value of the third capacitor C3, the capacitance value of the fourth capacitor C4 and the capacitance value of the fifth capacitor C5.

[0090] In this possible solution, the antenna 260 , the first inductor L1 , and the impedance matching module 220 should also meet the following condition 2: the external impedance of the NFC module 230 is within a preset impedance range.

[0091] Specifically, as mentioned above, the function of the impedance matching module 220 is to adapt the internal impedance of the NFC module 230 to the external impedance. Figure 12In the illustrated embodiment, the NFC module 230 is connected to the antenna 260 via the impedance matching module 220 and the first inductor L1. That is, the external impedance of the NFC module 230 is affected by the impedance of the impedance matching module 220, the impedance of the first inductor L1, and the impedance of the antenna 260.

[0092] The preset impedance range is the preset external impedance range of the NFC module 230. The preset external impedance range of the NFC module 230 depends on the internal impedance of the NFC module 230. When the external impedance of the NFC module 230 is within the preset impedance range, the internal impedance of the NFC module 230 can be adapted to the external impedance. Therefore, in this possible solution, it is necessary to limit the antenna 260, the first inductor L1, and the impedance matching module 220 so that the external impedance of the NFC module 230 is within the preset impedance range.

[0093] Understandably, in this possible scenario, Figure 12 The circuit structure 20 shown should simultaneously satisfy the above-mentioned conditions 1 and 2. Specifically, the circuit structure 20 can satisfy condition 1 by changing the capacitance values ​​of the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5. However, changing the capacitance values ​​of the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 will inevitably change the impedance of the impedance matching module 220. Based on this, the circuit structure 20 can also satisfy the above-mentioned condition 2 by further adjusting the inductance value of the first inductor L1. For example, the capacitance values ​​of the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 in the impedance matching module 220 are generally in the nF (nanofarad) range. As a result, when the distance between the human body and the antenna 260 is greater than the preset distance, the capacitance value at the feed point of the antenna 260 is also in the nF range. While the preset capacitance value varies depending on the SAR sensor 250, it is generally in the pF (picofarad) range, such as 250pF, 300pF, 600pF, or 700pF. In this case, the capacitance value of the feeding point of the antenna 260 when the distance between the human body and the antenna 260 is greater than the preset distance can be reduced by changing the capacitance value of the third capacitor C3, the capacitance value of the fourth capacitor C4, and the capacitance value of the fifth capacitor C5; and the internal impedance of the NFC module 230 is adapted to the external impedance by increasing the inductance value of the first inductor L1.

[0094] The following takes a case where the preset capacitance value is 700 pF and the preset impedance range is 11Ω (ohms) to 13Ω as an example to explain in detail how the circuit structure 20 satisfies the above conditions 1 and 2 at the same time.

[0095] Figure 13 This is a circuit diagram of another circuit structure 20 provided in an embodiment of the present application. Figure 12 The circuit structure 20 shown, Figure 13 The circuit structure 20 shown does not include the second inductor L2 and the SAR sensor 250. Therefore, Figure 13 The circuit structure 20 shown only needs to satisfy the above condition 2, but does not need to satisfy the above condition 1.

[0096] exist Figure 13 In the circuit structure 20 shown, the capacitance of the first capacitor C1 is in the pF range, for example, between 10 pF and 100 pF. The inductance of the first inductor L1 is 47 nH (nanohenry). The capacitance of the third capacitor C3 is 506 pF. The capacitance of the fourth capacitor C4 is 566 pF. The capacitance of the fifth capacitor C5 is 1522 pF. The inductance of the third inductor L3 is 77 nH. Figure 14 is an equivalent circuit diagram of an NFC module 230, an impedance matching module 220, a first inductor L1, and an antenna 260 provided in an embodiment of the present application, and Figure 14 for Figure 13 The equivalent circuit diagram of the NFC module 230, the impedance matching module 220, the first inductor L1, and the antenna 260 in the circuit structure 20 shown in FIG. Figure 14 In the example, the first resistor R1 is the equivalent resistance to ground of the NFC module 230 and has a resistance of 1Ω. The first equivalent inductor LA includes the first inductor L1 and the equivalent inductor of the antenna 260. The inductance of the first equivalent inductor LA is equal to the sum of the inductance of the first inductor L1 and the inductance of the equivalent inductor of the antenna 260. The inductance of the equivalent inductor of the antenna 260 is 103 nH, so the inductance of the first equivalent inductor LA is 150 nH.

[0097] The frequency range of the first electrical signal is generally between 1 MHz (megahertz) and 20 MHz. Figure 15 yes Figure 14 The equivalent circuit shown is a Smith chart when the first electrical signal with a frequency of 13.56 MHz is input. Figure 15 It can be seen that when the frequency of the first electrical signal is 13.56 MHz, the impedance of the circuit composed of the antenna 260, the first inductor L1, and the impedance matching module 220 (ie, the external impedance of the NFC module 230) is 11.997-j0.029 Ω. In other words, the external impedance of the NFC module 230 is about 12 Ω, so Figure 13 The circuit configuration 20 shown satisfies the above-mentioned condition 2.

[0098] exist Figure 13 and Figure 14 In the embodiment shown, the relationship between the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 is as follows: the fourth capacitor C4 and the fifth capacitor C5 are connected in series, and then connected in parallel with the third capacitor C3. Based on this, when the distance between the human body and the antenna 260 is greater than the preset distance, the capacitance value of the node Q is:

[0099]

[0100] Among them, C Q is the capacitance value of the node Q, in pF, C3 is the capacitance value of the third capacitor C3, C4 is the capacitance value of the fourth capacitor C4, and C5 is the capacitance value of the fifth capacitor C5.

[0101] That is, when the distance between the human body and the antenna 260 is greater than the preset distance, the capacitance value of the feed point of the antenna 260 is 918.573 pF, which is greater than the preset capacitance value. In this case, the SAR sensor 250 cannot be directly connected to the node Q through the second inductor L2.

[0102] In this solution, by increasing the inductance of the first inductor L1 and changing the capacitance of the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5, when the distance between the human body and the antenna 260 is greater than the preset distance, the capacitance of the feeding point of the antenna 260 is less than the preset capacitance. In this way, the SAR sensor 250 can be connected to the node Q through the second inductor L2, thereby obtaining Figure 12 The circuit structure 20 is shown.

[0103] Figure 12 The capacitance value of the first capacitor C1 in the circuit structure 20 shown is Figure 13 The capacitance values ​​of the first capacitors C1 in the circuit structure 20 shown are the same. Figure 12 In the circuit structure 20 shown, the inductance of the first inductor L1 is 97nH. Figure 13 The inductance of the first inductor L1 in FIG1 is increased by 50 nH. The inductance of the second inductor L2 is 82 nH. The capacitance of the third capacitor C3 is 364 pF. The capacitance of the fourth capacitor C4 is 407 pF. The capacitance of the fifth capacitor C5 is 1597 pF. The inductance of the third inductor L3 is 77 nH. Figure 16 is an equivalent circuit diagram of another NFC module 230, impedance matching module 220, first inductor L1, and antenna 260 provided in an embodiment of the present application, and Figure 16 for Figure 12 The equivalent circuit diagram of the NFC module 230, the impedance matching module 220, the first inductor L1, and the antenna 260 in the circuit structure 20 shown in FIG. Figure 16In the example, the first resistor R1 is the equivalent resistance to ground of the NFC module 230 and has a resistance of 1Ω. The second equivalent inductor LB includes the first inductor L1 and the equivalent inductor of the antenna 260. The inductance of the second equivalent inductor LB is equal to the sum of the inductance of the first inductor L1 and the inductance of the equivalent inductor of the antenna 260. The inductance of the equivalent inductor of the antenna 260 is 103 nH, so the inductance of the second equivalent inductor LB is 200 nH.

[0104] Figure 17 yes Figure 16 The equivalent circuit shown is a Smith chart when the first electrical signal with a frequency of 13.56 MHz is input. Figure 17 It can be seen that when the frequency of the first electrical signal is 13.56 MHz, the impedance of the circuit composed of the antenna 260, the first inductor L1, and the impedance matching module 220 (i.e., the external impedance of the NFC module 230) is 11.991 + j0.135 Ω. In other words, in this case, the external impedance of the NFC module 230 is still about 12 Ω, so Figure 12 The circuit configuration 20 shown satisfies the above-mentioned condition 2.

[0105] exist Figure 12 and Figure 16 In the embodiment shown, the capacitance of node Q is:

[0106]

[0107] C Q The unit is pF. That is, when the distance between the human body and the antenna 260 is greater than the preset distance, the capacitance value of the feeding point of the antenna 260 is 688.341 pF, which is less than the preset capacitance value. Therefore, the circuit structure 20 also meets the above condition 1.

[0108] It is understood that in the embodiment of the present application, to increase the inductance of the first inductor L1, the first inductor L1 can be replaced with an inductor with a higher inductance. Alternatively, the first inductor L1 can include multiple sub-inductors connected in series. To increase the inductance of the first inductor L1, the number of sub-inductors connected in series in the first inductor L1 can be increased or the sub-inductors can be replaced with inductors with a higher inductance.

[0109] 2. The second possible solution.

[0110] Figure 18 2 is a circuit diagram of another circuit structure 20 provided in an embodiment of the present application. Figure 18 As shown, in some embodiments, the signal isolation module 210 includes a first inductor L1, a first capacitor C1, a second inductor L2, and a second capacitor C2. The circuit structure 20 in this embodiment is compared to Figure 12The circuit structure 20 shown is newly provided with a second capacitor C2 , and the second end of the second inductor L2 is connected to the feeding point of the antenna 260 via the second capacitor C2 .

[0111] Specifically, the second end of the first inductor L1, the second plate of the first capacitor C1, and the second plate of the second capacitor C2 are all connected to the feed point of the antenna 260. In other words, the second end of the first inductor L1, the second plate of the first capacitor C1, and the second plate of the second capacitor C2 are connected to the same node, which is the fourth end d of the signal isolation module 210, and the node is used to connect to the feed point of the antenna 260. In the following embodiments, for ease of description, the node to which the second end of the first inductor L1, the second plate of the first capacitor C1, the second plate of the second capacitor C2, and the feed point of the antenna 260 are connected is still referred to as node Q.

[0112] The first end of the first inductor L1 is connected to the first end e of the impedance matching module 220. The first inductor L1 is used to block cellular signals and second electrical signals. The first plate of the first capacitor C1 is connected to the first end g of the RF module 240. The first capacitor C1 is used to block the second electrical signal and the first electrical signal. The first end of the second inductor L2 is connected to the first end h of the SAR sensor 250. The second end of the second inductor L2 is connected to the first plate of the second capacitor C2. Here, the second inductor L2 and the second capacitor C2 are used to block cellular signals and the first electrical signal.

[0113] In this embodiment, Figure 18 As shown, the impedance matching module 220 also includes a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, and a third inductor L3. Figure 18 In the embodiment shown, the connection relationship of the electronic components (including the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, and the third inductor L3) in the impedance matching module 220 is compared with Figure 12 、 Figure 13 As shown, no changes have occurred, so the connection relationship of each electronic device is not repeated. It is easy to understand that in some other embodiments, the impedance matching module 220 can also include more or fewer capacitors and inductors, and this embodiment of the application does not limit this.

[0114] In this possible solution, the circuit structure 20 should also meet the following condition 3: when the distance between the human body and the antenna 260 is greater than a preset distance, the capacitance value of the first terminal h of the SAR sensor 250 is less than or equal to the preset capacitance value.

[0115] Specifically, as described above, the capacitor connected to the first terminal h of the SAR sensor 250 includes a background capacitor CA and a coupling capacitor CB. The capacitance of the background capacitor CA should be as small as possible. In this embodiment of the present application, the capacitance of the background capacitor CA should be less than or equal to a preset capacitance value. The preset capacitance value is the background capacitance threshold of the SAR sensor 250. That is, when the distance between the human body and the antenna 260 is greater than the preset distance, i.e., when the coupling capacitor CB is absent, the capacitance of the first terminal h of the SAR sensor 250 should be less than or equal to the preset capacitance value. In this embodiment, the first terminal h of the SAR sensor 250 can also be referred to as the connection point between the SAR sensor 250 and the first end of the second inductor L2. Therefore, condition 3 can also be expressed as: when the distance between the human body and the antenna 260 is greater than the preset distance, the capacitance of the connection point between the SAR sensor 250 and the first end of the second inductor L2 is less than or equal to the preset capacitance value.

[0116] Easy to understand, in Figure 18 In the illustrated embodiment, the capacitance value of the first terminal h of the SAR sensor 250 when the distance between the human body and the antenna 260 is greater than a predetermined distance, that is, the capacitance value of the background capacitor CA connected to the first terminal h of the SAR sensor 250, is determined by the capacitance values ​​of the second capacitor C2, the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5.

[0117] In this possible solution, the antenna 260 , the first inductor L1 , and the impedance matching module 220 should also meet the above condition 2: ensuring that the external impedance of the NFC module 230 is within a preset impedance range.

[0118] It is understandable that in this possible solution, the circuit structure 20 should simultaneously satisfy the above-mentioned conditions 3 and 2. Specifically, the circuit structure 20 can satisfy the above-mentioned condition 3 by setting the capacitance value of the second capacitor C2, based on the circuit structure 20 satisfying the above-mentioned condition 2. For example, the capacitance values ​​of the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 in the impedance matching module 220 are generally in the nF range. As a result, when the distance between the human body and the antenna 260 is greater than the preset distance, the capacitance value of the first terminal h of the SAR sensor 250 is also in the nF range. The preset capacitance value is generally in the pF range, such as 250pF, 300pF, 600pF, or 700pF. In this case, the capacitance value of the second capacitor C2 can be set to reduce the capacitance value of the first terminal h of the SAR sensor 250 when the distance between the human body and the antenna 260 is greater than the preset distance.

[0119] The following takes a preset capacitance value of 700 pF and a preset impedance range of 11Ω to 13Ω as an example to explain in detail how the circuit structure 20 satisfies both the above conditions 3 and 2.

[0120] Will Figure 18 The circuit structure 20 shown is Figure 13 The circuit structure 20 shown is compared. Figure 13 The circuit structure 20 shown does not include the second inductor L2, the second capacitor C2 and the SAR sensor 250. Therefore, Figure 13 The circuit structure 20 shown only needs to satisfy the above condition 2, but does not need to satisfy the above condition 3.

[0121] exist Figure 13 In the circuit structure 20 shown, the capacitance value of the first capacitor C1 is in the order of pF, for example, the capacitance value of the first capacitor C1 is between 10pF and 100pF. The inductance value of the first inductor L1 is 47nH. The capacitance value of the third capacitor C3 is 506pF. The capacitance value of the fourth capacitor C4 is 566pF. The capacitance value of the fifth capacitor C5 is 1522pF. The inductance value of the third inductor L3 is 77nH. The inductance value of the equivalent inductance of the antenna 260 is 103nH. Based on the Figures 13 to 15 According to the analysis, in this case, the external impedance of the NFC module 230 is 11.997-j0.029Ω, so Figure 13 The circuit structure 20 shown satisfies the aforementioned condition 2. The capacitance value of node Q is 918.573 pF, which is greater than the preset capacitance value. In this case, if the SAR sensor 250 is directly connected to node Q via the second inductor L2, the capacitance value of the first terminal h of the SAR sensor 250 will be 918.573 pF, which is greater than the preset capacitance value, when the distance between the human body and the antenna 260 is greater than the preset distance. Therefore, the SAR sensor 250 cannot be directly connected to node Q via the second inductor L2.

[0122] In this solution, by connecting the second capacitor C2 in series between the second inductor L2 and the node Q, the inductance value of the first inductor L1, the capacitance value of the third capacitor C3, the capacitance value of the fourth capacitor C4, and the capacitance value of the fifth capacitor C5 are not changed. In this way, the capacitance value of the first terminal h of the SAR sensor 250 can be reduced when the distance between the human body and the antenna 260 is greater than the preset distance, and the external impedance of the NFC module 230 will not be changed, that is, it will not affect the circuit structure 20 from satisfying condition 2.

[0123] For example, in Figure 18 In the circuit structure 20 shown, the capacitance value of the second capacitor C2 can be 1000pF, and the inductance value of the second inductor L2 can be 82nH. The capacitance value of the first capacitor C1, the inductance value of the first inductor L1, the capacitance value of the third capacitor C3, the capacitance value of the fourth capacitor C4, the capacitance value of the fifth capacitor C5, the inductance value of the third inductor L3, and the inductance value of the equivalent inductance of the antenna 260 are relative to Figure 13The circuit structure 20 shown remains unchanged. That is, the inductance of the first inductor L1 remains 47nH. The capacitance of the third capacitor C3 remains 506pF. The capacitance of the fourth capacitor C4 remains 566pF. The capacitance of the fifth capacitor C5 remains 1522pF. The inductance of the third inductor L3 remains 77nH. The inductance of the equivalent inductor of the antenna 260 remains 103nH. In this case, the external impedance of the NFC module 230 remains 11.997-j0.029Ω, so Figure 18 The circuit configuration 20 shown satisfies the above-mentioned condition 2.

[0124] The second capacitor C2 and the node Q are in series connection. Based on this, when the distance between the human body and the antenna 260 is greater than the preset distance, the capacitance value of the first terminal h of the SAR sensor 250 is:

[0125]

[0126] Among them, C SAR is the capacitance value (in pF) at the first terminal h of the SAR sensor 250 when the distance between the human body and the antenna 260 is greater than the preset distance. C2 is the capacitance value of the second capacitor C2. That is, after the second capacitor C2 is connected in series between the second inductor L2 and the node Q, the capacitance value at the first terminal h of the SAR sensor 250 when the distance between the human body and the antenna 260 is greater than the preset distance is 478.799 pF, which is less than the preset capacitance value. Therefore, this circuit structure 20 also meets the aforementioned condition 3.

[0127] It is understood that the capacitance value of the second capacitor C2 depends on the background capacitance threshold of the SAR sensor 250 and the capacitance value of the node Q when the distance between the human body and the antenna 260 is greater than the preset distance. Therefore, the capacitance value of the second capacitor C2 can be set by those skilled in the art based on experience and needs. Generally, the capacitance value of the second capacitor C2 is greater than or equal to 100 pF, and the capacitance value of the second capacitor C2 is less than or equal to 10nF. For example, the capacitance value of the second capacitor C2 can be 100pF, 500pF, 1nF, 5nF or 10nF.

[0128] It should be noted that in this solution, although the second capacitor C2 can be added Figure 18 The circuit structure 20 shown satisfies the above condition 3. However, compared with the case where the second capacitor C2 is not added, the capacitance value of the first terminal h of the SAR sensor 250 is reduced when the distance between the human body and the antenna 260 remains unchanged.

[0129] Figure 19 This is an equivalent circuit diagram of a circuit structure 20 of a SAR sensor 250 provided in an embodiment of the present application when working, which shows Figure 18The circuit structure 20 shown is an equivalent circuit of the SAR sensor 250 when the distance between the human body and the antenna 260 is greater than the preset distance. Figure 19 As shown, in this case, the capacitor connected to the first terminal h of the SAR sensor 250 includes the second capacitor C2 and the node capacitor CQ. The node capacitor CQ refers to the capacitance of the node Q, that is, the capacitance between the feeding point of the antenna 260 and the ground line GND. In this case, the capacitance value of the first terminal h of the SAR sensor 250 is:

[0130]

[0131] Figure 20 is an equivalent circuit diagram of another SAR sensor 250 provided in an embodiment of the present application when the circuit structure 20 is working, which shows Figure 18 The circuit structure 20 shown is an equivalent circuit of the SAR sensor 250 when the distance between the human body and the antenna 260 is a first distance and the first distance is less than or equal to the preset distance. Figure 20 As shown, in this case, the capacitor connected to the first terminal h of the SAR sensor 250 includes the second capacitor C2, the node capacitor CQ, and the coupling capacitor CB. The coupling capacitor CB refers to the capacitance formed by the coupling between the human body and the antenna 260 when the distance between the human body and the antenna 260 is the first distance. In this case, the capacitance value of the first terminal h of the SAR sensor 250 is:

[0132]

[0133] Among them, C SAR ' is the capacitance value of the first terminal h of the SAR sensor 250 when the distance between the human body and the antenna 260 is the first distance. ΔC is the capacitance value of the coupling capacitor CB.

[0134] It can be seen from this that for Figure 18 In the circuit structure 20 shown in FIG. 2 , when the distance between the human body and the antenna 260 is the first distance, the change in the capacitance value of the first terminal h of the SAR sensor 250 is:

[0135]

[0136] Generally, the capacitance of node Q is much larger than that of coupling capacitor CB. Therefore:

[0137]

[0138] It can be seen from this that for Figure 18In the circuit structure 20 shown, that is, when the second capacitor C2 is connected in series between the second inductor L2 and the node Q, the change in the capacitance value of the first terminal h of the SAR sensor 250 is about 0.01mm / s. Since ΔC is the capacitance value of the coupling capacitor CB, it can be seen that after the second capacitor C2 is connected in series between the second inductor L2 and the node Q, the change rate of the capacitance detected by the first terminal h of the SAR sensor 250 is the original value. In this case, the threshold value of the preset capacitance value range set in the SAR sensor 250 should also be changed to the original This ensures that the SAR sensor 250 can normally detect whether the distance between the human body and the antenna 260 is less than or equal to the preset distance, thereby ensuring the sensitivity of the SAR sensor 250 in detecting the approach of the human body.

[0139] Specifically, for example Figure 5 In the circuit structure shown, that is, the first terminal h of the SAR sensor 250 is directly connected to the antenna 260, the SAR sensor 250 can be provided with a second preset capacitance value range. The second preset capacitance value range is [ΔC min , ΔC max ]. Where, ΔC min is the minimum value of the second preset capacitance value range, ΔC max is the maximum value of the second preset capacitance value range. When the distance between the human body and the antenna 260 is less than or equal to the preset distance, the capacitance value of the first end h of the SAR sensor 250 is within the second preset capacitance value range; conversely, when the distance between the human body and the antenna 260 is greater than the preset distance, the capacitance value of the first end h of the SAR sensor 250 is not within the second preset capacitance value range. For example, when the distance between the human body and the antenna 260 is the first distance, the capacitance value of the first end h of the SAR sensor 250 is ΔC1. The first distance is less than the preset distance, and ΔC1 is within [ΔC min , ΔC max When the distance between the human body and the antenna 260 is the second distance, the capacitance value of the first terminal h of the SAR sensor 250 is ΔC2. The second distance is greater than the preset distance, and ΔC2 is not within [ΔC min , ΔC max The case where “the first end h of the SAR sensor 250 is directly connected to the antenna 260” may also be referred to as “the SAR sensor 250 is only connected to the antenna 260”.

[0140] And for Figure 18 In the circuit structure 20 shown in FIG. 2 , that is, in the case where the circuit structure 20 includes the second capacitor C2, the rate of change of the capacitance detected by the first terminal h of the SAR sensor 250 is the original value. Therefore, when the distance between the human body and the antenna 260 is the first distance, the capacitance value of the first terminal h of the SAR sensor 250 is When the distance between the human body and the antenna 260 is the second distance, the capacitance value of the first terminal h of the SAR sensor 250 is In this case, to ensure that the SAR sensor 250 can normally detect whether the distance between the human body and the antenna 260 is less than or equal to the preset distance, the minimum value of the preset capacitance value range in the SAR sensor 250 should be The maximum value should be Here, the preset capacitance value range, i.e. It is called the first preset capacitance value range. That is, Figure 18 In the illustrated circuit structure 20, the SAR sensor 250 uses a first preset capacitance value range to determine whether the distance between the human body and the antenna 260 is less than or equal to the preset distance. When the capacitance value of the first terminal h of the SAR sensor 250 is within the first preset capacitance value range, the SAR sensor 250 determines that the distance between the human body and the antenna 260 is less than or equal to the preset distance. Conversely, when the capacitance value of the first terminal h of the SAR sensor 250 is not within the first preset capacitance value range, the SAR sensor 250 determines that the distance between the human body and the antenna 260 is greater than the preset distance.

[0141] For example, if the first terminal h of the SAR sensor 250 is directly connected to the antenna 260, the second preset capacitance value range set by the SAR sensor 250 is [55.5×10 -6 pF, 8.2pF]. The capacitance between the feeding point of the antenna 260 (i.e., node Q) and the ground line GND is 2nF, and the capacitance of the second capacitor C2 is 600pF. Therefore, the first preset capacitance value range should be [4.58×10 -6 pF, 0.677pF].

[0142] It is easy to understand that in this embodiment, and The difference should be greater than the minimum capacitance resolution of the SAR sensor 250; and, It should also be greater than the minimum capacitance resolution of the SAR sensor 250. The minimum capacitance resolution of the SAR sensor 250 refers to the minimum capacitance change that can be detected by the SAR sensor 250 when it is working. In other words, there is:

[0143]

[0144] Wherein, ΔF is the minimum capacitance resolution of the SAR sensor 250 .

[0145] It is understood that in the embodiment of the present application, the circuit structure 20 may also include both of the above-mentioned possible solutions. In this case, on the one hand, a second capacitor C2 is provided between the second inductor L2 and the node Q. On the other hand, the capacitance of the feeding point of the antenna 260 can be reduced when the distance between the human body and the antenna 260 is greater than a preset distance by increasing the inductance of the first inductor L1 and changing the capacitance of the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5, thereby reducing the capacitance of the background capacitor CA of the SAR sensor 250.

[0146] exist Figure 12 、 Figure 13 、 Figure 18 In the circuit structure 20 shown, the NFC modules 230 are all single-ended devices, that is, the NFC modules 230 are connected to the feeding point (ie, node Q) of the antenna 260 only through one impedance matching module 220 and one first inductor L1. Figure 21 2 is a circuit diagram of another circuit structure 20 provided in an embodiment of the present application. Figure 21 As shown, in some other embodiments, the NFC module 230 may also be a two-terminal device. In this case, the circuit structure 20 may include two impedance matching modules 220 (i.e., a first impedance matching module 222 and a second impedance matching module 224) and two first inductors L1 (i.e., inductor L11 and inductor L12). The first terminal j of the NFC module 230 is connected to the feed point of the antenna 260 via the first impedance matching module 222 and the inductor L11; the second terminal k of the NFC module 230 is connected to the feed point of the antenna 260 via the second impedance matching module 224 and the inductor L12. The first impedance matching module 222 includes capacitors C31, C41, C51, and inductor L31; the second impedance matching module 224 includes capacitors C32, C42, C52, and inductor L32. The structure of the first impedance matching module 222 is identical to that of the second impedance matching module 224 and will not be further described.

[0147] In the circuit structure 20 provided in the embodiment of the present application, any one or more electrical structures can be encapsulated within the packaging structure to form a packaged chip. In other words, any one or more of the signal isolation module 210, impedance matching module 220, NFC module 230, RF module 240, SAR sensor 250, and antenna 260 can be packaged into a single chip within the packaging structure.

[0148] The present application also provides a packaged chip. The packaged chip includes a signal isolation module 210, an impedance matching module 220, an NFC module 230, a radio frequency module 240, and a SAR sensor 250, which are encapsulated by a packaging structure. The first end of the signal isolation module 210 is connected to the first end of the impedance matching module 220, and the second end of the impedance matching module 220 is connected to the NFC module 230. The second end of the signal isolation module 210 is connected to the radio frequency module 240. The third end of the signal isolation module 210 is connected to the SAR sensor 250. The fourth end of the signal isolation module 210 is connected to the feed point of the antenna 260. The NFC module 230 is used for near-field communication via the antenna 260. The radio frequency module 240 is used for cellular communication via the antenna 260. The SAR sensor 250 is used to determine, via the antenna 260, whether the distance between the human body and the antenna 260 is less than or equal to a preset distance. The signal isolation module 210 is used to prevent interference between the NFC module 230, the radio frequency module 240, and the SAR sensor 250. That is to say, the electrical structures other than the antenna 260 in the above circuit structure 20 can be packaged into one chip.

[0149] An embodiment of the present application further provides an electronic device, which includes the circuit structure 20 or the packaged chip in any one of the above embodiments.

[0150] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. 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. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A circuit structure, characterized in that: The circuit structure includes: a signal isolation module, an impedance matching module, an NFC module, a radio frequency module, a SAR sensor, and an antenna; The first end of the signal isolation module is connected to the first end of the impedance matching module, and the second end of the impedance matching module is connected to the NFC module; the second end of the signal isolation module is connected to the radio frequency module; the third end of the signal isolation module is connected to the SAR sensor; and the fourth end of the signal isolation module is connected to the feeding point of the antenna; The NFC module is used to perform near-field communication through the antenna; the radio frequency module is used to perform cellular communication through the antenna; the SAR sensor is used to determine the distance between the human body and the antenna in the circuit structure through the antenna; and the signal isolation module is used to prevent interference between the NFC module, the radio frequency module, and the SAR sensor.

2. The circuit structure according to claim 1, wherein: The signal isolation module includes: a first inductor, a first capacitor, and a second inductor; The first end of the first inductor is connected to the first end of the impedance matching module; the first plate of the first capacitor is connected to the radio frequency module; the first end of the second inductor is connected to the SAR sensor; The second end of the first inductor, the second plate of the first capacitor, and the second end of the second inductor are all connected to the feeding point.

3. The circuit structure according to claim 2, wherein: The capacitance value of the feeding point is less than or equal to a preset capacitance value, and the preset capacitance value is a background capacitance threshold of the SAR sensor.

4. The circuit structure according to claim 3, wherein: The antenna, the first inductor, and the impedance matching module meet the following condition: the external impedance of the NFC module is within a preset impedance range, and the preset impedance range is a preset external impedance range of the NFC module.

5. The circuit structure according to any one of claims 2 to 4, characterized in that: The signal isolation module further includes: a second capacitor; The first plate of the second capacitor is connected to the second end of the second inductor, and the second plate of the second capacitor is connected to the feeding point.

6. The circuit structure according to claim 5, wherein: A capacitance value at a connection point between the SAR sensor and the first end of the second inductor is less than or equal to a preset capacitance value, where the preset capacitance value is a background capacitance threshold of the SAR sensor.

7. The circuit structure according to claim 6, wherein: The capacitance value of the second capacitor is greater than or equal to 100 pF, and the capacitance value of the second capacitor is less than or equal to 10 nF.

8. The circuit structure according to claim 6 or 7, wherein: The SAR sensor has a first preset capacitance value range, and the first preset capacitance value range is used to determine that the distance between the human body and the antenna in the circuit structure is less than or equal to the preset distance; the minimum value of the first preset capacitance value range is The maximum value of the first preset capacitance value range is Among them, C Q is the capacitance between the feeding point and the ground line, C2 is the capacitance of the second capacitor; ΔC min is the minimum value of the second preset capacitance value range, ΔC max is the maximum value of a second preset capacitance value range, and the second preset capacitance value range is used to determine that the distance between the human body and the antenna is less than or equal to the preset distance when the SAR sensor is connected only to the antenna.

9. The circuit structure according to claim 8, wherein: and The difference is greater than the minimum capacitance resolution of the SAR sensor, and Greater than the minimum capacitance resolution of the SAR sensor.

10. The circuit structure according to any one of claims 1 to 9, characterized in that: The impedance matching module includes: a third capacitor, a fourth capacitor, a fifth capacitor, and a third inductor; The first plate of the third capacitor is connected to the first end of the signal isolation module, and the second plate of the third capacitor is connected to the ground wire; the first plate of the fourth capacitor is connected to the first end of the signal isolation module, and the second plate of the fourth capacitor is connected to the first plate of the fifth capacitor and the first end of the third inductor; the second plate of the fifth capacitor is connected to the ground wire; and the second end of the third inductor is connected to the NFC module.

11. A packaged chip, characterized in that: The packaged chip includes: a signal isolation module, an impedance matching module, an NFC module, a radio frequency module, and a SAR sensor; The first end of the signal isolation module is connected to the first end of the impedance matching module, and the second end of the impedance matching module is connected to the NFC module; the second end of the signal isolation module is connected to the radio frequency module; the third end of the signal isolation module is connected to the SAR sensor; and the fourth end of the signal isolation module is used to connect to the feeding point of the antenna; The NFC module is used to perform near-field communication through the antenna; the radio frequency module is used to perform cellular communication through the antenna; the SAR sensor is used to determine the distance between the human body and the antenna through the antenna; and the signal isolation module is used to prevent the NFC module, the radio frequency module, and the SAR sensor from interfering with each other.

12. An electronic device, characterized in that: The electronic device includes the circuit structure according to any one of claims 1 to 10; or, the electronic device includes an antenna and the packaged chip according to claim 11.

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