Method and system for automatically calibrating impedance range of radio frequency matcher

Abstract

The invention discloses an automatic impedance range calibration method for a radio frequency matcher, which comprises the following steps of: driving a variable capacitor of a standard matcher according with a design standard to scan and record impedance data under the connection mode that the input end is connected with a standard load and the output end is connected with a network analyzer and the specific configuration of the network analyzer; establishing a standard impedance range database; performing equivalent impedance scanning on the matcher to be calibrated in the same connection mode, and recording data; comparing the impedance data of the matcher to be calibrated with the standard database to determine an effective working interval of the capacitor; and finally, writing the effective interval as a limit into the control configuration of the matcher to be calibrated, and limiting the capacitance adjustment range of the matcher to be calibrated during normal operation. The automatic calibration system comprises a standard impedance measurement unit, an automatic control and data processing unit and a calibration execution unit. And the whole calibration process is controlled by a program, manual intervention is not needed, and the production efficiency is remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of radio frequency power technology, in particular to an impedance range automatic calibration method and system of a radio frequency matching device. BACKGROUND

[0002] The radio frequency matching device is a key component in the radio frequency system, which functions to transform the complex impedance of the load to the optimal impedance required by the radio frequency source, usually 50 ohms, through adjusting the internal inductance and variable capacitance, so as to achieve the maximum transmission of power and reduce the reflected wave.

[0003] In actual production and manufacturing, due to the manufacturing tolerance and performance error of the core components (such as vacuum variable capacitor and inductor), even if the matching devices of the same model and the same batch, the final impedance matching range will also have differences, that is, the range in which the matching device can successfully match the load to the target impedance. In order to ensure the consistency of the performance of all the matching devices leaving the factory, especially to ensure that the matching range meets the design standard, calibration must be carried out in the production link. At present, the industry generally adopts manual calibration method. The operator needs to connect the matching device to the network analyzer and the load, and then manually adjusts the two variable capacitors repeatedly, observes the impedance point change on the Smith chart, and sets the minimum and maximum physical limit points or software limit values of the capacitors through experience judgment, so that the matching range of the matching device is basically consistent with the standard range. However, at present, this method of manual calibration has the following obvious shortcomings:

[0004] 1) Low efficiency: completely relying on manual operation and judgment, the process is tedious and time-consuming;

[0005] 2) Sparse calibration points: due to the time cost, manual calibration usually only tests a few key points, which cannot fully and accurately depict the boundary of the entire matching range, and may lead to some potential matching points not being covered;

[0006] 3) Poor precision and consistency: the precision of manual calibration is greatly affected by the experience and technical level of the operator, and it is difficult to ensure the high consistency of the performance of different matching devices and different batches of products. SUMMARY

[0007] In view of the deficiencies of the prior art, the present application discloses an impedance range automatic calibration method and system of a radio frequency matching device, which can automatically, accurately and efficiently complete the impedance range automatic calibration of the radio frequency matching device, so as to solve the problems in the background art.

[0008] To achieve the above purpose, the present application provides the following technical scheme: an impedance range automatic calibration method of a radio frequency matching device, comprising the following steps:

[0009] S1, establishing a standard impedance range database;

[0010] S2, automatically impedance scanning on the to-be-calibrated matching device;

[0011] S3, comparing the impedance data of the to-be-calibrated matching device collected in step S2 with the standard impedance range database established in step S1, determining the effective working interval of the capacitance, and obtaining the minimum effective percentage C_min and the maximum effective percentage C_max of the capacitance;

[0012] S4, writing C_min and C_max as limit values into the control software or hardware configuration of the to-be-calibrated matching device, limiting the adjustment range of the capacitance of the matching device to the interval [C_min, C_max] when the matching device is normally working.

[0013] Preferably, in step S1, the following steps are specifically included:

[0014] S1.1, first, a standard matching device meeting the design standard is selected, and the input end of the standard matching device is connected to a 50-ohm load and the output end is connected to a network analyzer;

[0015] S1.2, the network analyzer is configured to work in Smith chart mode and is set to display the real part Zr and the imaginary part Zx of the impedance;

[0016] S1.3, by a control program, at least one variable capacitance of the standard matching device is driven to scan from its minimum value to its maximum value with a preset step;

[0017] S1.4, at each capacitance percentage position, the stable impedance value (Zr, Zx) measured by the network analyzer is recorded to form an impedance track covering the entire capacitance adjustment range;

[0018] S1.5, the area covered by the impedance track or the area defined by the key boundary points thereof is stored as a standard impedance range database.

[0019] Preferably, in step S1.5, the standard impedance range database is the area covered by the impedance track.

[0020] Preferably, in step S2, the specific steps include:

[0021] S2.1, the to-be-calibrated matching device is replaced with the standard matching device, and the connection mode of keeping the input end connected to the 50-ohm load and the output end connected to the network analyzer is kept unchanged;

[0022] S2.2, by a control program, the corresponding variable capacitance of the to-be-calibrated matching device is driven to scan the entire range from its minimum value to its maximum value with the same or finer step as in step S1, and the impedance value (Zr, Zx) corresponding to each capacitance percentage position is automatically recorded.

[0023] Preferably, in step S3, the specific steps include:

[0024] S3.1, comparing the impedance data of the to-be-calibrated matching device collected in step S2 with the standard impedance range database established in step S1;

[0025] S3.2, analyzing the impedance trajectory of the to-be-calibrated matching device to find the part falling into the region defined by the standard impedance range database;

[0026] S3.3, determining the capacitance percentage range corresponding to the effective impedance trajectory part to obtain C_min and C_max.

[0027] Preferably, in step S4, the adjustment range of the capacitance of the to-be-calibrated matching device is limited to the interval [C_min, C_max] when the to-be-calibrated matching device is working normally.

[0028] The application also provides an impedance range automatic calibration system of a radio frequency matching device, which is applied to the above method and comprises:

[0029] a standard impedance measurement unit for connecting a standard matching device, a load and a network analyzer and performing automatic collection of standard impedance data;

[0030] an automatic control and data processing unit, usually a computer or an embedded controller installed with a control program;

[0031] a calibration execution unit for configuring the calculated limiting value to the control system of the to-be-calibrated matching device.

[0032] Preferably, the automatic control and data processing unit is used for:

[0033] controlling a stepping motor or a driving circuit of a variable capacitance to realize accurate control of the capacitance position and simultaneously used for communicating with the vector network analyzer through a network interface (such as GPIB, LAN and USB) to automatically read impedance data;

[0034] storing and processing the collected data to establish a standard impedance range database;

[0035] performing comparison and analysis of the data of the to-be-calibrated matching device with the standard database to calculate C_min and C_max.

[0036] Compared with the prior art, the application has the following beneficial effects:

[0037] 1. The application is fully automated, the whole calibration process is controlled by a program, manual intervention is not needed, production efficiency is significantly improved, and a large amount of working hours is saved.

[0038] 2、The present application has high precision and high consistency, through precise step scanning and computer comparison, human error is eliminated, and the matching range of each factory matching device is consistent with the standard device, which improves the product quality.

[0039] 3、The data driving of the present application is comprehensive and reliable, and through dense sampling of the full range of capacitors, the complete boundary of the matching range can be accurately described, the calibration result is more scientific and comprehensive, and the omissions of manual calibration are avoided.

[0040] 4、The present application is easy to realize and integrate, the method in the present application is based on general test instrument (network analyzer) and programmable control, without complex special hardware, which is convenient for modification and integration on existing production line. BRIEF DESCRIPTION OF DRAWINGS

[0041] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, which together with the embodiments of the present application, are used to explain the present application, and do not constitute a limitation of the present application.

[0042] In the drawings:

[0043] Figure 1 is a flowchart of the impedance automatic calibration method of the present application;

[0044] Figure 2 is a schematic diagram of the step of establishing a standard impedance range database of the present application;

[0045] Figure 3 is a structural block diagram of the automatic calibration system of the present application. DETAILED DESCRIPTION

[0046] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and do not limit the present application.

[0047] Embodiment: As shown in the figure, an impedance range automatic calibration method of a radio frequency matching device comprises the following steps: Figure 1

[0048] S1、establish a standard impedance range database; as shown in the figure, specifically comprising the following steps: Figure 2

[0049] S1.1, first, select a standard matching device with performance meeting the design standard, connect the input end of the standard matching device to a 50 ohm load, and connect the output end to a network analyzer;

[0050] S1.2, configure the network analyzer to work in Smith chart mode, and set to display the real part Zr and the imaginary part Zx of the impedance;

[0051] ​​S1.3. Through the control program, at least one variable capacitor of the standard matching unit is driven to scan from its minimum value to its maximum value in a preset step. In this embodiment, the preset step is set to 1%.

[0052] S1.4 At each capacitance percentage position, record the stable impedance value (Zr, Zx) measured by the network analyzer to form an impedance trajectory covering the entire capacitance adjustment range;

[0053] S1.5. Store the region covered by the impedance trajectory or the region defined by its key boundary points as a standard impedance range database, wherein the standard impedance range database is the region covered by the impedance trajectory.

[0054] S2. Perform an automatic impedance scan on the matched circuit to be calibrated. The specific steps include:

[0055] S2.1 Replace the standard matching unit with the matching unit to be calibrated, keeping the connection method of connecting the input terminal to a 50-ohm load and the output terminal to the network analyzer unchanged;

[0056] S2.2. Through the control program, drive the corresponding variable capacitor of the matching unit to be calibrated from its minimum value to its maximum value, and perform a full scan with the same or finer steps as in step S1, and automatically record the impedance value (Zr, Zx) corresponding to each capacitance percentage position.

[0057] S3. Determine the effective operating range of the capacitor, and obtain the minimum effective percentage C_min and the maximum effective percentage C_max; the specific steps include:

[0058] S3.1 Compare the impedance data of the matching device to be calibrated collected in step S2 with the standard impedance range database established in step S1;

[0059] S3.2 Analyze the impedance trajectory of the matching device to be calibrated and find the portion that falls within the area defined by the standard impedance range database;

[0060] S3.3 Determine the capacitance percentage range corresponding to the effective impedance trajectory portion to obtain C_min and C_max.

[0061] S4. Write C_min and C_max as limit values ​​into the control software or hardware configuration of the matching device to be calibrated. When the matching device to be calibrated is working normally, the adjustment range of its capacitance is limited to the interval [C_min, C_max].

[0062] The automatic impedance range calibration method for this RF matching device first utilizes a standard matching device that meets design standards. With a standard load connected to the input and a network analyzer connected to the output, and a specific configuration of the network analyzer, the variable capacitor of the standard matching device is driven to scan and record impedance data, establishing a standard impedance range database. Subsequently, the matching device to be calibrated is subjected to the same or more refined impedance scan using the same connection method, and the data is recorded. Then, by comparing the impedance data of the matching device to be calibrated with the standard database, the portion of its impedance trajectory that falls within the standard area is analyzed to determine the effective operating range of the capacitor, i.e., the minimum and maximum effective percentages. Finally, this effective range is written as a limit into the control configuration of the matching device to be calibrated, limiting its capacitance adjustment range during normal operation.

[0063] like Figure 3 As shown, the present invention also provides an automatic impedance range calibration system for an RF matching circuit, applied to the above method, comprising:

[0064] Standard impedance measurement unit: used to connect standard matching devices, loads, and network analyzers, and to perform automatic acquisition of standard impedance data;

[0065] Automatic control and data processing unit: typically a computer or embedded controller with control programs installed; the automatic control and data processing unit is used for:

[0066] The stepper motor or drive circuit controls the variable capacitor to achieve precise control of the capacitor position; it also communicates with a vector network analyzer via a network interface (such as GPIB, LAN, USB) to automatically read impedance data; it stores and processes the acquired data to establish a standard impedance range database; and it performs comparative analysis between the data of the matched device to be calibrated and the standard database to calculate C_min and C_max. The calibration execution unit configures the calculated limit values ​​into the control system of the matched device to be calibrated.

[0067] This invention automates calibration through a standardized database and automated scanning and comparison process, reducing human intervention errors and improving calibration consistency and accuracy. At the same time, it clarifies the effective working range of the capacitor and sets limits to ensure that the matching device is adjusted only within the impedance range that meets the design standards, optimizing working performance, avoiding ineffective adjustments, enhancing stability and reliability, simplifying operation steps, improving calibration efficiency, and facilitating large-scale application in production and maintenance.

[0068] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for automatic calibration of impedance range of a radio frequency (RF) match, comprising: The method comprises the following steps: ​ S1, establishing a standard impedance range database; S2, performing automatic impedance scanning on the to-be-calibrated matching device; S3, comparing the impedance data of the to-be-calibrated matching device collected in step S2 with the standard impedance range database established in step S1, determining the effective working interval of the capacitor, and obtaining the minimum effective percentage C_min and the maximum effective percentage C_max of the capacitor; S4, writing C_min and C_max as limit values into the control software or hardware configuration of the to-be-calibrated matching device, and limiting the adjustment range of the capacitor of the matching device to the interval [C_min, C_max] when the matching device is normally working.

2. The method of claim 1, wherein: In step S1, the following steps are specifically included: S1.1, first, a standard matching device meeting the design standard is selected, and the input end of the standard matching device is connected to a load and the output end is connected to a network analyzer; S1.2, the network analyzer is configured to work in Smith chart mode and is set to display the real part Zr and the imaginary part Zx of the impedance; S1.3, at least one variable capacitor of the standard matching device is driven to scan from its minimum value to its maximum value at a preset step by a control program; S1.4, at each capacitor percentage position, the stable impedance value (Zr, Zx) measured by the network analyzer is recorded to form an impedance track covering the entire capacitor adjustment range; S1.5, the area covered by the impedance track or the area defined by the key boundary points thereof is stored as a standard impedance range database.

3. The method of claim 2, wherein: In step S1.5, the standard impedance range database is the area covered by the impedance track.

4. The method of claim 1, wherein: In step S2, the specific steps include: S2.1, the to-be-calibrated matching device is replaced with the standard matching device, and the connection mode of keeping the input end connected to the load and the output end connected to the network analyzer is unchanged; S2.2, the corresponding variable capacitor of the to-be-calibrated matching device is driven to scan from its minimum value to its maximum value at the same step as in step S1 by a control program, and the impedance value (Zr, Zx) corresponding to each capacitor percentage position is automatically recorded.

5. The method of claim 1, wherein: In step S3, the specific steps include: S3.1, the impedance data of the to-be-calibrated matching device collected in step S2 is compared with the standard impedance range database established in step S1; S3.2, the impedance track of the to-be-calibrated matching device is analyzed to find the part falling into the area defined by the standard impedance range database; S3.3, the capacitor percentage range corresponding to the effective impedance track part is determined to obtain C_min and C_max.

6. The method of claim 1, wherein: In step S4, the adjustment range of the capacitor of the to-be-calibrated matching device is limited to the interval [C_min, C_max] when the matching device is normally working.

7. An impedance range auto-calibration system for a radio frequency match, applied to the method of claim 1, characterized by, It comprises: a standard impedance measurement unit for connecting the standard matching device, the load and the network analyzer and performing automatic collection of standard impedance data; an automatic control and data processing unit, usually a computer or an embedded controller installed with a control program; a calibration execution unit for configuring the calculated limit values into the control system of the to-be-calibrated matching device.

8. The system for automatic calibration of impedance range of a radio frequency match according to claim 7, wherein: The automatic control and data processing unit is used for: The step motor or driving circuit controlling the variable capacitor realizes the accurate control of the capacitor position; meanwhile, it is used for communicating with the vector network analyzer through the network interface to automatically read the impedance data. The collected data are stored and processed to establish a standard impedance range database. The comparison and analysis of the data of the to-be-calibrated matching device and the standard database are performed to calculate C_min and C_max.

Images