A waveguide port S parameter calibration method and device based on the center of an inscribed circle

Abstract

The present invention provides a method and device for calibrating the S parameters of a waveguide port based on the center of an inscribed circle. The method comprises: obtaining a first reflection coefficient of a load calibration component. Obtaining a second reflection coefficient of the load calibration component under a first phase bias. Obtaining a third reflection coefficient of the load calibration component under a second phase bias. Calculating the coordinates of the center of the inscribed circle of a triangle formed by the first reflection coefficient, the second reflection coefficient and the third reflection coefficient in a Smith chart as the corrected reflection coefficient of the load calibration component. Calibrate the S parameters of the waveguide port of a vector network analyzer according to the corrected reflection coefficient. The present invention can obtain a correction value through the reflection coefficient of the load calibration component under different phase biases, and use the correction value as the reflection coefficient measured when the actual reflection coefficient of the load calibration component is 0, so as to correct the calibration error caused by the reflection coefficient of the load calibration component not being an ideal 0 during the waveguide port calibration process, and obtain a more accurate measurement result of the S parameters of the waveguide port.

Description

Technical Field

[0001] The present invention relates to the technical field of vector network analyzer calibration, and in particular to a waveguide port S parameter calibration method and device based on an inscribed circle center. Background Art

[0002] With the development of high-power microwave technology, waveguide devices that withstand high power are widely used. Vector network analyzers are used to measure the network parameters of waveguide devices, such as S parameters. Before measurement, the vector network analyzer needs to be systematically calibrated according to the port type of the waveguide device to be measured, in order to eliminate the system error of the vector network analyzer itself. The waveguide dimensions of waveguide devices that transmit electromagnetic waves of different frequencies are different. In order to accurately measure the network parameters of waveguide devices, waveguide calibration is required for the corresponding frequency band. For vector network analyzers with two waveguide ports, short-circuit calibration parts, λ / 4 offset short-circuit calibration parts, load calibration parts, and through calibration parts are usually used for calibration. According to the measurement results of each calibration part, the vector network analyzer is calibrated based on the twelve-term error model, in which the S parameters of the calibration parts used during the calibration process must be known. Usually, the reflection coefficient of the short-circuit calibration part Γ (Right now S 11 parameter) is defined as -1; the reflection coefficient of the load calibration Γ Defined as 0; the through calibration S 11 Parameters and S 22 The parameter is defined as 0, S 21 Parameters and S 12 The parameter is defined as 1; the definition of the λ / 4 offset short-circuit calibration component is defined as different data as the frequency changes.

[0003] During single-port load calibration, connect the load calibration piece to a port of the vector network analyzer and measure the reflection coefficient. During calibration, the theoretical reflection coefficient of the load calibration piece is usually defined as 0. The load calibration piece is made by inserting a sharp absorbing material into the waveguide cavity. Due to factors such as the non-ideal absorption performance of the absorbing material itself, deviations in manufacturing and assembly, the actual reflection coefficient of the load calibration piece is not the ideal 0, but a very small value. There is a deviation between the actual reflection coefficient of the load calibration piece and the theoretical reflection coefficient. Using the reflection coefficient measured when the actual reflection coefficient of the load calibration piece is not 0 as the reflection coefficient measured when the actual reflection coefficient of the load calibration piece is 0 to calibrate the vector network analyzer, affects the calibration accuracy of the vector network analyzer, and thus affects the accuracy of the S parameter measurement results in subsequent use. Summary of the invention

[0004] The embodiment of the present invention provides a waveguide port S-parameter calibration method and device based on the inscribed circle center to solve the problem that the deviation between the actual reflection coefficient of the load calibration component and the theoretical reflection coefficient affects the calibration accuracy of the vector network analyzer.

[0005] In a first aspect, an embodiment of the present invention provides a waveguide port S parameter calibration method based on an inscribed circle center, comprising:

[0006] The first reflection coefficient of the load calibration component without phase offset is obtained by measuring with a vector network analyzer.

[0007] A second reflection coefficient of the load calibration component under a first phase offset is obtained by measuring the load calibration component by a vector network analyzer.

[0008] A third reflection coefficient of the load calibration component under a second phase offset is obtained by measuring the load calibration component by a vector network analyzer, wherein the second phase offset is not equal to the first phase offset.

[0009] The coordinates of the center of the inscribed circle of the triangle formed by the first reflection coefficient, the second reflection coefficient and the third reflection coefficient in the Smith chart are calculated as the reflection coefficient corrected by the load calibration piece.

[0010] The S parameters of the waveguide port of the vector network analyzer are calibrated according to the reflection coefficient corrected by the load calibration component.

[0011] In a possible implementation, calculating the coordinates of the center of the inscribed circle of the triangle formed by the first reflection coefficient, the second reflection coefficient, and the third reflection coefficient in the Smith chart as the reflection coefficient corrected by the load calibration component includes:

[0012] calculate

[0013]

[0014]

[0015]

[0016]

[0017]

[0018]

[0019] As the reflection coefficient corrected by the load calibration, is the real part of the corrected reflection coefficient, is the imaginary part of the corrected reflection coefficient, is the real part of the first reflection coefficient, is the imaginary part of the first reflection coefficient, is the real part of the second reflection coefficient, is the imaginary part of the second reflection coefficient, is the real part of the third reflection coefficient, is the imaginary part of the third reflection coefficient.

[0020] In a possible implementation, the first phase offset is λ / 6, and the second phase offset is λ / 3, where λ is the wavelength corresponding to the center frequency of the waveguide port S parameter calibration frequency band.

[0021] In a possible implementation, the step of obtaining a second reflection coefficient of the load calibration component under a first phase bias measured by a vector network analyzer includes:

[0022] The load calibration component cascaded with the λ / 6 waveguide transmission line is measured by a vector network analyzer to obtain a second reflection coefficient of the load calibration component under a first phase bias.

[0023] The step of obtaining a third reflection coefficient of the load calibration component under a second phase bias measured by a vector network analyzer comprises:

[0024] The load calibration component cascaded with the λ / 3 waveguide transmission line is measured by a vector network analyzer to obtain the third reflection coefficient of the load calibration component under the second phase bias.

[0025] In a possible implementation, calibrating the S parameters of the waveguide port of the vector network analyzer according to the reflection coefficient corrected by the load calibration component includes:

[0026] Get the short-circuit reflection coefficient of the short-circuit calibration component measured by a vector network analyzer.

[0027] Obtain the λ / 4 offset short-circuit reflection coefficient of the λ / 4 offset short-circuit calibration component measured by a vector network analyzer.

[0028] According to the reflection coefficient, short-circuit reflection coefficient and λ / 4 bias short-circuit reflection coefficient corrected by the load calibration component, the directivity error, source matching error and reflection tracking error of the waveguide port of the vector network analyzer are obtained.

[0029] The S parameters of the waveguide port of the vector network analyzer are calibrated according to the directivity error, source matching error and reflection tracking error.

[0030] In a second aspect, an embodiment of the present invention provides a waveguide port S parameter calibration device based on the inscribed circle center, comprising:

[0031] The first acquisition module is used to acquire a first reflection coefficient of the load calibration component without phase bias measured by a vector network analyzer.

[0032] The second acquisition module is used to acquire a second reflection coefficient of the load calibration component under a first phase bias measured by a vector network analyzer.

[0033] The third acquisition module is used to acquire a third reflection coefficient of the load calibration component under a second phase offset measured by a vector network analyzer, wherein the second phase offset is not equal to the first phase offset.

[0034] The calculation module is used to calculate the coordinates of the center of the inscribed circle of the triangle formed by the first reflection coefficient, the second reflection coefficient and the third reflection coefficient in the Smith chart as the reflection coefficient corrected by the load calibration component.

[0035] The calibration module is used to calibrate the S parameters of the waveguide port of the vector network analyzer according to the reflection coefficient corrected by the load calibration component.

[0036] In a possible implementation, the calculation module is specifically used to calculate

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043] As the reflection coefficient corrected by the load calibration, is the real part of the corrected reflection coefficient, is the imaginary part of the corrected reflection coefficient, is the real part of the first reflection coefficient, is the imaginary part of the first reflection coefficient, is the real part of the second reflection coefficient, is the imaginary part of the second reflection coefficient, is the real part of the third reflection coefficient, is the imaginary part of the third reflection coefficient.

[0044] In a possible implementation, the first phase offset is λ / 6, and the second phase offset is λ / 3, where λ is the wavelength corresponding to the center frequency of the waveguide port S parameter calibration frequency band.

[0045] In a possible implementation, the second acquisition module is specifically configured to measure a load calibration component cascaded with a λ / 6 waveguide transmission line through a vector network analyzer to acquire a second reflection coefficient of the load calibration component under a first phase bias.

[0046] The third acquisition module is specifically used to measure the load calibration component cascaded with the λ / 3 waveguide transmission line through a vector network analyzer to obtain the third reflection coefficient of the load calibration component under the second phase bias.

[0047] In a possible implementation, the calibration module includes

[0048] The short-circuit reflection coefficient acquisition unit is used to acquire the short-circuit reflection coefficient of the short-circuit calibration component measured by the vector network analyzer.

[0049] The λ / 4 offset short circuit reflection coefficient acquisition unit is used to acquire the λ / 4 offset short circuit reflection coefficient of the λ / 4 offset short circuit calibration piece measured by a vector network analyzer.

[0050] The error calculation unit is used to obtain the directivity error, source matching error and reflection tracking error of the waveguide port of the vector network analyzer according to the reflection coefficient, short-circuit reflection coefficient and λ / 4 bias short-circuit reflection coefficient corrected by the load calibration component.

[0051] The calibration unit is used to calibrate the S parameters of the waveguide port of the vector network analyzer according to the directivity error, source matching error and reflection tracking error.

[0052] In a third aspect, an embodiment of the present invention provides a calibration device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the waveguide port S parameter calibration method based on the center of an inscribed circle as described in the first aspect or any possible implementation of the first aspect are implemented.

[0053] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the waveguide port S parameter calibration method based on the center of the inscribed circle as described in the first aspect or any possible implementation method of the first aspect are implemented.

[0054] The embodiment of the present invention provides a waveguide port S parameter calibration method and device based on the inscribed circle center, the method comprising obtaining a first reflection coefficient of a load calibration component measured by a vector network analyzer without phase bias. Obtaining a second reflection coefficient of the load calibration component measured by the vector network analyzer under a first phase bias. Obtaining a third reflection coefficient of the load calibration component measured by the vector network analyzer under a second phase bias, wherein the second phase bias is not equal to the first phase bias. Calculating the coordinates of the center of the inscribed circle of the triangle formed by the first reflection coefficient, the second reflection coefficient and the third reflection coefficient in the Smith chart as the corrected reflection coefficient of the load calibration component. Calibrate the S parameters of the waveguide port of the vector network analyzer according to the corrected reflection coefficient of the load calibration component. By measuring the reflection coefficient of the load calibration component under different phase biases, taking the coordinates of the center of the inscribed circle of the triangle formed by each reflection coefficient as a correction value, and taking the correction value as the reflection coefficient measured when the actual reflection coefficient of the load calibration component is 0, the calibration error caused by the reflection coefficient of the load calibration component not being an ideal 0 in the prior art waveguide port calibration process is corrected, thereby obtaining a more accurate waveguide port S parameter measurement result. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0056] Figure 1 is a schematic diagram of the forward transmission error model of the twelve-term error model;

[0057] Figure 2 is a schematic diagram of the reverse transmission error model of the twelve-term error model;

[0058] Figure 3 It is a schematic diagram of waveguide port isolation calibration of a vector network analyzer;

[0059] Figure 4 This is a schematic diagram of the waveguide port through calibration of a vector network analyzer;

[0060] Figure 5 It is a schematic diagram of measuring DUT with a vector network analyzer;

[0061] Figure 6 It is a schematic diagram of the internal structure of the load calibration component;

[0062] Figure 7 It is a flow chart of an implementation method of a waveguide port S parameter calibration method based on the inscribed circle center provided by an embodiment of the present invention;

[0063] Figure 8 It is a schematic diagram of single-port load calibration of a waveguide port of a vector network analyzer provided in an embodiment of the present invention;

[0064] Fig. 9 is a schematic structural diagram of a waveguide transmission line provided by an embodiment of the present invention;

[0065] Fig.10 The Smith chart provided by the embodiment of the present invention Γ Load_M Schematic diagram of the method for obtaining ;

[0066] Fig.11 is a schematic structural diagram of a short-circuit calibration component provided by an embodiment of the present invention;

[0067] Fig.12 It is a schematic diagram of single-port short-circuit calibration of a waveguide port of a vector network analyzer provided in an embodiment of the present invention;

[0068] Fig.13 It is a schematic diagram of single-port λ / 4 bias short-circuit calibration of a waveguide port of a vector network analyzer provided by an embodiment of the present invention;

[0069] Fig.14 1 is a schematic structural diagram of a waveguide port S parameter calibration device based on the inscribed circle center provided in an embodiment of the present invention;

[0070] Fig.15 is a schematic diagram of a calibration device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0071] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0072] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0073] With the development of high-power microwave technology, waveguide devices that withstand high power are widely used. Vector network analyzers are used to measure the network parameters of waveguide devices, such as S parameters. Before measurement, the vector network analyzer needs to be systematically calibrated according to the port type of the waveguide device to be measured, in order to eliminate the system error of the vector network analyzer itself. The waveguide sizes of waveguide devices that transmit electromagnetic waves of different frequencies are different. In practical applications, it is difficult to configure waveguide calibration parts and corresponding calibration procedures for all frequency bands. At the same time, the lower the working frequency band of the waveguide device, the larger the waveguide size, and the worse the operability. In order to accurately measure the network parameters of the waveguide device, it is necessary to perform waveguide calibration for the corresponding frequency band of the vector network analyzer.

[0074] Different from the calibration of coaxial vector network analyzers, waveguide two-port vector network analyzers are usually calibrated using short-circuit calibration components, λ / 4 offset short-circuit calibration components (λ / 4 transmission line cascade short-circuit calibration components), load calibration components, and through calibration components. During the calibration process, the S parameters of the calibration components used must be known. Usually, the reflection coefficient Γ of the short-circuit calibration component, that is, S 11 , defined as -1; the reflection coefficient of the load calibration piece Γ, that is, S 11 , defined as 0; S 11 and S 22 Defined as 0, S 21 and S 12 The definition of the λ / 4 offset short-circuit calibration piece is defined as different data as the frequency changes. According to the measurement results of each calibration piece, the vector network analyzer is calibrated based on the twelve-term error model.

[0075] Figure 1 It is a schematic diagram of the forward transmission error model of the twelve-term error model. Figure 2 This is a schematic diagram of the reverse transmission error model of the twelve-term error model. Figure 1 and Figure 2 :

[0076] The forward transmission error model includes 6 error terms, namely: forward directivity error (EDF), forward source matching error (ESF), forward reflection tracking error (ERF), forward isolation error (EXF), forward load matching error (ELF) and forward transmission tracking error (ETF). The reverse transmission error model includes 6 error terms, namely: reverse directivity error EDR, reverse source matching error ESR, reverse reflection tracking error ERR, reverse isolation error EXR, reverse load matching error ELR and reverse transmission tracking error ETR. Through the vector network analyzer waveguide port measurement calibration, twelve errors are obtained according to the measurement results. The vector network analyzer waveguide port measurement calibration includes single-port calibration, isolation calibration and through calibration.

[0077] The forward directivity error EDF, forward source matching error ESF, forward reflection tracking error ERF, reverse directivity error EDR, reverse source matching error ESR and reverse reflection tracking error ERR are obtained through single-port calibration.

[0078] Taking forward transmission as an example, three single-port calibration components are connected to the first port, namely the short-circuit calibration component, the λ / 4 offset short-circuit calibration component and the load calibration component. The three reflection coefficients are obtained by measuring the three single-port calibration components respectively. Γ ,Right now S 11 , that is, the short-circuit reflection coefficient Γ Short_M ,λ / 4 bias short circuit reflection coefficient Γ OffsetShort_M and load reflection coefficient Γ Load_M The actual reflection coefficients of the short-circuit calibration component, the λ / 4 offset short-circuit calibration component, and the load calibration component are Γ The values ​​are known in advance and are recorded as Γ Short_A , Γ OffsetShort_A and Γ Load_A The forward directivity error EDF, forward source matching error ESF and forward reflection tracking error ERF in the forward transmission error model can be obtained by the following formula.

[0079]

[0080] Taking reverse transmission as an example, three single-port calibration components, namely the short-circuit calibration component, the λ / 4 bias short-circuit calibration component and the load calibration component, are connected to the second port respectively, and the corresponding reflection coefficients are measured. The reverse directivity error EDR, reverse source matching error ESR and reverse reflection tracking error ERR in the reverse transmission error model can be obtained using the same calculation method as above.

[0081] The error EXF and the error EXR are obtained through isolation calibration. Figure 3 This is a schematic diagram of the waveguide port isolation calibration of the vector network analyzer. Figure 3 :Connect the load calibration components to both the first and second ports of the vector network analyzer. The transmission coefficient obtained by measurement is S 21 and S 12 Denoted as S 21 Load and S 12 Load . EXF and EXR can be obtained according to the following formula.

[0082]

[0083]

[0084] Another simplified method is that, usually, EXF and EXR are very small and can be ignored, so EXF and EXR can be directly considered to be 0 without being measured as above.

[0085] The ELF and ETF in the forward transmission error model and the ELR and ETR in the reverse transmission error model are obtained through through-calibration. Figure 4 This is a schematic diagram of the waveguide port direct calibration of the vector network analyzer. Figure 4 :The first and second ports of the vector network analyzer are directly connected to each other through a through calibration piece. The S parameters measured by the vector network analyzer are recorded as S Thru_M ,include S 11 Thru_M , S 21 Thru_M , S 12 Thru_M and S 22 Thru_M Four S parameters. ELF and ETF in the forward transmission error model and ELR and ETR in the reverse transmission error model can be obtained by the following formula.

[0086]

[0087]

[0088]

[0089]

[0090] Through the above single-port calibration, isolation calibration and through calibration process, the values ​​of all twelve errors in the forward transmission error model and the reverse transmission error model are obtained. These twelve error values ​​are the twelve system errors of the vector network analyzer.

[0091] By combining the above twelve systematic errors with the twelve error models, the measured value of the measured device is corrected to obtain the corrected true value of the measured device. Figure 5 This is a schematic diagram of a vector network analyzer measuring a DUT. Figure 5 :Connect the device under test (DUT) to the first and second ports of the vector network analyzer. The original S parameter data of the DUT, that is, the uncorrected S parameter of the DUT, can be obtained by measurement, which is recorded as S MThe real S parameters of the DUT, that is, the corrected S parameters of the DUT, are recorded as S A , the real S parameters of the DUT can be obtained by the following formula:

[0092]

[0093]

[0094]

[0095]

[0096] in,

[0097]

[0098]

[0099]

[0100]

[0101]

[0102] In the above calibration method, since the actual reflection coefficient of the load calibration component is not ideally 0, the calibration accuracy is affected. Figure 6 This is a schematic diagram of the internal structure of the load calibration component. Figure 6 :The load calibration piece is made by inserting a wedge-shaped absorbing material 12 into a waveguide cavity 11. One end of the load calibration piece waveguide cavity 11 is closed. During single-port load calibration, the unclosed end of the load calibration piece is connected to a port of the vector network analyzer to measure the reflection coefficient. During calibration, the theoretical reflection coefficient of the load calibration piece is usually defined as 0. Due to factors such as the unsatisfactory absorption performance of the absorbing material 12 itself, deviations in manufacturing and assembly, etc., the actual reflection coefficient of the load calibration piece is not the ideal 0, but a very small value. There is a deviation between the actual reflection coefficient of the load calibration piece and the theoretical reflection coefficient. Using the reflection coefficient measured when the actual reflection coefficient of the load calibration piece is not 0 as the reflection coefficient measured when the actual reflection coefficient of the load calibration piece is 0 to calibrate the vector network analyzer affects the calibration accuracy of the vector network analyzer, thereby affecting the accuracy of the S parameter measurement results in subsequent use.

[0103] The embodiment of the present invention provides a waveguide port S-parameter calibration method based on the inscribed circle center to solve the problem that the deviation between the actual reflection coefficient of the load calibration component and the theoretical reflection coefficient affects the calibration accuracy of the vector network analyzer.

[0104] Figure 7FIG. 1 is a flow chart of an implementation method of a waveguide port S parameter calibration method based on an inscribed circle center provided by an embodiment of the present invention. Figure 7 : Calibration methods include:

[0105] In step S1, a first reflection coefficient of a load calibration component without phase bias is obtained by measuring with a vector network analyzer.

[0106] The first reflection coefficient of the load calibration component is measured without phase bias, that is, the load calibration component is directly connected to a waveguide port of the vector network analyzer for measurement. One end of the load calibration component is closed, and the other end is provided with a waveguide port, and an absorbing material 12 is provided inside. During single-port calibration, a waveguide port of the vector network analyzer is connected to the waveguide port of the load calibration component. Figure 8 Schematic diagram of single-port load calibration of waveguide port of vector network analyzer provided by an embodiment of the present invention. Figure 8 : The waveguide port of the vector network analyzer emits an electromagnetic wave and inputs the waveguide port of the load calibration component. The electromagnetic wave is absorbed by the absorbing material 12 and then reflected at the closed end of the load calibration component, and then absorbed by the absorbing material 12 again and then reflected back to the waveguide port of the vector network analyzer.

[0107] The reflection coefficient is the complex ratio of the reflected wave amplitude to the incident wave amplitude. The incident wave amplitude is the incident wave amplitude received by the load calibration component from the waveguide port of the vector network analyzer. The reflected wave amplitude is the reflected wave amplitude reflected back by the load calibration component. Theoretically, the reflected wave amplitude is 0, that is, the electromagnetic wave is completely absorbed by the absorbing material 12. In practice, due to the imperfect load calibration component, the electromagnetic wave is not completely absorbed.

[0108] In step S2, a second reflection coefficient of the load calibration component under a first phase offset measured by a vector network analyzer is obtained. Exemplarily, the first phase offset is not zero.

[0109] In step S3, a third reflection coefficient of the load calibration component under a second phase offset measured by a vector network analyzer is obtained, wherein the second phase offset is not equal to the first phase offset. Exemplarily, the second phase offset is not zero.

[0110] Exemplarily, the phase offset is achieved by adding a waveguide transmission line between the load calibration component and the vector network analyzer. Fig. 9 Schematic diagram of the structure of the waveguide transmission line provided by the embodiment of the present invention. Fig. 9 : In the figure, a and b are waveguide transmission lines of different lengths, and c is a load calibration component. The port of the waveguide transmission line is consistent with the specifications of the waveguide port of the load calibration component and the vector network analyzer. When measuring, the load calibration component, the waveguide transmission line and the vector network analyzer are connected in sequence. The length of the waveguide transmission line in the transmission direction corresponds to the center frequency of the calibration band.

[0111] Exemplarily, the first phase offset is greater than 0 and less than λ / 2, and the second phase offset is greater than 0 and less than λ / 2. Exemplarily, the first phase offset is λ / 4, and the second phase offset is λ3 / 8. Exemplarily, the first phase offset is λ / 8, and the second phase offset is λ3 / 8.

[0112] In a possible implementation, the first phase offset is λ / 6, and the second phase offset is λ / 3, where λ is the wavelength corresponding to the center frequency of the waveguide port S parameter calibration frequency band.

[0113] In a possible implementation, obtaining a second reflection coefficient of a load calibration component under a first phase bias measured by a vector network analyzer includes:

[0114] The load calibration component cascaded with the λ / 6 waveguide transmission line is measured by a vector network analyzer to obtain a second reflection coefficient of the load calibration component under a first phase bias.

[0115] Obtaining a third reflection coefficient of the load calibration component under a second phase bias measured by a vector network analyzer, comprising:

[0116] The load calibration component cascaded with the λ / 3 waveguide transmission line is measured by a vector network analyzer to obtain the third reflection coefficient of the load calibration component under the second phase bias.

[0117] Exemplarily, the specifications of the λ / 3 waveguide transmission line and the λ / 6 waveguide transmission line are obtained according to the specifications of the waveguide port and the center frequency of the calibration frequency band. Exemplarily, the waveguide port adopts a rectangular square waveguide of WR-10 specification, the calibration frequency range is 75GHz~110GHz, and the inner cavity cross-sectional size of the waveguide cavity 11 of the waveguide port is 0.1in×0.05in, that is, 2.54mm×1.27mm. Using the LineCalc tool in the ADS software, it is calculated that the lengths of the λ / 3 waveguide transmission line and the λ / 6 waveguide transmission line of the rectangular square waveguide of this specification are 1.5mm and 0.75mm respectively.

[0118] In step S4, the coordinates of the center of the inscribed circle of the triangle formed by the first reflection coefficient, the second reflection coefficient and the third reflection coefficient in the Smith chart are calculated as the reflection coefficient after correction of the load calibration component.

[0119] The Smith chart is also called the impedance chart. It is formed by superimposing the normalized equal resistance circle and the normalized equal reactance circle on the complex plane of the reflection coefficient. The Smith chart contains the complex plane. The reflection coefficient is a complex number, corresponding to the coordinates of a certain point in the complex plane. The real part of the reflection coefficient corresponds to the horizontal axis of the complex plane, and the imaginary part of the reflection coefficient corresponds to the vertical axis of the complex plane. Fig.10 is Γ on the Smith chart provided by the embodiment of the present invention Load_MSchematic diagram of the method for obtaining . Fig.10 :Three different reflection coefficients correspond to three points in the complex plane, forming a triangle. The reflection coefficient corresponding to the coordinates of the center of the inscribed circle of the triangle is used as the reflection coefficient corrected by the load calibration component. Exemplarily, the reflection coefficient corrected by the load calibration component is used to participate in the error term solution calculation of the twelve-term error model. Exemplarily, the reflection coefficient corrected by the load calibration component is used to participate in the solution calculation of the directional error, source matching error and reflection tracking error in the twelve-term error model.

[0120] In a possible implementation, calculating the coordinates of the center of the inscribed circle of the triangle formed by the first reflection coefficient, the second reflection coefficient and the third reflection coefficient in the Smith chart as the reflection coefficient corrected by the load calibration component includes: calculating

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127] As the reflection coefficient corrected by the load calibration, is the real part of the corrected reflection coefficient, is the imaginary part of the corrected reflection coefficient, is the real part of the first reflection coefficient, is the imaginary part of the first reflection coefficient, is the real part of the second reflection coefficient, is the imaginary part of the second reflection coefficient, is the real part of the third reflection coefficient, is the imaginary part of the third reflection coefficient.

[0128] In step S5, the S parameters of the waveguide port of the vector network analyzer are calibrated according to the reflection coefficient corrected by the load calibration component.

[0129] In a possible implementation, calibrating the S parameters of the waveguide port of the vector network analyzer according to the reflection coefficient corrected by the load calibration component includes:

[0130] Get the short-circuit reflection coefficient of the short-circuit calibration component measured by a vector network analyzer. Fig.11 Schematic diagram of the structure of the short-circuit calibration component provided in an embodiment of the present invention. Fig.11 FIG. d is a schematic diagram of the structure of the short-circuit calibration component provided in an embodiment of the present invention. Fig.12 The present invention is a schematic diagram of a single-port short-circuit calibration of a waveguide port of a vector network analyzer provided in an embodiment of the present invention. Fig.12 In the embodiment, the short-circuit calibration piece is connected to the waveguide port of the vector network analyzer to measure the short-circuit reflection coefficient.

[0131] Obtain the λ / 4 offset short-circuit reflection coefficient of the λ / 4 offset short-circuit calibration component measured by a vector network analyzer. Fig.11 Element e is a schematic diagram of the structure of a λ / 4 biased waveguide transmission line provided in an embodiment of the present invention. Fig.13 The present invention is a schematic diagram of a single-port λ / 4 bias short-circuit calibration of a waveguide port of a vector network analyzer provided in an embodiment of the present invention. Fig.13 In the embodiment, the short circuit calibration piece is connected to the λ / 4 bias waveguide transmission line to form a λ / 4 bias short circuit calibration piece. The λ / 4 bias short circuit calibration piece is then connected to the waveguide port of the vector network analyzer to measure and obtain the λ / 4 bias short circuit reflection coefficient.

[0132] According to the above corrected reflection coefficient, short-circuit reflection coefficient and λ / 4 bias short-circuit reflection coefficient, the directivity error, source matching error and reflection tracking error of the waveguide port of the vector network analyzer are obtained.

[0133] The S-parameters of the vector network analyzer waveguide port are calibrated based on directivity error, source matching error, and reflection tracking error.

[0134] An embodiment of the present invention provides a waveguide port S-parameter calibration method based on the inscribed circle center. By measuring the reflection coefficient of a load calibration component under different phase biases, the coordinates of the inscribed circle center of a triangle formed by each reflection coefficient are used as correction values. The correction values ​​are used as the reflection coefficient measured when the actual reflection coefficient of the load calibration component is 0. This corrects the calibration error caused by the reflection coefficient of the load calibration component not being an ideal 0 in the waveguide port calibration process of the prior art, thereby achieving more accurate calibration, improving the measurement accuracy of the waveguide port S-parameters, and thus obtaining more accurate waveguide port S-parameter measurement results.

[0135] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0136] The following is an embodiment of the device of the present invention. For details not described in detail therein, reference may be made to the corresponding method embodiment described above.

[0137] Fig.141 is a schematic diagram of the structure of a waveguide port S parameter calibration device based on the inscribed circle center provided by an embodiment of the present invention. For ease of explanation, only the parts related to the embodiment of the present invention are shown. Fig.14 The embodiment of the present invention provides a waveguide port S parameter calibration device 2 based on the inscribed circle center, comprising:

[0138] The first acquisition module 21 is used to acquire a first reflection coefficient of the load calibration component without phase bias measured by a vector network analyzer.

[0139] The second acquisition module 22 is used to acquire a second reflection coefficient of the load calibration component under a first phase bias measured by a vector network analyzer.

[0140] The third acquisition module 23 is used to acquire a third reflection coefficient of the load calibration component under a second phase offset measured by a vector network analyzer, wherein the second phase offset is not equal to the first phase offset.

[0141] The calculation module 24 is used to calculate the coordinates of the center of the inscribed circle of the triangle formed by the first reflection coefficient, the second reflection coefficient and the third reflection coefficient in the Smith chart as the reflection coefficient corrected by the load calibration component.

[0142] The calibration module 25 is used to calibrate the S parameters of the waveguide port of the vector network analyzer according to the reflection coefficient corrected by the load calibration component.

[0143] In a possible implementation, the calculation module 24 is specifically used to calculate

[0144]

[0145]

[0146]

[0147]

[0148]

[0149]

[0150] As the reflection coefficient corrected by the load calibration, is the real part of the corrected reflection coefficient, is the imaginary part of the corrected reflection coefficient, is the real part of the first reflection coefficient, is the imaginary part of the first reflection coefficient, is the real part of the second reflection coefficient, is the imaginary part of the second reflection coefficient, is the real part of the third reflection coefficient, is the imaginary part of the third reflection coefficient.

[0151] In a possible implementation, the first phase offset is λ / 6, and the second phase offset is λ / 3, where λ is the wavelength corresponding to the center frequency of the waveguide port S parameter calibration frequency band.

[0152] In a possible implementation, the second acquisition module 22 is specifically configured to measure a load calibration component cascaded with a λ / 6 waveguide transmission line through a vector network analyzer to obtain a second reflection coefficient of the load calibration component under a first phase bias.

[0153] The third acquisition module 23 is specifically configured to measure a load calibration component cascaded with a λ / 3 waveguide transmission line by using a vector network analyzer to obtain a third reflection coefficient of the load calibration component under a second phase bias.

[0154] In a possible implementation, the calibration module 25 includes

[0155] The short-circuit reflection coefficient acquisition unit is used to acquire the short-circuit reflection coefficient of the short-circuit calibration component measured by the vector network analyzer.

[0156] The λ / 4 offset short circuit reflection coefficient acquisition unit is used to acquire the λ / 4 offset short circuit reflection coefficient of the λ / 4 offset short circuit calibration piece measured by a vector network analyzer.

[0157] The error calculation unit is used to obtain the directivity error, source matching error and reflection tracking error of the waveguide port of the vector network analyzer according to the reflection coefficient, short-circuit reflection coefficient and λ / 4 bias short-circuit reflection coefficient corrected by the load calibration component.

[0158] Calibration unit for calibrating the S-parameters of the vector network analyzer waveguide ports based on directivity error, source matching error and reflection tracking error.

[0159] Fig.15 Schematic diagram of a calibration device provided by an embodiment of the present invention. Fig.15 As shown, the calibration device 3 of this embodiment includes: a processor 30, a memory 31, and a computer program 32 stored in the memory 31 and executable on the processor 30. When the processor 30 executes the computer program 32, the steps in the above-mentioned waveguide port S parameter calibration method based on the inscribed circle center are implemented, for example Figure 7 Alternatively, when the processor 30 executes the computer program 32, the functions of each module / unit in the above-mentioned device embodiments are realized, for example Fig.14 The functions of modules 21 to 25 are shown.

[0160] Exemplarily, the computer program 32 may be divided into one or more modules / units, which are stored in the memory 31 and executed by the processor 30 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program 32 in the calibration device 3. For example, the computer program 32 may be divided into Fig.14 Modules 21 to 25 are shown.

[0161] The calibration device 3 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The calibration device 3 may include, but is not limited to, a processor 30 and a memory 31. Those skilled in the art will appreciate that Fig.15 It is only an example of the calibration device 3 and does not constitute a limitation of the calibration device 3. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the calibration device may also include input and output devices, network access devices, buses, etc.

[0162] The processor 30 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0163] The memory 31 may be an internal storage unit of the calibration device 3, such as a hard disk or memory of the calibration device 3. The memory 31 may also be an external storage device of the calibration device 3, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the calibration device 3. Further, the memory 31 may also include both an internal storage unit and an external storage device of the calibration device 3. The memory 31 is used to store the computer program and other programs and data required by the calibration device. The memory 31 may also be used to temporarily store data that has been output or is to be output.

[0164] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0165] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0166] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0167] In the embodiments provided by the present invention, it should be understood that the disclosed device / calibration device and method can be implemented in other ways. For example, the device / calibration device embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0168] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0169] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0170] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned waveguide port S parameter calibration method based on the center of the inscribed circle can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium.

[0171] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A waveguide port S parameter calibration method based on the inscribed circle center, characterized in that: The method comprises: Obtaining a first reflection coefficient of the load calibration component without phase bias measured by a vector network analyzer; Acquire a second reflection coefficient of the load calibration component under a first phase bias measured by a vector network analyzer; Acquire a third reflection coefficient of the load calibration component under a second phase offset measured by a vector network analyzer, wherein the second phase offset is not equal to the first phase offset; Calculate the coordinates of the center of the inscribed circle of the triangle formed by the first reflection coefficient, the second reflection coefficient and the third reflection coefficient in the Smith chart as the reflection coefficient corrected by the load calibration component; The S parameters of the waveguide port of the vector network analyzer are calibrated according to the reflection coefficient corrected by the load calibration component.

2. A waveguide port S parameter calibration method based on the inscribed circle center according to claim 1, characterized in that: The step of calculating the coordinates of the center of the inscribed circle of the triangle formed by the first reflection coefficient, the second reflection coefficient and the third reflection coefficient in the Smith chart as the reflection coefficient corrected by the load calibration component includes: calculate Γ Load_M =Re Load_M +And Load_M Γ Load_M As the reflection coefficient corrected by the load calibration, Re Load_M is the real part of the corrected reflection coefficient, Im Load_M is the imaginary part of the corrected reflection coefficient, Re Load_M1 is the real part of the first reflection coefficient, Im Load_M1 is the imaginary part of the first reflection coefficient, Re Load_M2 is the real part of the second reflection coefficient, Im Load_M2 is the imaginary part of the second reflection coefficient, Re Load_M3 is the real part of the third reflection coefficient, Im Load_M3 is the imaginary part of the third reflection coefficient.

3. The waveguide port S parameter calibration method based on the inscribed circle center according to claim 1, characterized in that: The first phase offset is λ / 6, and the second phase offset is λ / 3, wherein λ is the wavelength corresponding to the center frequency of the waveguide port S parameter calibration frequency band.

4. The method for calibrating the S parameters of a waveguide port based on the inscribed circle center according to claim 3, characterized in that: The step of obtaining a second reflection coefficient of the load calibration component under a first phase bias measured by a vector network analyzer comprises: Measuring a load calibration component cascaded with a λ / 6 waveguide transmission line by a vector network analyzer to obtain a second reflection coefficient of the load calibration component under a first phase bias; The step of obtaining a third reflection coefficient of the load calibration component under a second phase bias measured by a vector network analyzer comprises: The load calibration component cascaded with the λ / 3 waveguide transmission line is measured by a vector network analyzer to obtain the third reflection coefficient of the load calibration component under the second phase bias.

5. The waveguide port S parameter calibration method based on the inscribed circle center according to claim 1, characterized in that: The method of calibrating the S parameters of the waveguide port of the vector network analyzer according to the reflection coefficient corrected by the load calibration component comprises: Obtaining a short-circuit reflection coefficient of a short-circuit calibration component measured by a vector network analyzer; Obtaining a λ / 4 offset short-circuit reflection coefficient of a λ / 4 offset short-circuit calibration component measured by a vector network analyzer; Obtaining the directivity error, source matching error and reflection tracking error of the waveguide port of the vector network analyzer according to the reflection coefficient, short-circuit reflection coefficient and λ / 4 bias short-circuit reflection coefficient corrected by the load calibration component; The S parameters of the waveguide port of the vector network analyzer are calibrated according to the directivity error, source matching error and reflection tracking error.

6. A waveguide port S parameter calibration device based on the inscribed circle center, characterized in that: include: A first acquisition module is used to acquire a first reflection coefficient of the load calibration component measured by a vector network analyzer without phase bias; A second acquisition module is used to acquire a second reflection coefficient of the load calibration component under a first phase bias measured by a vector network analyzer; A third acquisition module is used to acquire a third reflection coefficient of the load calibration component under a second phase offset measured by a vector network analyzer, wherein the second phase offset is not equal to the first phase offset; A calculation module, used for calculating the coordinates of the center of the inscribed circle of the triangle formed by the first reflection coefficient, the second reflection coefficient and the third reflection coefficient in the Smith chart as the reflection coefficient corrected by the load calibration component; The calibration module is used to calibrate the S parameters of the waveguide port of the vector network analyzer according to the reflection coefficient corrected by the load calibration component.

7. The waveguide port S parameter calibration device based on the inscribed circle center according to claim 6, characterized in that: The calculation module is specifically used to calculate Γ Load_M =Re Load_M +And Load_M Γ Load_M As the reflection coefficient corrected by the load calibration, Re Load_M is the real part of the corrected reflection coefficient, Im Load_M is the imaginary part of the corrected reflection coefficient, Re Load_M1 is the real part of the first reflection coefficient, Im Load_M1 is the imaginary part of the first reflection coefficient, Re Load_M2 is the real part of the second reflection coefficient, Im Load_M2 is the imaginary part of the second reflection coefficient, Re Load_M3 is the real part of the third reflection coefficient, Im Load_M3 is the imaginary part of the third reflection coefficient.

8. The waveguide port S parameter calibration device based on the inscribed circle center according to claim 7, characterized in that: The first phase offset is λ / 6, and the second phase offset is λ / 3, wherein λ is the wavelength corresponding to the center frequency of the waveguide port S parameter calibration frequency band.

9. A calibration device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the waveguide port S parameter calibration method based on the inscribed circle center as described in any one of claims 1 to 5 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the waveguide port S parameter calibration method based on the inscribed circle center as described in any one of claims 1 to 5 are implemented.

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