Impedance detection circuit and electronic device

Abstract

The invention discloses an impedance detection circuit and electronic equipment, and the impedance detection circuit comprises a transmission line which comprises an antenna end and a radio frequency source end; the at least three voltage coupling detection probes are sequentially arranged along the extension direction of the transmission line and are used for coupling and collecting radio frequency signals transmitted by the transmission line; the voltage sampling circuit is connected with the voltage coupling detection probe and is used for acquiring the radio-frequency signal acquired by the voltage coupling detection probe and converting the radio-frequency signal into corresponding direct-current voltage information; and the processing unit is connected with the voltage sampling circuit and is used for receiving the direct-current voltage information and determining complex impedance of the transmission line according to the direct-current voltage information.

Description

Technical Field

[0001] This application belongs to the field of electronic equipment technology, specifically relating to an impedance detection circuit and an electronic device. Background Technology

[0002] Currently, radio frequency (RF) and antenna mismatch refers to the mismatch between the RF signal transmission system and the antenna. Mismatch problems can lead to reduced communication performance and power amplifier failure.

[0003] In related technologies, some mismatch detection methods are obtained by calculating antenna efficiency. This requires testing the entire device's OTA (Over-the-Air) performance and antenna efficiency during the testing process, which is time-consuming and demands high consistency between RF conducted signal testing instruments and antenna testing instruments. Furthermore, once the electronic equipment is shipped, mismatch cannot be monitored. Subsequent mismatch detection can only be analyzed by testing the after-sales service unit. If large-scale mismatch occurs, the extent of the mismatch cannot be determined to take appropriate measures. Additionally, existing integrated detection solutions using devices such as directional couplers and circulators can only obtain single-point power scalar information, failing to accurately reflect the impedance state of the transmission line. This leads to subsequent tuning relying on inefficient exhaustive traversal, increasing the difficulty of tuning. Summary of the Invention

[0004] This application aims to provide an impedance detection circuit and electronic device that at least solves the problem of difficulty in impedance detection and increased tuning difficulty in related technologies.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] In a first aspect, embodiments of this application propose an impedance detection circuit, comprising: a transmission line, including an antenna end and a radio frequency source end; at least three voltage coupling detection probes, arranged sequentially along the extension direction of the transmission line, for coupling and acquiring radio frequency signals transmitted by the transmission line; a voltage sampling circuit, connected to the voltage coupling detection probes, for acquiring the radio frequency signals acquired by the voltage coupling detection probes and converting them into corresponding DC voltage information; and a processing unit, connected to the voltage sampling circuit, for receiving the DC voltage information and determining the complex impedance of the transmission line based on the DC voltage information.

[0007] Secondly, embodiments of this application provide an electronic device including an impedance detection circuit as described in any of the first aspects.

[0008] In the embodiments of this application, the impedance detection circuit includes a transmission line, at least three voltage coupling detection probes, a voltage sampling circuit, and a processing unit. The transmission line includes an antenna end and a radio frequency (RF) source end for carrying RF signal transmission. At least three voltage coupling detection probes are disposed at different positions along the extension direction of the transmission line in a non-contact manner. These voltage coupling detection probes collect the RF signals transmitted through the transmission line. The voltage sampling circuit is electrically connected to all voltage coupling detection probes, acquires the RF signal collected by each probe, and converts the RF signal into corresponding DC voltage information. The processing unit is connected to the voltage sampling circuit and receives the DC voltage information output by the voltage sampling circuit. Based on the DC voltage information from multiple positions, the complex impedance value on the transmission line can be effectively and accurately detected. In the embodiments proposed in this application, reliable detection of complex impedance is achieved by setting voltage coupling detection probes, which helps reduce costs, has a fast response time, high detection accuracy, and minimal impact on the transmission line.

[0009] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0010] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0011] Figure 1 This is one of the structural schematic diagrams of an impedance detection circuit according to an embodiment of this application;

[0012] Figure 2 This is one of the structural schematic diagrams of a voltage coupling detection probe according to an embodiment of this application;

[0013] Figure 3 This is one of the structural schematic diagrams of the voltage coupling detection probe and transmission line according to an embodiment of this application;

[0014] Figure 4 This is one of the isolation test diagrams between the voltage coupling detection probe and the transmission line according to an embodiment of this application;

[0015] Figure 5 This is a second schematic diagram of the structure of the voltage coupling detection probe according to an embodiment of this application;

[0016] Figure 6 This is a second schematic diagram of the structure of the voltage coupling detection probe and transmission line according to an embodiment of this application;

[0017] Figure 7 This is the second test diagram of the isolation between the voltage coupling detection probe and the transmission line according to the embodiments of this application;

[0018] Figure 8 This is the third schematic diagram of the voltage coupling detection probe according to an embodiment of this application;

[0019] Figure 9 This is the third schematic diagram of the structure of the voltage coupling detection probe and transmission line according to the embodiments of this application;

[0020] Figure 10 This is the third diagram of the isolation test between the voltage coupling detection probe and the transmission line according to the embodiments of this application;

[0021] Figure 11 This is a second schematic diagram of the impedance detection circuit according to an embodiment of this application;

[0022] Figure 12 This is the third schematic diagram of the impedance detection circuit according to an embodiment of this application;

[0023] Figure 13 This is the fourth schematic diagram of the impedance detection circuit according to an embodiment of this application;

[0024] Figure 14 This is a circuit diagram of an electronic device according to an embodiment of this application;

[0025] Figure 15 This is a schematic block diagram of an electronic device according to an embodiment of this application.

[0026] Figure label:

[0027] 1 Transmission line, 10 Antenna terminal, 12 RF source terminal, 14 First transmission line, 16 Second transmission line, 18 Third transmission line, 2 Voltage coupling detection probe, 20 First probe, 22 Second probe, 24 Third probe, 3 Voltage sampling circuit, 30 Voltage conversion module, 300 RF Schottky diode, 32 Voltage detection module, 4 Processing unit, 5 Substrate, 50 Grounding hole, 52 Grounding circuit, 6 Matching circuit, 7 Power management integrated module, 70 Analog-to-digital converter, 8 Test socket, 9 Electronic equipment. Detailed Implementation

[0028] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0029] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "a plurality of" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects.

[0030] In the description of this application, it should be understood that the terms "center", "upper", "lower", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0031] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] The following is combined Figures 1-15 Description of impedance detection circuit and electronic device 9 according to embodiments of this application.

[0033] like Figure 1 , Figure 11 and Figure 12 As shown, an impedance detection circuit according to some embodiments of this application includes: a transmission line 1, including an antenna end 10 and an RF source end 12; at least three voltage coupling detection probes 2, arranged sequentially along the extension direction of the transmission line 1, for coupling and acquiring the RF signal transmitted by the transmission line 1; a voltage sampling circuit 3, connected to the voltage coupling detection probes 2, for acquiring the RF signal acquired by the voltage coupling detection probes 2 and converting it into corresponding DC voltage information; and a processing unit 4, connected to the voltage sampling circuit 3, for receiving the DC voltage information and determining the complex impedance of the transmission line 1 based on the DC voltage information.

[0034] In the embodiments of this application, the impedance detection circuit includes a transmission line 1, at least three voltage coupling detection probes 2, a voltage sampling circuit 3, and a processing unit 4. The transmission line 1 includes an antenna end 10 and a radio frequency source end 12 for carrying radio frequency signal transmission. The at least three voltage coupling detection probes 2 are arranged non-contactly at different positions along the extension direction of the transmission line 1. These voltage coupling detection probes 2 collect the radio frequency signals transmitted by the transmission line 1. The voltage sampling circuit 3 is electrically connected to all voltage coupling detection probes 2, acquires the radio frequency signal collected by each voltage coupling detection probe 2, and converts the radio frequency signal into corresponding DC voltage information. The processing unit 4 receives the DC voltage information output by the voltage sampling circuit 3. Based on the DC voltage information at multiple positions, the complex impedance value on the transmission line 1 can be effectively and accurately detected. In the embodiments proposed in this application, by setting voltage coupling detection probes 2, reliable detection of complex impedance is achieved, which helps to reduce costs, has a fast response time, high detection accuracy, and minimal impact on the transmission line 1.

[0035] In some embodiments of this application, the antenna end 10 of the transmission line 1 is connected to a radio frequency antenna, and the radio frequency source end 12 of the transmission line 1 is connected to a radio frequency transceiver.

[0036] It is understood that in the embodiments proposed in this application, spatial sampling by at least three voltage coupling detection probes 2 improves the measurement accuracy, which is applicable to scenarios such as antenna impedance matching and radio frequency circuit debugging. Based on multi-point voltage data, the complex impedance value can be inverted, which can reduce single-point measurement error and improve reliability.

[0037] Understandably, in related technologies, if an abnormal mismatch occurs, the signal will... Figure 1 The arrow in the image indicates the direction of reflection from antenna end 10 to radio frequency source end 12.

[0038] According to some embodiments of this application, the voltage coupling detection probe 2 may optionally be a microstrip line structure.

[0039] In this embodiment, the voltage coupling detection probe 2 is a microstrip line structure, which allows the voltage coupling detection probe 2 to be implemented on the same printed circuit board process as the transmission line 1, which is also usually a microstrip line, facilitating processing and integration.

[0040] According to some embodiments of this application, optionally, the length direction of the voltage coupling detection probe 2 is arranged parallel to the extension direction of the transmission line 1.

[0041] In this embodiment, the length direction of the voltage coupling detection probe 2 is set parallel to the extension direction of the transmission line 1. This parallel arrangement ensures the directionality and consistency of the electric field coupling.

[0042] According to some embodiments of this application, optionally, a gap is provided between the voltage coupling detection probe 2 and the transmission line 1 to form a coupling capacitor.

[0043] In this embodiment, there is a gap between the voltage coupling detection probe 2 and the transmission line 1, thereby forming a coupling capacitor. The radio frequency signal is coupled to the voltage coupling detection probe 2 through the coupling capacitor. This weak coupling design makes the insertion loss of the detection circuit to the main signal path extremely low.

[0044] Optionally, to ensure that the transmission of the main radio frequency signal on transmission line 1 is as unaffected as possible by the voltage coupling detection probe 2, the isolation between the voltage coupling detection probe 2 and transmission line 1 is set to about 40dB, thereby reducing the load effect and interference on the main channel to an extremely low level.

[0045] Optionally, the isolation between the voltage coupling detection probe 2 and the transmission line 1 is set to less than or equal to 40 dB.

[0046] According to some embodiments of this application, optionally, the radio frequency signal transmitted by the transmission line 1 includes at least one of a first frequency band signal, a second frequency band signal, and a third frequency band signal, wherein the frequency of the first frequency band signal is less than the frequency of the second frequency band signal, and the frequency of the second frequency band signal is less than the frequency of the third frequency band signal; when the radio frequency signal includes the first frequency band signal, the voltage coupling detection probe 2 includes a first probe 20, the width w1 of the first probe 20 is less than or equal to 0.4 mm, and the length h1 of the first probe 20 is less than or equal to 1.3 mm; when the radio frequency signal includes the second frequency band signal, the voltage coupling detection probe 2 includes a second probe 22, the width w1 of the second probe 22 is less than or equal to 0.4 mm, and the length h1 of the second probe 22 is less than or equal to 1.0 mm; when the radio frequency signal includes the third frequency band signal, the voltage coupling detection probe 2 includes a third probe 24, the width w1 of the third probe 24 is less than or equal to 0.4 mm, and the length h1 of the third probe 24 is less than or equal to 0.7 mm.

[0047] In this embodiment, the radio frequency signal transmitted by transmission line 1 includes at least one of a first frequency band signal, a second frequency band signal, and a third frequency band signal, wherein the first frequency band signal has the lowest frequency, the second frequency band signal is next, and the third frequency band signal has the highest frequency: for example... Figure 2 , Figure 3 and Figure 4 As shown, when the radio frequency signal contains the lowest frequency first band signal, the voltage coupling detection probe 2 includes a first probe 20, the width w1 of the first probe 20 being designed to be less than or equal to 0.4 mm, and its length h1 being less than or equal to 1.3 mm; as Figure 5 , Figure 6 and Figure 7As shown, when the radio frequency signal includes a second frequency band signal, the voltage coupling detection probe 2 includes a second probe 22. The width w1 of the second probe 22 is also less than or equal to 0.4 mm, but its length h1 is shortened to less than or equal to 1.0 mm; Figure 8 , Figure 9 and Figure 10 As shown, when the radio frequency signal contains the highest frequency third band signal, the voltage coupling detection probe 2 includes a third probe 24. The width w1 of the third probe 24 is kept less than or equal to 0.4 mm, and the length h1 is less than or equal to 0.7 mm, so that the electrical length h1 of the voltage coupling detection probe 2 matches the working wavelength, maintains sufficient coupling efficiency, and avoids interference with the main signal.

[0048] Optionally, the frequency of the first frequency band signal is 600MHz~1000MHz, the frequency of the second frequency band signal is 1710MHz~2690MHz, and the frequency of the third frequency band signal is 3200MHz~5850MHz.

[0049] It is understood that when the radio frequency signal transmitted by the transmission line 1 includes a first frequency band signal, a second frequency band signal and a third frequency band signal, any voltage coupling detection probe 2 includes at least a first probe 20, a second probe 22 and a third probe 24.

[0050] According to some embodiments of this application, optionally, the width w1 and length h1 of the first probe 20 are matched with the first frequency band signal, the width w1 and length h1 of the second probe 22 are matched with the second frequency band signal, and the width w1 and length h1 of the third probe 24 are matched with the third frequency band signal; wherein, when the radio frequency signal transmitted by the transmission line 1 is the first frequency band signal, the voltage sampling circuit 3 is connected to the first probe 20; when the radio frequency signal transmitted by the transmission line 1 is the second frequency band signal, the voltage sampling circuit 3 is connected to the second probe 22; and when the radio frequency signal transmitted by the transmission line 1 is the third frequency band signal, the voltage sampling circuit 3 is connected to the third probe 24.

[0051] In this embodiment, the width w1 and length h1 of the first probe 20 are matched with the first frequency band signal, the dimensions of the second probe 22 are matched with the second frequency band signal, and the dimensions of the third probe 24 are matched with the third frequency band signal. That is, each sub-probe is optimized for its corresponding frequency band to achieve efficient signal coupling and avoid self-resonance in each target frequency band. At the same time, when the transmission line 1 outputs different frequencies, the voltage sampling circuit 3 can switch to use different probes according to different frequencies. In some embodiments of this application, the impedance detection circuit includes a switching circuit. When the radio frequency signal transmitted by the transmission line 1 is a first frequency band signal, the voltage sampling circuit 3 is connected to the first probe 20 through the switching circuit to detect the radio frequency signal transmitted by the transmission line 1; when the radio frequency signal transmitted by the transmission line 1 is a second frequency band signal, the voltage sampling circuit 3 is connected to the second probe 22 through the switching circuit to detect the radio frequency signal transmitted by the transmission line 1; when the radio frequency signal transmitted by the transmission line 1 is a third frequency band signal, the voltage sampling circuit 3 is connected to the third probe 24 through the switching circuit to detect the radio frequency signal transmitted by the transmission line 1. Understandably, the switching circuit can be a single-pole multi-throw switch, with its fixed end connected to the voltage sampling circuit 3, and its movable segments connected to the first probe 20, the second probe 22, and the third probe 24 respectively. Depending on the frequency band of the radio frequency signal transmitted through the transmission line 1, different probes can be connected and coupled through the switching circuit to acquire the radio frequency signal. For example, when transmitting a signal in the first frequency band, the first probe is connected; when transmitting a signal in the second frequency band, the second probe is connected; and when transmitting a signal in the third frequency band, the third probe is connected.

[0052] It is understood that the length h1 and width w1 of the first probe 20 are matched with the first frequency band signal, that is, the width w1 of the first probe 20 is less than or equal to 0.4 mm and the length h1 of the first probe 20 is less than or equal to 1.3 mm; the length h1 and width w1 of the second probe 22 are matched with the second frequency band signal, that is, the width w1 of the second probe 22 is less than or equal to 0.4 mm and the length h1 of the first probe 20 is less than or equal to 1 mm; the length h1 and width w1 of the third probe 24 are matched with the third frequency band signal, that is, the width w1 of the third probe 24 is less than or equal to 0.4 mm and the length h1 of the third probe 24 is less than or equal to 0.7 mm.

[0053] According to some embodiments of this application, optionally, the distance between the voltage coupling detection probe 2 and the transmission line 1 is greater than the line width of the transmission line 1.

[0054] In this embodiment, the distance between the voltage coupling detection probe 2 and the transmission line 1 is greater than the linewidth of the transmission line 1 itself, ensuring that the coupling area has sufficient spatial span, which is conducive to forming a more stable coupling capacitor with appropriate capacitance value. At the same time, it can effectively reduce parasitic electromagnetic field interference caused by the conductors being too close together, thereby making the signal coupling coefficient from the transmission line 1 to the voltage coupling detection probe 2 more controllable.

[0055] According to some embodiments of this application, optionally, the distance between two adjacent voltage coupling detection probes 2 is less than or equal to λ / 20, where λ is the wavelength of the radio frequency signal transmitted by the transmission line 1.

[0056] In this embodiment, the distance between two adjacent voltage coupling detection probes 2 is less than or equal to λ / 20, so as to reduce the space occupied by the voltage coupling detection probes 2 and thus adapt to the miniaturization design of the electronic device 9.

[0057] According to some embodiments of this application, optionally, such as Figure 11 As shown, at least three voltage coupling detection probes 2 are located on the same side of transmission line 1, or as... Figure 12 As shown, at least three voltage coupling detection probes 2 are located on opposite sides of the transmission line 1.

[0058] In this embodiment, at least three voltage coupling detection probes 2 are located on the same side of the transmission line 1, which simplifies the wiring and only requires a space for installation and shielding on one side of the substrate 5, which helps to simplify the design and save layout area; or, at least three voltage coupling detection probes 2 are located on opposite sides of the transmission line 1, which can make fuller use of the space on both sides of the transmission line 1 and help to arrange multiple voltage coupling detection probes 2 in a compact space.

[0059] like Figure 11 and Figure 12 As shown, according to some embodiments of this application, optionally, at least three voltage coupling detection probes 2 are located near the antenna end 10, the radio frequency source end 12, and the position between the antenna end 10 and the radio frequency source end 12, respectively.

[0060] In this embodiment, at least three voltage coupling detection probes 2 are respectively arranged near the antenna end 10, near the RF source end 12, and between the antenna end 10 and the RF source end 12. At least one voltage coupling detection probe 2 is positioned in the transmission line 1 region immediately adjacent to the antenna connection point to couple and acquire the RF signal closest to the antenna load. At least one voltage coupling detection probe 2 is positioned in the transmission line 1 region immediately adjacent to the RF source connection point to acquire the RF signal closest to the signal source. At least one voltage coupling detection probe 2 positioned between the antenna end 10 and the RF source end 12 synchronously acquires voltage data, thereby more accurately retrieving the complex impedance of the load.

[0061] Understandably, if only two voltage-coupled detection probes 2 are used, the equations that can be established may not be sufficient to solve all unknown parameters with high accuracy. The three-point arrangement provides data redundancy, which helps to reduce errors and enhances the measurement reliability of the entire impedance detection circuit.

[0062] According to some embodiments of this application, optionally, the impedance detection circuit further includes: a test socket 8 and a matching circuit 6; the transmission line 1 includes a first transmission line 14, a second transmission line 16, and a third transmission line 18; one end of the first transmission line 14 includes an antenna end 10, and one end of the third transmission line 18 includes an RF source end 12; the other end of the first transmission line 14 is connected to the test socket 8; both ends of the second transmission line 16 are respectively connected to the test socket 8 and the matching circuit 6; the other end of the third transmission line 18 is connected to the matching circuit 6; at least one voltage coupling detection probe 2 is disposed opposite to the first transmission line 14, at least one voltage coupling detection probe 2 is disposed opposite to the second transmission line 16, and at least one voltage coupling detection probe 2 is disposed opposite to the third transmission line 18; wherein, the matching circuit 6 is connected to the processing unit 4, the processing unit 4 determines the matching parameters according to the complex impedance, and transmits the matching parameters to the matching circuit 6, the matching circuit 6 is used to adjust the impedance of the matching circuit 6 according to the matching parameters.

[0063] In this embodiment, the impedance detection circuit further includes a test socket 8 and a matching circuit 6. Meanwhile, the transmission line 1 includes a first transmission line 14, a second transmission line 16, and a third transmission line 18. One end of the first transmission line 14 is an antenna terminal 10 for connecting the antenna under test to the load, and the other end is connected to the test socket 8. The second transmission line 16 serves as an intermediate bridge, with its two ends connected to the test socket 8 and the matching circuit 6, respectively. One end of the third transmission line 18 is an RF source terminal 12 for connecting to an RF signal source, and the other end is connected to the matching circuit 6, allowing the antenna under test to be easily connected or disconnected via the test socket 8. The entire detection system is activated. During detection, at least one voltage coupling detection probe 2 is arranged along each transmission line. Specifically, at least one voltage coupling detection probe 2 is positioned opposite to the first transmission line 14 to collect the voltage near the antenna end 10; at least one voltage coupling detection probe 2 is positioned opposite to the second transmission line 16 to collect the voltage of the intermediate connection section; and at least one voltage coupling detection probe 2 is positioned opposite to the third transmission line 18 to collect the voltage near the RF source end 12. The signals collected by all voltage coupling detection probes 2 are sent to the voltage sampling circuit and processing unit 4 to calculate the complex impedance. In addition, the matching circuit 6 is connected to the processing unit 4. The processing unit 4 no longer simply outputs the complex impedance information, but determines the matching parameters to match the impedance to the target point based on the complex impedance, thereby achieving the tuning of the impedance of the matching circuit 6.

[0064] Optionally, the matching circuit 6 is used to adjust the impedance of the matching circuit 6 according to the matching parameters. This can be achieved by the matching circuit 6 determining the adjustment parameters based on the matching parameters and issuing a reminder message to remind the user to adjust the impedance of the matching circuit 6 according to the prompt message; or by the matching circuit 6 determining the adjustment parameters based on the matching parameters and sending the adjustment parameters to the automatic tuning module, so that the automatic tuning module can adjust the impedance of the matching circuit 6 itself.

[0065] Optionally, the electronic device includes an automatic tuning module.

[0066] Understandably, test socket 8 is used to install test modules.

[0067] It is understood that impedance matching as referred to in this application means matching the impedance of the radio frequency antenna with the impedance of the transmission line; in some embodiments of this application, impedance matching of the radio frequency antenna with the transmission line specifically means that the impedance magnitude and phase are the same. The radio frequency antenna impedance can be either the input impedance or the output impedance of the radio frequency antenna.

[0068] According to some embodiments of this application, optionally, the processing unit 4 determines the tuning path of the matching circuit 6 and the corresponding component adjustment amount on the Smith chart based on the complex impedance.

[0069] In this embodiment, by enabling the processing unit 4 to perform visual analysis and path planning on the Smith chart based on the calculated complex impedance, the tuning path and component adjustment amount of the current mismatch state can be determined, and control commands can be generated accordingly to drive the matching circuit 6 to perform the adjustment. This realizes the overall control from impedance detection to tuning execution, avoiding the inefficiency and uncertainty of blind traversal or trial and error adjustment in related technologies, thereby improving the accuracy, speed and reliability of impedance matching.

[0070] like Figure 15 As shown, according to some embodiments of this application, optionally, the voltage sampling circuit 3 includes: a voltage conversion module 30 connected to the voltage coupling detection probe 2, used to convert the radio frequency signal into a DC voltage signal; and a voltage detection module 32 connected to the voltage conversion module 30, used to convert the DC voltage signal into DC voltage information.

[0071] In this embodiment, the voltage sampling circuit 3 includes a voltage conversion module 30 and a voltage detection module 32. The input terminal of the voltage conversion module 30 is connected to the output terminal of the voltage coupling detection probe 2, and converts the radio frequency signal (i.e., the high-frequency AC voltage signal) coupled and collected from the transmission line 1 into a corresponding DC voltage signal to extract the amplitude information of the radio frequency signal. The input terminal of the voltage detection module 32 is connected to the output terminal of the voltage conversion module 30, and further converts the DC voltage signal representing the amplitude into DC voltage information that is easy for digital systems to process. The embodiment proposed in this application achieves stable and efficient digital conversion of radio frequency signals through the hierarchical processing of the voltage conversion module 30 and the voltage detection module 32. The circuit structure is simple and reliable, reducing system complexity and cost.

[0072] like Figure 13 and Figure 15 As shown, according to some embodiments of this application, optionally, the voltage conversion module 30 includes an RF Schottky diode 300, and the voltage coupling detection probe 2 is connected to the RF Schottky diode 300.

[0073] In this embodiment, the voltage conversion module 30 includes an RF Schottky diode 300. The output terminal of the voltage coupling detection probe 2 is directly connected to the input terminal of the RF Schottky diode 300 to convert the RF AC voltage signal transmitted from the voltage coupling detection probe 2 into a DC voltage signal. The RF Schottky diode 300, due to its extremely low junction capacitance and extremely fast reverse recovery time, can quickly respond to changes in the RF voltage, thereby minimizing signal distortion and loss during rectification. Furthermore, by adding the RF Schottky diode 300, the conversion from RF signal to DC voltage is achieved, thereby reducing manufacturing costs and the size occupied.

[0074] like Figure 11 and Figure 12 As shown, according to some embodiments of this application, optionally, the voltage coupling detection probe 2 and the transmission line 1 are disposed on the substrate 5, and the substrate 5 is provided with a plurality of grounding holes 50, which surround at least a portion of the periphery of the voltage coupling detection probe 2.

[0075] In this embodiment, the voltage coupling detection probe 2 and the transmission line 1 are disposed on the substrate 5. The substrate 5 is provided with a plurality of grounding holes 50. These grounding holes 50 surround at least part of the periphery of the voltage coupling detection probe 2, which can prevent the voltage coupling detection probe 2 from interfering with the signal by secondary coupling, prevent signal leakage, and also prevent interference from other signals, thereby indirectly improving the accuracy and stability of the subsequent processing unit 4 in calculating the complex impedance.

[0076] Optionally, the substrate 5 includes a grounding circuit 52, and a grounding hole 50 is disposed in the grounding circuit 52.

[0077] According to some embodiments of this application, the voltage coupling detection probe 2 may optionally be disposed in the inner layer or the surface layer of the substrate 5.

[0078] In this embodiment, the voltage coupling detection probe 2 can be disposed in the inner layer or the surface layer of the substrate 5. When the voltage coupling detection probe 2 is disposed in the surface layer of the substrate 5, the voltage coupling detection probe 2 is exposed in the outermost layer of the substrate 5, which is simple to process and easy to directly detect or debug. When the voltage coupling detection probe 2 is disposed in the inner layer of the substrate 5, the voltage coupling detection probe 2 is embedded between the intermediate dielectric layers of the substrate 5. This arrangement can provide it with natural physical protection, prevent scratches or contamination, and can more effectively utilize the grounding layers of the upper and lower layers for shielding, which helps to further reduce electromagnetic interference with the external environment or other lines.

[0079] According to some embodiments of this application, optionally, the processing unit 4 calculates the magnitude and phase of the reflection coefficient of the transmission line 1 based on the DC voltage information of at least three voltage coupling detection probes 2, and determines the complex impedance based on the magnitude and phase.

[0080] In this embodiment, the processing unit 4 calculates the reflection coefficient on the transmission line 1 based on at least three sets of received DC voltage information, and then solves for the complex impedance. Specifically, the processing unit 4 calculates the magnitude and phase of the reflection coefficient based on the RF voltage amplitude information corresponding to the DC voltage information at multiple locations, combined with the known position parameters of the voltage coupling detection probe 2 and the transmission line 1 model, by solving the transmission line 1 equation or performing parameter fitting. Subsequently, the processing unit 4 calculates the corresponding complex impedance value using the obtained magnitude and phase of the reflection coefficient according to the standard impedance transformation formula, providing crucial and reliable load information for applications such as antenna matching circuit adjustment and RF power control.

[0081] Optionally, the scalar information of voltage amplitude collected from multiple points in space is reconstructed into the complex information of reflection coefficient, which includes amplitude and phase, through the theoretical model of transmission line 1, and finally mapped to the complex impedance of the load.

[0082] Optionally, the workflow of the complex impedance detection section is as follows:

[0083] (1) The DC voltage scalar values ​​U1, U2, and U3 of the three voltage-coupled detection probes 2 are detected by the circuit described above and synchronously sampled. Under small signal input (usually less than -20dBm), the RF Schottky diode 300 operates in the square-law region. Its output DC voltages U1, U2, and U3 are proportional to the square of the input RF voltage amplitude V(z), that is:

[0084] (1)

[0085] (2) The phase of the voltage acquired by the voltage coupling detection probe 2 is calculated using the three-point standing wave reconstruction method. The principle is as follows:

[0086] The voltage V(z) at a distance z from the load on transmission line 1 is the superposition of the incident wave and the reflected wave.

[0087] ; (2)

[0088] Where V + It is the amplitude of the incident wave. φ is the complex reflection coefficient, φ is the phase (phase angle) of the reflection coefficient; j is the imaginary unit used to represent the phase part of the complex number, β=2π / λ is the phase constant, and λ represents the wavelength.

[0089] The square of the voltage amplitude detected by voltage coupling detection probe 2 for:

[0090] (3)

[0091] We measured three voltage values, U1, U2, and U3, at three known locations z1, z2, and z3. This constitutes a problem involving three unknowns (...). The nonlinear equations of the above (hence the need to place three probes at different positions).

[0092] (4)

[0093] in, It is a known electrical length, and K is a proportionality constant that includes incident power and circuit gain; this is an intermediate quantity.

[0094] The solution can be obtained by expanding the cosine terms using trigonometric identities, resulting in:

[0095] (5)

[0096] in:

[0097] (6)

[0098] (7)

[0099] (8)

[0100] In the CPU, the above equations can be solved simply by matrix inversion, ultimately yielding the values ​​of A, B, and C. Once A, B, and C are obtained, the magnitude and phase of the reflection coefficient can be solved in reverse, as shown below:

[0101] (1) Calculate the phase:

[0102] (9)

[0103] (2) Calculate the modulus:

[0104] Using relational expressions: and Eliminating K yields a result about Solving the quadratic equation yields the modulus. , .

[0105] (3) The final complex load impedance at each location can be calculated as follows:

[0106] Z0 = 50Ω; (10)

[0107] For Z L By performing a virtual-real expansion, the resistance R can be obtained. L and reactance X L .

[0108] The above calculation process yields the radio frequency parameters at different positions of z1, z2, and z3.

[0109] The final result is:

[0110] The magnitude of the reflection coefficient is used to determine the degree of mismatch;

[0111] Φ: Reflection coefficient phase, used to describe the nature of the mismatch and determine whether it is an inductive mismatch or a capacitive mismatch;

[0112] Z L Complex impedance is used to guide the debugging of matching circuits.

[0113] Using the above methods, the magnitude and nature of the mismatch (inductive or capacitive) can be obtained. The complex impedance obtained from the solution can be plotted on the Smith chart, thereby guiding the deterministic tuning of the matching circuit and avoiding the waste of time by repeated searching and debugging.

[0114] This application provides an electronic device 9, which includes an impedance detection circuit as described in any of the above claims, and thus has all the beneficial effects of an impedance detection circuit, which will not be repeated here.

[0115] like Figure 14 As shown, according to some embodiments of this application, optionally, the electronic device 9 further includes: a power management integrated module 7, which includes an analog-to-digital converter 70; in the case where the voltage sampling circuit 3 of the impedance detection circuit includes a voltage detection module 32, the voltage detection module 32 is the analog-to-digital converter 70.

[0116] In this embodiment, when the voltage sampling circuit 3 of the impedance detection circuit includes a voltage detection module 32, the voltage detection module 32 is an analog-to-digital converter 70. That is, the voltage detection module 32 directly reuses the analog-to-digital converter 70 in the power management integrated module 7 already in the electronic device 9, realizing a high degree of integration and reuse of hardware resources, saving the layout area and material cost required by independent dedicated analog-to-digital converter chips, and reducing system complexity and overall power consumption.

[0117] Optionally, according to some embodiments of this application, this application proposes a mobile phone board-level RF antenna mismatch detection and improvement circuit. This circuit can more quickly and accurately calculate the magnitude and nature of the mismatch between the RF and the antenna, and guide rapid tuning, thereby improving detection efficiency. Wherein:

[0118] (1) By placing three voltage coupling detection probes 2 at different positions close to the transmission line 1, the complex impedance can be detected effectively and accurately. At the same time, the voltage coupling detection probes 2 are in the form of microstrip lines. By adjusting the shape and the gap with the main path, the isolation between them and the signal of the transmission line 1 can be controlled, which is different from the traditional directional coupler.

[0119] (2) It is very small in size. Compared with traditional methods, the discrete device is only a diode (e.g., RF Schottky diode 300), without the need to add additional devices, and the cost is low.

[0120] (3) The response time is very fast, the detection of mismatch is accurate, and the matching and tuning can be performed quickly.

[0121] (4) It has almost no effect on the transmission of signals on transmission line 1.

[0122] The embodiments proposed in this application include an impedance detection circuit and an impedance mismatch automatic tuning module.

[0123] I. The impedance detection circuit consists of the following parts:

[0124] 1. Main transmission line 1 (e.g., transmission line 1). Transmission line 1 is usually the RF common terminal trace. Mismatch scenarios often occur in this section of the line. After an abnormal mismatch occurs, the signal is reflected from the antenna end 10 to the RF source end 12.

[0125] 2. Voltage coupling detection probe 2 consists of three tiny rectangular copper foils (P1, P2, P3). These three micro-probes are placed parallel to transmission line 1, with an isolation of approximately 40 dB between the probes and transmission line 1. The maximum transmit power of the PC3 standard specified by the IEEE (Institute of Electrical and Electronics Engineers) communication protocol is 23 dBm, and the maximum transmit power of the PC2 standard is 26 dBm. In the case of mismatch, the higher the power, the greater the impact; therefore, it is sufficient to detect a power range of 0 dBm to 26 dBm. Thus, the voltage coupling detection probe 2 can detect a power of approximately -40 dBm to -14 dBm, which is within the linear power detection range of the RF Schottky diode 300.

[0126] The specific structure and placement of the voltage coupling detection probe 2 should follow these rules:

[0127] a. A gap exists between the probe and transmission line 1, forming a very small coupling capacitance. This weak coupling design ensures that the insertion loss of the detection circuit to the main signal path is extremely low (<0.1dB).

[0128] b. Spacing of Voltage Coupling Detection Probes 2: To obtain voltage samples containing phase information, a certain physical spacing is required between the voltage coupling detection probes 2. To meet the miniaturization requirements of mobile phones, this solution adopts a reduced spacing design, such as λ / 20 or smaller. Of course, they can be freely placed according to the PCB (Printed Circuit Board) space, but the spacing needs to be recorded. Since it is to detect the mismatch between the antenna and the radio frequency, the best placement for the three voltage coupling detection probes 2 is one behind the antenna mount, one at the RF common source terminal, and one in the middle of the trace.

[0129] c. Isolation network: To prevent the voltage coupling detection probe 2 from causing interference due to secondary coupling of the signal, a ring of grounding holes 50 needs to be added around the voltage coupling detection probe 2 to prevent signal leakage and interference from other signals.

[0130] Depending on the actual detection frequency band, multiple implementations can be formed here. The low frequency is specified as 600MHz~1000MHz (typical frequency bands B5, B8, etc.), the mid-high frequency is 1710MHz~2690MHz (typical frequency bands B1, B41, etc.), and the ultra-high frequency is 3200MHz~5850MHz (typical frequency bands n78, Wifi 5GHz). In order to achieve the optimal frequency detection range, multiple sizes can be optimized.

[0131] After simulation optimization, the structural dimensions of a single voltage coupling detection probe 2 are as follows: Figure 2 , Figure 5 or Figure 8 As shown:

[0132] (1) Low frequency (e.g., the frequency corresponding to the first frequency band signal): Key dimensions of the passive structure of the low frequency probe are as follows Figure 2 As shown, the dimensions of each position (e.g., h3, h4, h5, w2) can be designed according to the corresponding frequency and different PCB stack-ups. Among them, the width w1 of the voltage coupling detection probe 2 is no more than 0.4mm and the length h1 of the voltage coupling detection probe 2 is no more than 1.3mm. The dimensions are optimized through simulation.

[0133] like Figure 3 As shown, the spacing S1 between the adjusted transmission line 1 path and the voltage coupling detection probe 2 needs to be greater than 1 times the line width w. line To ensure engineering capabilities.

[0134] The isolation between the probe and transmission line 1 is as follows: Figure 4 As shown, it conforms to the preset value, where m1 and m2 represent the markers of the measured values.

[0135] (2) Mid-to-high frequency (e.g., the frequency corresponding to the second frequency band signal): Key dimensions of the passive structure of the mid-to-high frequency probe are as follows Figure 5 As shown, the dimensions of each position (e.g., h2, h3, w2) can be designed according to the corresponding frequency and different PCB stack-ups. Among them, the width w1 of the voltage coupling detection probe 2 does not exceed 0.4mm, and the length h1 of the voltage coupling detection probe 2 does not exceed 1mm. The dimensions are tuned to the optimal value through simulation.

[0136] like Figure 6 As shown, the spacing S1 between the adjusted transmission line 1 path and the voltage coupling detection probe 2 needs to be greater than 1 times the line width w. line To ensure engineering capabilities.

[0137] The isolation between the probe and transmission line 1 is as follows: Figure 7 As shown, it conforms to the preset value, where m1 and m2 represent the markers of the measured values.

[0138] (3) Ultra-high frequency (e.g., the frequency corresponding to the third frequency band signal): key dimensions such as Figure 8 As shown, the dimensions marked at each position (e.g., h2, h3, w2) can be designed according to the corresponding frequency and different PCB stack-ups. Among them, the width w1 of the voltage coupling detection probe 2 does not exceed 0.4mm, and the length h1 of the voltage coupling detection probe 2 does not exceed 0.7mm. The dimensions are tuned to the optimal value through simulation.

[0139] like Figure 9As shown, the spacing S1 between the adjusted transmission line 1 path and the voltage coupling detection probe 2 needs to be greater than 1 times the line width w. line To ensure engineering capabilities.

[0140] The isolation between the probe and transmission line 1 is as follows: Figure 10 As shown, it conforms to the preset value, where m3 and m4 represent the markers of the measured values.

[0141] based on Figure 1 For the common terminal of the example, at least three voltage coupling detection probes 2 should be placed. The placement positions need to be recorded according to the actual wavelength, specifically z1, z2, and z3. A simplified placement diagram is shown below. Figure 11 and Figure 12 As shown, the voltage coupling detection probe 2 is placed on one side of the transmission line 1. Depending on the actual situation, the voltage coupling detection probe 2 can be placed on both sides of the transmission line 1, as long as S1 remains unchanged. At the same time, grounding holes 50 are drilled around the voltage coupling detection probe 2 for protection.

[0142] 3. AC / DC Conversion and Voltage Detection Module 32. A trace is led from the voltage coupling detection probe 2 to the RF Schottky diode 300 (surface mount package, 0201 size, inexpensive) to convert the RF signal into DC voltage. To reduce cost, the voltage detection module 32 can use the PMIC (Power Management Integrated Circuit) inside the mobile phone. Typically, the PMIC has multiple spare AUXADC (auxiliary voltage detection) pins that can be connected to perform voltage detection.

[0143] Therefore, it can be seen that the circuit built in this application only requires the addition of the RF Schottky diode 300, and the corresponding functions can be achieved by using microstrip lines or multiplexed mobile phone ICs (integrated circuits).

[0144] Optionally, the workflow of the complex impedance detection section is as follows:

[0145] (1) The DC voltage scalar values ​​U1, U2, and U3 of the three voltage-coupled detection probes 2 are detected by the circuit described above and synchronously sampled. Under small signal input (usually less than -20dBm), the RF Schottky diode 300 operates in the square-law region. Its output DC voltages U1, U2, and U3 are proportional to the square of the input RF voltage amplitude V(z), that is:

[0146] ; (1)

[0147] (2) The phase of the voltage acquired by the voltage coupling detection probe 2 is calculated using the three-point standing wave reconstruction method. The principle is as follows:

[0148] The voltage V(z) at a distance z from the load on transmission line 1 is the superposition of the incident wave and the reflected wave.

[0149] ; (2)

[0150] Where V + It is the amplitude of the incident wave. φ is the complex reflection coefficient, φ is the phase (phase angle) of the reflection coefficient; j is the imaginary unit used to represent the phase part of the complex number, β=2π / λ is the phase constant, and λ represents the wavelength.

[0151] The square of the voltage amplitude detected by voltage coupling detection probe 2 for:

[0152] ; (3)

[0153] We measured three voltage values, U1, U2, and U3, at three known locations z1, z2, and z3. This constitutes a problem involving three unknowns (...). The nonlinear equations of the above (hence the need to place three probes at different positions).

[0154] ; (4)

[0155] in, It is a known electrical length, and K is a proportionality constant that includes incident power and circuit gain; this is an intermediate quantity.

[0156] The solution can be obtained by expanding the cosine terms using trigonometric identities, resulting in:

[0157] ; (5)

[0158] in:

[0159] ; (6)

[0160] ; (7)

[0161] ; (8)

[0162] In the CPU, the above equations can be solved simply by matrix inversion, ultimately yielding the values ​​of A, B, and C. Once A, B, and C are obtained, the magnitude and phase of the reflection coefficient can be solved in reverse, as shown below:

[0163] (1) Calculate the phase:

[0164] ; (9)

[0165] (2) Calculate the modulus:

[0166] Using relational expressions: and Eliminating K yields a result about Solving the quadratic equation yields the modulus. , .

[0167] (3) The final complex load impedance at each location can be calculated as follows:

[0168] Z0 = 50Ω; (10)

[0169] For Z L By performing a virtual-real expansion, the resistance R can be obtained. L and reactance X L .

[0170] The above calculation process yields the radio frequency parameters at different positions of z1, z2, and z3.

[0171] The final result is:

[0172] The magnitude of the reflection coefficient is used to determine the degree of mismatch;

[0173] Φ: Reflection coefficient phase, used to describe the nature of the mismatch and determine whether it is an inductive mismatch or a capacitive mismatch;

[0174] Z L Complex impedance is used to guide the debugging of matching circuits.

[0175] Using the above methods, the magnitude and nature of the mismatch (inductive or capacitive) can be obtained. The complex impedance obtained from the solution can be plotted on the Smith chart, thereby guiding the deterministic tuning of the matching circuit and avoiding the waste of time by repeated searching and debugging.

[0176] Alternatively, passive probes can be placed on the inner layers of the circuit board, which can save more surface space. However, placing them on the inner layers may cause impedance discontinuities in the transmission lines and increase insertion loss, requiring performance optimization through structural and dimensional adjustments. Alternatively, a miniaturized tunable network can be introduced to achieve closed-loop adjustment.

[0177] Alternatively, in addition to detecting mismatches, miniaturized passive devices can be extended to other fields, such as designing miniaturized PCB filters, combiners, and notch filters.

[0178] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0179] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. An impedance detection circuit, characterized in that, include: Transmission line, including antenna end and radio frequency source end; At least three voltage-coupled detection probes are arranged sequentially along the extension direction of the transmission line for coupling and acquiring the radio frequency signal transmitted by the transmission line; A voltage sampling circuit, connected to the voltage coupling detection probe, is used to acquire the radio frequency signal collected by the voltage coupling detection probe and convert it into corresponding DC voltage information; The processing unit is connected to the voltage sampling circuit and is used to receive the DC voltage information and determine the complex impedance of the transmission line based on the DC voltage information.

2. The impedance detection circuit according to claim 1, characterized in that, The length direction of the voltage coupling detection probe is parallel to the extension direction of the transmission line.

3. The impedance detection circuit according to claim 1, characterized in that, The voltage coupling detection probe has a gap with the transmission line to form a coupling capacitance.

4. The impedance detection circuit according to claim 1, characterized in that, The radio frequency signal transmitted by the transmission line includes at least one of a first frequency band signal, a second frequency band signal, and a third frequency band signal, wherein the frequency of the first frequency band signal is lower than the frequency of the second frequency band signal, and the frequency of the second frequency band signal is lower than the frequency of the third frequency band signal. When the radio frequency signal includes the first frequency band signal, the voltage coupling detection probe includes a first probe, the width of the first probe is less than or equal to 0.4 mm, and the length of the first probe is less than or equal to 1.3 mm; When the radio frequency signal includes the second frequency band signal, the voltage coupling detection probe includes a second probe, the width of the second probe is less than or equal to 0.4 mm, and the length of the second probe is less than or equal to 1.0 mm; When the radio frequency signal includes the third frequency band signal, the voltage coupling detection probe includes a third probe, the width of the third probe is less than or equal to 0.4 mm, and the length of the third probe is less than or equal to 0.7 mm.

5. The impedance detection circuit according to claim 4, characterized in that, Also includes: Switching circuit; The width and length of the first probe are matched with the first frequency band signal, the width and length of the second probe are matched with the second frequency band signal, and the width and length of the third probe are matched with the third frequency band signal; Wherein, when the radio frequency signal transmitted by the transmission line is the first frequency band signal, the voltage sampling circuit is connected to the first probe through the switching circuit; When the radio frequency signal transmitted through the transmission line is a signal of the second frequency band, the voltage sampling circuit is connected to the second probe through the switching circuit; When the radio frequency signal transmitted through the transmission line is the third frequency band signal, the voltage sampling circuit is connected to the third probe through the switching circuit.

6. The impedance detection circuit according to any one of claims 1 to 5, characterized in that, The distance between the voltage coupling detection probe and the transmission line is greater than the line width of the transmission line.

7. The impedance detection circuit according to any one of claims 1 to 5, characterized in that, The distance between two adjacent voltage coupling detection probes is less than or equal to λ / 20, where λ is the wavelength of the radio frequency signal transmitted by the transmission line.

8. The impedance detection circuit according to any one of claims 1 to 5, characterized in that, At least three of the voltage coupling detection probes are located on the same side of the transmission line, or at least three of the voltage coupling detection probes are located on opposite sides of the transmission line.

9. The impedance detection circuit according to any one of claims 1 to 5, characterized in that, Also includes: The test socket and matching circuit, wherein the transmission line includes a first transmission line, a second transmission line and a third transmission line, one end of the first transmission line includes the antenna end, and one end of the third transmission line includes the radio frequency source end; The other end of the first transmission line is connected to the test socket, the two ends of the second transmission line are respectively connected to the test socket and the matching circuit, and the other end of the third transmission line is connected to the matching circuit. At least one of the voltage coupling detection probes is disposed opposite to the first transmission line, at least one of the voltage coupling detection probes is disposed opposite to the second transmission line, and at least one of the voltage coupling detection probes is disposed opposite to the third transmission line; The matching circuit is connected to the processing unit. The processing unit determines the matching parameters based on the complex impedance and transmits the matching parameters to the matching circuit. The matching circuit is used to adjust the impedance of the matching circuit according to the matching parameters.

10. The impedance detection circuit according to any one of claims 1 to 5, characterized in that, The voltage sampling circuit includes: A voltage conversion module, connected to the voltage coupling detection probe, is used to convert the radio frequency signal into a DC voltage signal; A voltage detection module, connected to the voltage conversion module, is used to convert the DC voltage signal into DC voltage information.

11. The impedance detection circuit according to claim 10, characterized in that, The voltage conversion module includes an RF Schottky diode, and the voltage coupling detection probe is connected to the RF Schottky diode.

12. The impedance detection circuit according to any one of claims 1 to 5, characterized in that, The voltage coupling detection probe and the transmission line are disposed on a substrate, and the substrate is provided with a plurality of grounding holes, which surround at least a portion of the periphery of the voltage coupling detection probe.

13. An electronic device, characterized in that, include: The impedance detection circuit as described in any one of claims 1 to 12.

14. The electronic device according to claim 13, characterized in that, Also includes: A power management integrated module, the power management integrated module including an analog-to-digital converter; The voltage sampling circuit of the impedance detection circuit includes a voltage detection module, which is the analog-to-digital converter.

Images