Calibration method and dielectric constant measurement method of quasi-optical cavity dielectric constant measurement system

Abstract

This invention belongs to the field of electromagnetic technology, specifically disclosing a calibration method and a dielectric constant measurement method for a quasi-optical cavity dielectric constant measurement system. The calibration method includes: developing frequency response isolation calibration software, which includes transmission frequency response standard software developed for a transmission frequency response standard and isolation standard software developed for an isolation standard; when the transmission frequency response standard and the isolation standard are sequentially connected to the quasi-optical cavity dielectric constant measurement system, the transmission frequency response standard software and the isolation standard software are used respectively to perform transmission frequency response calibration and isolation calibration on the quasi-optical cavity dielectric constant measurement system to obtain transmission frequency response error and isolation error; and correcting the measurement performance error of the quasi-optical cavity dielectric constant measurement system based on the transmission frequency response error and the isolation error. This invention solves the problems of unstable resonant signal, low accuracy of quality factor measurement, and poor stability in quasi-optical cavity dielectric constant measurement systems.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic technology, specifically relating to a calibration method and a dielectric constant measurement method for a quasi-optical cavity dielectric constant measurement system. Background Technology

[0002] The quasi-optical cavity method is widely used in the field of dielectric constant measurement of materials due to its non-destructive nature and high measurement accuracy. The basic principle of existing quasi-optical cavity dielectric constant measurement systems using the quasi-optical cavity method is to derive the dielectric constant and loss tangent by comparing the changes in resonant frequency, working cavity length, and quality factor of the sample before and after it is placed in the quasi-optical cavity, combined with parameters such as the sample thickness and initial cavity length. Quasi-optical cavities have two structures: symmetrical and asymmetrical. The symmetrical structure uses two spherical mirrors, while the asymmetrical quasi-optical cavity uses one spherical mirror and one plane mirror. The asymmetrical quasi-optical cavity is easier to place the sample and has wider applications. Asymmetrical quasi-optical cavities have two coupling methods: single-aperture reflection and dual-aperture through-hole. The dual-aperture through-hole coupling method is more commonly used for two reasons: First, theoretically, for the same quasi-optical cavity, dual-aperture through-hole coupling has a higher quality factor than single-aperture reflection coupling. Second, the single-aperture reflection quasi-optical cavity uses a reflection measurement mode, while the dual-aperture through-hole quasi-optical cavity uses a transmission measurement mode. When performing reflection measurements, the dynamic range of a network analyzer is approximately 40 dB due to the directionality of the front-end coupling device. However, when performing transmission measurements, the dynamic range is at least 80 dB. Therefore, a quasi-optical cavity with dual-aperture through-hole coupling is more advantageous for measuring weak resonant signals.

[0003] The dual-aperture through-hole coupled quasi-optical cavity employs a transmission measurement mode. Symmetrical coupling apertures are designed on the top of the spherical mirror, serving as both signal input and output. When using aperture coupling, the resonant signal is relatively weak. Compared to low-frequency network analyzers, the dynamic range signal and noise floor of the 3mm band network analyzer are only slightly different, leading to unstable resonant signals in the quasi-optical cavity dielectric constant measurement system, thus affecting the accuracy and stability of the quality factor measurement. Summary of the Invention

[0004] The purpose of this invention is to provide a calibration method and a dielectric constant measurement method for a quasi-optical cavity dielectric constant measurement system, so as to solve the problems of unstable resonant signal, low accuracy and poor stability of quality factor measurement system in related technologies.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a calibration method for a quasi-optical cavity dielectric constant measurement system, the quasi-optical cavity dielectric constant measurement system comprising a network analyzer and a quasi-optical cavity, the calibration method being implemented based on the network analyzer, wherein during calibration, a transmission frequency response standard to be measured and an isolation standard are sequentially connected to the quasi-optical cavity dielectric constant measurement system, the calibration method comprising:

[0006] Develop frequency response isolation calibration software, which includes transmission frequency response standard software developed for the transmission frequency response standard and isolation standard software developed for the isolation standard;

[0007] When the transmission frequency response standard and the isolation standard are sequentially connected to the quasi-optical cavity dielectric constant measurement system, the transmission frequency response standard software and the isolation standard software are used respectively to perform transmission frequency response calibration and isolation calibration on the quasi-optical cavity dielectric constant measurement system to obtain transmission frequency response error and isolation error.

[0008] The measurement performance error of the quasi-optical cavity dielectric constant measurement system is corrected based on the transmission frequency response error and the isolation error.

[0009] Further, the steps of performing transmission frequency response calibration and isolation calibration on the quasi-optical cavity dielectric constant measurement system using the transmission frequency response standard software and the isolation standard software respectively to obtain the transmission frequency response error and isolation error include:

[0010] The quasi-optical cavity dielectric constant measurement system was calibrated for transmission frequency response, and a first S-parameter relationship including isolation error and transmission frequency response error was obtained. This first S-parameter relationship is obtained using the network analyzer. 21 The parameters are the relationship between the signal parameters measured when calibrating the transmission frequency response of the quasi-optical cavity dielectric constant measurement system.

[0011] The quasi-optical cavity dielectric constant measurement system was isolated and calibrated to obtain a second S-parameter relationship that includes the isolation error. This second S-parameter relationship is obtained using the network analyzer. 21 The parameters are the relationship between the signal parameters measured during the isolation calibration of the quasi-optical cavity dielectric constant measurement system.

[0012] The transmission frequency response error and the isolation error are determined based on the first S-parameter relationship and the second S-parameter relationship.

[0013] Furthermore, before performing transmission frequency response calibration on the quasi-optical cavity dielectric constant measurement system, the method further includes:

[0014] The transmission frequency response standard is connected between the two waveguide ports of the network analyzer. The transmission frequency response standard is a straight transmission line with a length of zero meters and a loss of zero decibels.

[0015] Furthermore, the step of connecting the transmission frequency response standard between the two waveguide ports of the network analyzer includes:

[0016] By directly connecting the two waveguide ports of the network analyzer, the access of the transmission frequency response standard can be realized.

[0017] Furthermore, before performing isolation calibration on the quasi-optical cavity dielectric constant measurement system, the method further includes:

[0018] The isolation standard is connected between the two waveguide ports of the network analyzer.

[0019] Furthermore, the quasi-optical cavity dielectric constant measurement system also includes a signal coupling device, and the step of connecting an isolation standard between the two waveguide ports of the network analyzer includes:

[0020] After connecting the two waveguide ports of the network analyzer to the waveguide ports of the signal coupling device, the isolation standard is set in the quasi-optical cavity.

[0021] Furthermore, when the quasi-optical cavity is an asymmetric quasi-optical cavity, the asymmetric quasi-optical cavity includes a spherical mirror and a plane mirror. The step of connecting the isolation standard between the two waveguide ports of the network analyzer includes:

[0022] After connecting the two waveguide ports of the network analyzer to the waveguide ports of the signal coupling device, the isolation standard is placed on the plane mirror.

[0023] Furthermore, the isolation standard is a fully absorbing sample made of wedge-shaped absorbing material.

[0024] Furthermore, before developing the frequency response isolation calibration software, the method further includes:

[0025] The network analyzer is calibrated using either the short-circuit open-load straight-through (SOLT) calibration method or the short-circuit open-load (SOL) calibration method.

[0026] A second aspect of the present invention also provides a method for measuring dielectric constant, comprising:

[0027] The sample to be tested is placed in a quasi-optical cavity dielectric constant measurement system, and the dielectric constant of the sample to be tested is measured. The quasi-optical cavity dielectric constant measurement system is obtained after calibration by the calibration method of the quasi-optical cavity dielectric constant measurement system.

[0028] Compared with the prior art, the technical solution provided in this application has at least the following technical effects:

[0029] This invention develops calibration software based on a network analyzer, and develops the transmission frequency response standard and isolation standard required for calibration. By measuring the transmission frequency response standard and isolation standard, the system error is corrected, and the calibration of the quasi-optical cavity dielectric constant measurement system based on the network analyzer is realized. This improves the resonant signal of the quasi-optical cavity dielectric constant measurement system, and the measurement accuracy of the quality factor is high, providing a foundation for the accurate calculation of the dielectric constant in the future. Attached Figure Description

[0030] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0031] Figure 1 This is a schematic diagram of the structure of an existing quasi-optical cavity dielectric constant measurement system;

[0032] Figure 2 A flowchart illustrating a calibration method for a quasi-optical cavity dielectric constant measurement system according to an embodiment of the present invention;

[0033] Figure 3 for Figure 2 Detailed implementation flowchart of step S12;

[0034] Figure 4 The connection method of the network analyzer when performing transmission frequency response calibration;

[0035] Figure 5 Flow graph of calibration signal for transmission frequency response standard;

[0036] Figure 6 This describes the connection method for the network analyzer during isolation calibration.

[0037] Figure 7 To calibrate the signal flow graph for isolation standards;

[0038] Figure 8 This is a schematic diagram of a 3mm quasi-optical cavity dielectric constant measurement system.

[0039] Explanation of reference numerals in the attached figures:

[0040] 10. Network analyzer; 101. Waveguide port; 11. Controller; 12. Spread spectrum module; 20. Signal coupling device; 21. Waveguide port; 30. Asymmetric quasi-optical cavity; 31. Spherical mirror; 32. Plane mirror; 40. Platform base; 50. High-precision motion positioning device; 60. Sample under test; 70. Isolation standard. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description and claims. It should be noted that the drawings are all in a very simplified form and are not to a precise scale, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0042] It should be noted that, in order to clearly illustrate the content of this invention, several embodiments are provided to further explain different implementations of the invention. These embodiments are enumerated rather than exhaustive. Furthermore, for the sake of brevity, content mentioned in the preceding embodiments is often omitted in the following embodiments. Therefore, content not mentioned in the later embodiments can be referred to in the preceding embodiments.

[0043] Please see Figure 1 The existing dual-aperture through-hole asymmetric quasi-optical cavity 30 dielectric constant measurement system consists of a network analyzer 10, an asymmetric quasi-optical cavity 30, a signal coupling device 20, a high-precision motion positioning device 50, a cable adapter, and a platform base 40. The dual-aperture through-hole coupled quasi-optical cavity employs a transmission measurement mode. Symmetrical coupling apertures are designed on the top of the spherical mirror 31, serving as both signal input and output. When using aperture coupling, the resonant signal is relatively weak.

[0044] Compared to the low-frequency network analyzer 10, the dynamic range signal and noise floor of the 3mm band network analyzer 10 are only slightly different, resulting in unstable resonant signals and affecting the measurement accuracy and stability of the quality factor. The first embodiment of this invention provides a calibration method for a quasi-optical cavity dielectric constant measurement system. This calibration method can effectively improve the signal-to-noise ratio and measurement accuracy of the quasi-optical cavity dielectric constant measurement system. The quasi-optical cavity measurement system includes a network analyzer 10 and a quasi-optical cavity. In this embodiment, the quasi-optical cavity is an asymmetric quasi-optical cavity 30. The calibration method is based on the network analyzer 10. When calibrating using the network analyzer 10, the transmission frequency response standard to be measured and the isolation standard 70 are sequentially connected to the quasi-optical cavity dielectric constant measurement system, such as... Figure 2 As shown, the calibration method includes the following steps:

[0045] Step S11: Develop frequency response isolation calibration software, which includes transmission frequency response standard software developed for transmission frequency response standards and isolation standard 70 software developed for isolation standard 70.

[0046] Step S12: When the transmission frequency response standard and isolation standard 70 are sequentially connected to the quasi-optical cavity dielectric constant measurement system, the transmission frequency response standard software and isolation standard 70 software are used respectively to perform transmission frequency response calibration and isolation calibration on the quasi-optical cavity dielectric constant measurement system to obtain the transmission frequency response error and isolation error. The transmission frequency response standard is a straight-through transmission line with a length of 0 meters and a loss of 0 dB; that is, the transmission frequency response standard is a virtual calibration standard and not an actual existing standard device.

[0047] Step S13: Correct the measurement performance error of the quasi-optical cavity dielectric constant measurement system based on the transmission frequency response error and isolation error.

[0048] This invention relates to the transmission isolation calibration implementation of a quasi-optical cavity dielectric constant measurement system. First, a transmission frequency response standard and an isolation standard 70 are developed. Then, calibration software corresponding to the calibration standard is written. Finally, the calibration steps are implemented.

[0049] In step S11, the specific steps for developing the frequency response isolation calibration software are as follows:

[0050] 1. Develop frequency response isolation calibration software based on Network Analyzer 10. First, in the software development menu interface of Network Analyzer 10, select Calibration and then CalSet, and create a new calibration model by inserting a new one. Enter the calibration box name (QuasiCal), the calibration box description (Calkit), and the connector type (No Gender).

[0051] 2. Write the standard software 1 - Transmission frequency response standard software: Select the "Thru" standard under "Add Standard", input the minimum and maximum values ​​of the frequency range, the impedance (Z0) is 50Ω by default, the pass-through delay (Delay) is 0ps, and the loss (LOSS) is 0Gohms / s.

[0052] 3. Develop the Standard 2 - Isolation Standard 70 software: Select the [LOAD] standard under [Add Standard], in [Fixed] format, and input the minimum and maximum values ​​of the frequency range. The impedance (Z0) is 50Ω by default, the delay (Delay) is 0ps, and the loss (LOSS) is 0Gohms / s.

[0053] 4. Then select the [Solt] calibration method, add standard software 1 to [FWD TRANS], and add standard software 2 to [Isolation] to complete the calibration software programming.

[0054] Please see Figure 3In step S12, the transmission frequency response standard software and isolation standard 70 software are used respectively to perform transmission frequency response calibration and isolation calibration on the optical cavity dielectric constant measurement system to obtain the transmission frequency response error and isolation error. The steps include the following:

[0055] Step S121: Perform transmission frequency response calibration on the optical cavity dielectric constant measurement system, and measure the first S-parameter relationship including isolation error and transmission frequency response error. The first S-parameter relationship is obtained using the network analyzer 10. 21 The parameters refer to the relationship between signal parameters measured during transmission frequency response calibration of the alignment cavity dielectric constant measurement system. Before performing transmission frequency response calibration on the alignment cavity dielectric constant measurement system, a transmission frequency response standard with a length of zero meters and a loss of zero dB is connected between the two waveguide ports 101 of the network analyzer 10. This can be achieved by directly connecting the two waveguide ports 101 of the network analyzer 10. The specific connection method is as follows... Figure 3 As shown.

[0056] Step S122: Perform isolation calibration on the optical cavity dielectric constant measurement system, and measure the second S-parameter relationship including isolation error. The second S-parameter relationship is obtained using the network analyzer 10. 21 The parameters are the relationship between signal parameters measured during isolation calibration of the optical cavity dielectric constant measurement system.

[0057] Step S123: Determine the transmission frequency response error and isolation error based on the first S-parameter relationship and the second S-parameter relationship.

[0058] Before performing isolation calibration on the quasi-optical cavity dielectric constant measurement system in step S122, an isolation standard 70 is connected between the two waveguide ports 101 of the network analyzer 10. Since the quasi-optical cavity dielectric constant measurement system also includes a signal coupling device 20, the step of connecting the isolation standard 70 between the two waveguide ports 101 of the network analyzer 10 includes: connecting the two waveguide ports 101 of the network analyzer 10 to the waveguide ports 21 of the signal coupling device 20 respectively, and then placing the isolation standard 70 in the quasi-optical cavity. When the quasi-optical cavity is an asymmetric quasi-optical cavity 30, the asymmetric quasi-optical cavity 30 includes a spherical mirror 31 and a plane mirror 32. The step of connecting the isolation standard 70 between the two waveguide ports 101 of the network analyzer 10 includes: connecting the two waveguide ports 101 of the network analyzer 10 to the waveguide ports 21 of the signal coupling device 20 respectively, and then placing the isolation standard 70 on the plane mirror 32, as shown in the figure. Figure 6As shown. Isolation standard 70 is a fully absorbing template made of wedge-shaped absorbing material. The wedge-shaped absorbing material is square, with the side length taken from the diameter of the spherical mirror. The height is selected according to the working frequency band of the asymmetric quasi-optical cavity 30 to ensure that the reflection characteristics of the wedge-shaped absorbing material have a wave absorption performance better than -40dB in the working frequency band of the asymmetric quasi-optical cavity 30.

[0059] Before developing the frequency response isolation calibration software in step S11, the calibration method provided in this embodiment of the invention further includes: calibrating the network analyzer 10 using the Short-Open-Load-Thru (SOLT) calibration method or the Short-Open-Load (SOL) calibration method to further reduce the measurement error of the dielectric constant measurement system. Both the SOLT and SOL calibration methods are based on the 12 error models of the network analyzer 10 for analysis and calibration.

[0060] This invention uses a frequency response and isolation standard 70 to calibrate the dielectric constant measurement system of an asymmetric quasi-optical cavity 30 using a frequency response and isolation calibration method. The frequency response and isolation calibration method ignores the mismatch parameters of port 1 and port 2 of the network analyzer 10: errors in directivity, source matching, reflection frequency response, and load matching, leaving only transmission frequency response error and isolation error. The 12-term error model of the network analyzer 10 can be simplified to a 4-term error model, such as... Figure 5 and Figure 7 Show. Figure 5 Signal flow graph when calibrating the system's access transmission frequency response standard. Figure 7 Signal flow diagram for system access isolation standard 70 calibration.

[0061] According to the signal flow graph Figure 5 The relationship between the actual SA parameters and the measured SM parameters of the device under test (transmission frequency response standard) and the first S parameter is as follows:

[0062]

[0063] In the formula: EX is the forward isolation error, ERX is the reverse isolation error, ETT is the forward transmission frequency response error, and ERT is the reverse transmission frequency response error.

[0064] When the transmission frequency response standard is connected between the two waveguide ports 101 of the network analyzer 10, S 12A =S 21A =1, then the above equation (1) is obtained as:

[0065]

[0066] The above equation (2) is obtained as follows:

[0067]

[0068] When isolation standard 70 is connected between the two waveguide ports 101 of network analyzer 10, S 12A =S 21A =0, obtain the second S-parameter relationship, based on S 12A =S 21A =0, so the above equation (1) is:

[0069] E X =S 21M ……………………………(5).

[0070] The above equation (2) is obtained as follows:

[0071] E RX =S 21M ……………………………(6).

[0072] That is, the second S-parameter relationship is the parameter relationship formed by equations (5) and (6) to obtain only the isolation error. Substituting equations (5) and (6) into equations (3) and (4), we can obtain the forward transmission frequency response error ETT and the reverse transmission frequency response error ERT. Thus, we obtain all four error terms of transmission measurement: forward transmission frequency response error ETT, reverse transmission frequency response error ERT, forward isolation error EX, and reverse isolation error ERX. When measuring the dielectric constant, substituting the calculated system error and the measured values ​​S21M and S12M into equations (1) and (2), we can obtain the true transmission parameters S21A and S12A of the sample under test.

[0073] Please see Figure 4 In this embodiment of the invention, when performing transmission frequency response calibration, according to... Figure 4 Connect the measurement system and select parameter S21 for the network analyzer 10. Disconnect the waveguide port 21 at the front end of the signal coupling device 20 and directly connect the two waveguide ports 101 of the network analyzer 10, as follows: Figure 4 As shown. In the menu interface of Network Analyzer 10, click the Calibration Wizard, select Frequency Response Calibration, and then select the calibration software QuasiCal in View / Select CalKit. In the calibration interface, click THRU to perform transmission frequency response calibration.

[0074] Please see Figure 6After completing the frequency response calibration in this embodiment of the invention, during isolation calibration, the two waveguide ports 101 of the network analyzer 10 are connected to the waveguide port 21 of the signal coupling device 20. The isolation standard 70 is placed on the plane mirror 32. On the calibration interface of the network analyzer 10, click Isolation to perform isolation calibration. After the above steps, the calibration of the quasi-optical cavity dielectric constant measurement system based on the network analyzer 10 is completed. The isolation standard 70 can then be removed, and the dielectric constant of the sample under test can be measured.

[0075] Specifically, to make the present invention clearer, this embodiment of the present invention also uses a 3mm quasi-optical cavity dielectric constant measurement system as an example to illustrate the specific implementation of the calibration method of the quasi-optical cavity dielectric constant measurement system based on the network analyzer 10. Please refer to... Figure 8 A 3mm network analyzer system (N5225B), controller (N5261A), and 3mm spread spectrum module (V10VNA2-T / R-N5260A) from a certain company were used to construct the 3mm network analyzer system. A 3mm quasi-optical cavity dielectric constant measurement system was constructed using a self-developed asymmetric 3mm quasi-optical cavity, 3mm signal coupling device 20, and 3mm waveguide section (i.e., waveguide port 101). Figure 7 As shown. The 3mm network analyzer 10 was set to a frequency of 75GHz to 110GHz, with measurement parameters S21, 16001 points, 8 average times, and 100Hz intermediate frequency bandwidth.

[0076] The minimum frequency range is 59.01 GHz, and the maximum frequency range is 118 GHz. The calibration software QuasiCal3 was developed. The transmission frequency response standard for the 3mm band is 0 meters and 0 dB transmission line. The isolation standard 70 is a 300mm×300mm×50mm wedge-shaped absorbing material.

[0077] First of all Figure 4 The two waveguide ports 101 shown are directly connected to complete the frequency response calibration. Then press... Figure 6 Connect the two waveguide ports 101 to the two waveguide ports 21 of the signal coupling device 20 respectively, and place the isolation standard 70 on the quasi-optical cavity plane mirror 32 to complete the isolation calibration.

[0078] After calibration using the transmission-isolation method, the signal-to-noise ratio of the quasi-optical cavity dielectric constant measurement system was significantly improved. This facilitates the accurate acquisition of the measurement resonant frequency and quality factor, providing a foundation for the accurate calculation of the dielectric constant.

[0079] Table 1 shows the quality factor measurement results of the quasi-optical cavity dielectric constant measurement system before and after calibration. It can be clearly seen that after transmission frequency response isolation calibration, the quality factor of the quasi-optical cavity dielectric constant measurement system is significantly improved without changing parameters such as cavity length.

[0080]

[0081] Table 1 Comparison of Quality Factors

[0082] This invention develops calibration software based on a network analyzer 10, and develops the required transmission frequency response standard and isolation standard 70 for calibration. By measuring the transmission frequency response standard and isolation standard 70, the system error is corrected, and the calibration of the quasi-optical cavity dielectric constant measurement system based on the network analyzer 10 is realized. This improves the resonant signal of the quasi-optical cavity dielectric constant measurement system, and the measurement accuracy of the quality factor is high, providing a foundation for the accurate calculation of the dielectric constant in the future.

[0083] The second embodiment of the present invention also provides a method for measuring dielectric constant, which includes: placing the sample to be tested into a quasi-optical cavity dielectric constant measuring system and measuring the dielectric constant of the sample to be tested. The quasi-optical cavity dielectric constant measuring system is obtained by calibrating the quasi-optical cavity dielectric constant measuring system provided in the first embodiment of the present invention. For the calibration method of the quasi-optical cavity dielectric constant measuring system, please refer to the content provided in the first embodiment of the present invention. The embodiments of the present invention will not be described again here.

[0084] The dielectric constant measurement method proposed in this invention can improve the measurement accuracy of the dielectric constant of the sample under test.

[0085] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A calibration method for a quasi-optical cavity dielectric constant measurement system, characterized in that, The quasi-optical cavity dielectric constant measurement system comprises a network analyzer (10) and a quasi-optical cavity, the calibration method is realized based on the network analyzer (10), when calibrating, a transmission frequency response standard and an isolation standard (70) to be measured are sequentially connected in the quasi-optical cavity dielectric constant measurement system, and the calibration method comprises the following steps: Frequency response isolation calibration software is programmed, the frequency response isolation calibration software comprises transmission frequency response standard software programmed for the transmission frequency response standard, and isolation standard software programmed for the isolation standard (70); When the transmission frequency response standard and the isolation standard (70) are sequentially connected in the quasi-optical cavity dielectric constant measurement system, the transmission frequency response standard software and the isolation standard software are respectively used to calibrate the transmission frequency response and the isolation of the quasi-optical cavity dielectric constant measurement system, so as to obtain transmission frequency response errors and isolation errors; According to the transmission frequency response errors and the isolation errors, the measurement performance errors of the quasi-optical cavity dielectric constant measurement system are corrected.

2. The method of calibrating a quasi-optical cavity permittivity measurement system of claim 1, wherein, The steps of respectively using the transmission frequency response standard software and the isolation standard software to calibrate the transmission frequency response and the isolation of the quasi-optical cavity dielectric constant measurement system to obtain transmission frequency response errors and isolation errors comprise the following steps: The transmission frequency response of the quasi-optical cavity dielectric constant measurement system is calibrated, and a first S parameter relationship containing isolation errors and transmission frequency response errors is measured, the first S parameter relationship is an S21 parameter of the network analyzer (10), and a signal parameter relationship measured when the transmission frequency response of the quasi-optical cavity dielectric constant measurement system is calibrated; The quasi-optical cavity permittivity measurement system is isolated calibrated to measure a second S parameter relationship containing an isolation error, the second S parameter relationship being an S parameter relationship measured using the network analyzer (10) 21 parameter of the quasi-optical cavity permittivity measurement system when isolated calibrated, the signal parameter relationship measured when the quasi-optical cavity permittivity measurement system is isolated calibrated; According to the first S parameter relationship and the second S parameter relationship, the transmission frequency response errors and the isolation errors are determined.

3. The method of calibrating a quasi-optical cavity permittivity measurement system of claim 1, wherein, Before the transmission frequency response of the quasi-optical cavity dielectric constant measurement system is calibrated, the method further comprises the following steps: The transmission frequency response standard is connected between two waveguide ports (101) of the network analyzer (10), and the transmission frequency response standard is a straight-through transmission line with a length of zero meters and a loss of zero decibels.

4. The method of calibrating a quasi-optical cavity permittivity measurement system of claim 3, wherein, The step of connecting the transmission frequency response standard between the two waveguide ports (101) of the network analyzer (10) comprises the following steps: The two waveguide ports (101) of the network analyzer (10) are directly connected, and the transmission frequency response standard is connected.

5. The method of calibrating a quasi-optical cavity permittivity measurement system of claim 1, wherein, Before the isolation of the quasi-optical cavity dielectric constant measurement system is calibrated, the method further comprises the following steps: The isolation standard (70) is connected between the two waveguide ports (101) of the network analyzer (10).

6. The method of calibrating a quasi-optical cavity permittivity measurement system of claim 5, wherein, The quasi-optical cavity dielectric constant measurement system further comprises a signal coupling device (20), and the step of connecting the isolation standard (70) between the two waveguide ports (101) of the network analyzer (10) comprises the following steps: After the two waveguide ports (101) of the network analyzer (10) are connected with waveguide ports (21) of the signal coupling device (20) respectively, the isolation standard (70) is arranged in the quasi-optical cavity.

7. The method of calibrating a quasi-optical cavity permittivity measurement system of claim 6, wherein, When the quasi-optical cavity is an asymmetric quasi-optical cavity (30), the asymmetric quasi-optical cavity (30) comprises a spherical mirror (31) and a plane mirror (32), and the step of inserting the isolation standard (70) between the two waveguide ports (101) of the network analyzer (10) comprises: After connecting the two waveguide ports (101) of the network analyzer (10) to the waveguide ports (21) of the signal coupling device (20) respectively, the isolation standard (70) is placed on the plane mirror (32).

8. A method of calibrating a quasi-optical cavity permittivity measurement system as claimed in any one of claims 5 to 7, wherein, The isolation standard (70) is a full absorption sample plate made of a sharp wedge type wave absorbing material.

9. The method of calibrating a quasi-optical cavity permittivity measurement system of claim 1, wherein, Before compiling the frequency response isolation calibration software, the method further comprises: The network analyzer (10) is calibrated by using a short-circuit open-circuit load straight-through SOLT calibration method, or the network analyzer (10) is calibrated by using a short-circuit open-circuit load SOL calibration method.

10. A method of measuring the dielectric constant, characterized by, Comprise: The dielectric constant of the sample to be measured is measured by placing the sample to be measured into the quasi-optical cavity dielectric constant measurement system, wherein the quasi-optical cavity dielectric constant measurement system is calibrated by the calibration method of the quasi-optical cavity dielectric constant measurement system according to any one of claims 1 to 9.

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