System and method for measuring line loss of radio frequency coaxial cable

Abstract

The invention relates to a system and method for measuring the line loss of a radio frequency coaxial cable, and the system comprises a signal generation module which is used for transmitting a CW signal; the port compensation module is used for receiving the CW signal, connecting the reference radio frequency cable with the two ports of the comprehensive tester, acquiring the line loss compensation amount of the two ports, and updating the compensation coefficient of the two ports in the configuration file of the two ports of the comprehensive tester based on the line loss compensation amount; the clamp line loss value acquisition module is used for receiving the CW signal and connecting the reference radio frequency cable with the multi-joint conversion clamp through the two ports after the compensation coefficients are updated so as to acquire the line loss value of the multi-joint conversion clamp; and the to-be-measured line loss acquisition module is used for receiving the CW signal, connecting the to-be-measured radio frequency cable with the reference radio frequency cable by using the multi-joint conversion clamp through the two ports after the compensation coefficients are updated, acquiring an overall line loss value, and acquiring the line loss value of the to-be-measured radio frequency cable based on the overall line loss value and the line loss value of the multi-joint conversion clamp.

Description

Technical Field

[0001] The present invention relates to the field of radio frequency communication technology, and in particular to a system and method for measuring radio frequency coaxial cable line loss. Background Art

[0002] In the field of radio frequency engineering, coaxial cables and their matching connectors are often used to connect various functional blocks, devices or oscillator units (i.e., feed power). The radio frequency coaxial cable consists of an inner conductor, a dielectric, an outer conductor and a sheath, such as Figure 1 In modern communication systems, RF coaxial cables are usually used to transmit RF and microwave signal energy. However, due to the "skin effect" and energy conversion of RF energy transmission, there are dielectric loss, conductor loss and radiation loss in the signal transmission process. Any signal transmission loss will directly affect the performance of the communication system. In actual engineering applications, this loss value needs to be compensated. Therefore, the measurement accuracy of RF coaxial cable transmission loss is crucial.

[0003] For a coaxial cable assembly, its total transmission loss is the insertion loss of the assembly, which includes cable loss, connector loss and mismatch loss and can be expressed by formula (1).

[0004] L insert =L cable +L connector +L mismatch (1)

[0005] The cable loss depends on the cable length, frequency and loss coefficient, and the calculation process is relatively complicated. In engineering, a simplified empirical algorithm is usually used:

[0006]

[0007] Among them, L0 is the loss value of the 100-foot long RF cable (in dB / 100ft), k1 is the resistance loss coefficient, k2 is the dielectric loss coefficient, and f is the frequency (in MHz). Therefore, the final cable loss is the product of L0 and the cable length.

[0008] The connector loss depends on the connector loss factor and frequency. The connector can be straight-through or right-angle. The connector loss calculation formula is as follows:

[0009]

[0010] Where CLF is the connector loss factor, which is usually 0.12 (straight-through), 0.21 (straight-through-right angle) and 0.3 (right angle-right angle), and is selected according to the type of connectors at both ends of the connector; F is the frequency (in GHz).

[0011] Mismatch loss is caused by nonlinear factors inside the coaxial cable and the mismatch of characteristic impedance, and cannot be calculated using theoretical or empirical formulas.

[0012] Since the actual loss level does not depend linearly on the frequency used, the cable loss is usually measured at a given frequency. There are two existing methods for measuring RF cable line loss: network analyzer measurement or signal source and spectrum analyzer combined measurement, including: (1) Network analyzer line loss measurement process for RF cable: connect the two ends of the RF cable to port 1 and port 2 of the network analyzer respectively, and then select the appropriate test mode (S 11 Mode or S 21 (2) The signal source and spectrum analyzer combined measurement method is to set the test frequency f0 and a certain output power level value P1 on the signal source, and read the frequency level P2 on the spectrum analyzer after passing through the cable. The loss P2 of the cable at the frequency f0 is then L =P1-P2.

[0013] However, these two methods have certain limitations in terms of accuracy, operational complexity and cost. Therefore, there is an urgent need for a low-cost, accurate and easy-to-operate line loss measurement method.

[0014] The calibration process before testing in the above method (1) is complex and costly. The network analyzer measurement instrument is characterized by the parameters between ports, and all measurement results are ratio operations between receivers. Calibration is to ensure that the ratios between receivers can be accurately converted into parameters between ports. Engineering practice has shown that calibration can greatly improve the measurement accuracy of network analyzers, and only accurately calibrated network analyzers are precision measuring instruments. The calibration methods of network analyzers are divided into many types according to the different devices under test, such as SOLT, LRL (TRL), LRM, SSST, etc. Most methods require corresponding calibration standards and are greatly affected by the calibration standards.

[0015] The test system of the above method (2) is not convenient to move, and because the internal reference frequency of the signal source and the spectrum analyzer are not synchronized, a large system error will be introduced, resulting in low accuracy of the test results. Summary of the invention

[0016] In order to solve the above problems existing in the prior art, the purpose of the present invention is to provide a system and method for measuring radio frequency coaxial cable line loss, which is suitable for performance testing of wireless communications, radio frequency components and equipment.

[0017] To achieve the above object, the present invention provides the following solutions:

[0018] A system for measuring line loss of a radio frequency coaxial cable, comprising:

[0019] A signal generating module, used for transmitting a CW signal;

[0020] A port compensation module is used to receive the CW signal, connect the reference RF cable to the two ports of the comprehensive tester, obtain the line loss compensation amount of the two ports, and update the compensation coefficients of the two ports in the configuration files of the two ports of the comprehensive tester based on the line loss compensation amount;

[0021] A fixture line loss value acquisition module is used to receive the CW signal and connect the reference RF cable to the multi-connector conversion fixture through two ports after updating the compensation coefficient to obtain the line loss value of the multi-connector conversion fixture;

[0022] A line loss acquisition module to be tested, used to receive the CW signal, and connect the RF cable to be tested with the reference RF cable by using the multi-connector conversion fixture through two ports after updating the compensation coefficient, to obtain an overall line loss value, and based on the overall line loss value and the line loss value of the multi-connector conversion fixture, to obtain the line loss value of the RF cable to be tested;

[0023] Wherein, the signal generating module is respectively connected with the port compensation module, the fixture line loss value acquiring module and the line loss to be measured acquiring module.

[0024] Optionally, the port compensation module includes:

[0025] A compensation amount acquisition submodule is used to receive the CW signal, connect the reference RF cable to the two ports of the comprehensive tester, obtain the actual measured power through the power measurement device of the comprehensive tester, and simultaneously obtain the actual transmission power of the signal generation module, and obtain the line loss compensation amount of the two ports of the comprehensive tester based on the actual measured power and the actual transmission power;

[0026] The port compensation submodule is used to update the compensation coefficients of the two ports in the configuration files of the two ports of the comprehensive tester based on the line loss compensation amount.

[0027] Optionally, the port compensation submodule includes:

[0028] A port compensation unit is used to obtain the original line loss compensation values ​​of the two ports in the configuration file of the two ports of the comprehensive tester, obtain the line loss compensation value according to the line loss compensation amount and a preset compensation coefficient, calculate the sum of the line loss compensation value and the original line loss compensation value, obtain the calibrated line loss compensation value, and update the compensation coefficients of the two ports in the configuration file of the two ports of the comprehensive tester according to the calibrated line loss compensation value combined with the original line loss compensation value.

[0029] Optionally, the line loss compensation amounts of the two ports include: a line loss value of the reference RF cable and a line loss value of the two ports.

[0030] Optionally, a method for obtaining the line loss compensation amounts of the two ports is:

[0031]

[0032] Wherein, A is the line loss compensation amount of the two ports, B2 is the first power of the CW signal transmitted when acquiring the line loss to be measured, B1 is the second power of the CW signal transmitted when updating the compensation coefficients of the two ports in the configuration files of the two ports of the comprehensive tester, C k is the first power received by the power measuring device when the compensation coefficients of the two ports in the configuration files of the two ports of the comprehensive tester are updated, C fx is the second power received by the power measurement device when acquiring the line loss to be measured, and K is the compensation coefficient of the two ports in the updated configuration file of the two ports of the comprehensive tester.

[0033] Optionally, the multi-connector conversion fixture switches the radio frequency N connector and the first SMA connector, the second SMA connector, the first N connector, and the second N connector through a single-pole four-throw radio frequency switch.

[0034] Optionally, the method for obtaining the line loss value of the radio frequency cable to be tested is:

[0035] F = DE;

[0036] Among them, F is the line loss value of the RF cable to be tested, D is the overall line loss value, and E is the line loss value of the multi-connector conversion fixture.

[0037] Optionally, the system further includes: a line loss display module, used to display the line loss value of the radio frequency cable to be tested.

[0038] To achieve the above object, the present invention also provides a method for measuring line loss of a radio frequency coaxial cable, comprising:

[0039] Transmit CW signal;

[0040] Receive the CW signal, connect the reference RF cable to the two ports of the comprehensive tester, obtain the line loss compensation amount of the two ports, and update the compensation coefficients of the two ports in the configuration files of the two ports of the comprehensive tester based on the line loss compensation amount;

[0041] Receive the CW signal, and connect the reference RF cable to the multi-connector conversion fixture through the two ports after updating the compensation coefficient, to obtain the line loss value of the multi-connector conversion fixture;

[0042] The CW signal is received, and the RF cable to be tested is connected to the reference RF cable using the multi-connector conversion fixture through the two ports after updating the compensation coefficient, so as to obtain the overall line loss value, and the line loss value of the RF cable to be tested is obtained based on the overall line loss value and the line loss value of the multi-connector conversion fixture.

[0043] The beneficial effects of the present invention are:

[0044] The present invention aims to provide a method and system for measuring radio frequency cable loss in the field and in the laboratory, which is suitable for the detection and measurement field. The test system is composed of a comprehensive tester, a reference radio frequency cable, a radio frequency cable to be tested, a multi-connector conversion fixture and a computer. The present invention utilizes the insertion loss principle to connect the reference radio frequency cable with the two ports of the comprehensive tester, obtain the line loss compensation amount of the two ports, update the compensation coefficients of the two ports in the configuration files of the two ports of the comprehensive tester, further measure the line loss of the radio frequency cable, and realize multi-connector compatibility testing by designing a multi-connector conversion fixture. Finally, the computer technology is combined to realize the automatic testing.

[0045] The present invention can not only measure the RF cable loss with a single comprehensive tester, but also realize multi-frequency point automatic testing through a program. From the perspective of application scenarios, it is convenient to carry and suitable for on-site acceptance tests, etc. From the perspective of testing technology, this method can solve the problem of poor measurement accuracy caused by reasons such as internal loss of the instrument and small line loss value of short RF cables. From the perspective of use cost, this method is low-cost and easy to operate.

[0046] The present invention is simple and easy to operate, low in cost and convenient to move, suitable for various field and laboratory environments, and can flexibly respond to different needs. In addition, the measurement result of the present invention has high accuracy, uses standard load and zero point calibration to ensure high accuracy of the measurement result, and has strong operability and traceability, and is very suitable for application in the fields of detection and measurement.

[0047] The RF line loss measurement method proposed in the present invention can realize automated testing through simple commands, meet the requirements of repeatable testing, and improve testing efficiency. At the same time, it also eliminates measurement errors introduced by the tester's skill level and experience and poor connector contact. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments 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.

[0049] Figure 1 A schematic diagram of the structure of a radio frequency coaxial cable of the background technology of the present invention;

[0050] Figure 2 A schematic diagram of a system for measuring line loss of a radio frequency coaxial cable according to an embodiment of the present invention. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0053] The comprehensive tester, full name of wireless communication comprehensive tester, is mainly used for testing analog or digital mobile communication base stations / mobile phones, and is also widely used in RF signal performance related testing of Bluetooth and WLAN products. At the same time, the comprehensive tester also has some functions of signal generator (VSG) and signal analyzer (VSA), which can test both the transmission performance and the receiving performance of the product.

[0054] The basic principle of the comprehensive tester: Signal simulation: The comprehensive tester generates various simulated communication signals through the internal signal source, including RF signals of different frequencies, amplitudes and modulation methods. These signals are used to test the receiving and transmitting performance of the device to ensure the performance of the device under different network conditions. Signal reception and analysis: When the device transmits signals, the comprehensive tester receives these signals and performs detailed analysis, including signal power, frequency, spectrum, modulation quality and other parameters. Through the high-performance spectrum analyzer, the comprehensive tester can accurately measure various parameters of the signal and evaluate the RF performance of the device.

[0055] Application scenarios of comprehensive testers: Comprehensive testers are widely used in the design and development of wireless communication equipment, performance calibration and testing during the production process. Specific application scenarios include: Product design and development: During the product development stage, comprehensive testers are used to verify the RF performance of the equipment to ensure that it meets the design requirements. Production testing: During the production process, comprehensive testers are used to calibrate and test the RF performance of the equipment to ensure product quality in large-scale production.

[0056] It should be noted that the following implementation is also applicable to other measuring devices, and the following only uses the comprehensive measuring instrument as an example to illustrate the measurement method:

[0057] At the standard station, the mobile terminal is connected to the standard comprehensive tester through a standard RF cable; at the calibration station, the mobile terminal is connected to the calibration comprehensive tester through a calibration RF cable. At the standard station, the transmission line loss compensation value T of the standard RF cable is accurately measured. In this embodiment, the transmission line loss compensation value P of the calibration RF cable at the production line calibration station is calculated based on the transmission line loss compensation value T of the standard RF cable. 发 An embodiment of a transmission line loss measurement method includes the following steps:

[0058] Step 101: At the standard station, control the mobile terminal to transmit a signal with a preset DAC value, the mobile terminal is connected to the standard comprehensive tester through the standard RF cable of the standard station, and the signal transmission power P1 measured by the standard comprehensive tester is read, and the transmission line loss compensation value of the standard RF cable is T; Step 102: At the calibration station, control the mobile terminal to transmit a signal with a preset DAC value, the mobile terminal is connected to the calibration comprehensive tester through the calibration RF cable of the calibration station, and the signal transmission power P2 measured by the calibration comprehensive tester is read; Step 103: Calculate the transmission line loss compensation value P of the calibration RF cable 发 , P 发 =T plus the difference between P1 and P2. In the specific implementation, when using the same mobile terminal and transmitting the signal with the same digital to analog converter (DAC) value, respectively read the signal transmission power P1 measured at the standard station and the signal transmission power P2 measured at the calibration station. If the transmission line loss of the calibration RF cable is the same as that of the standard RF cable (that is, the transmission line loss compensation values ​​of the two are the same), the values ​​of P1 and P2 read should be the same; if the transmission line loss of the calibration RF cable is different from that of the standard RF cable, the difference between P1 and P2 is the transmission line loss compensation value P of the calibration RF cable. 发 The difference between the transmission line loss compensation value T of the standard RF cable, that is, P1-P2=P 发 -T, then P 发 =T+(P1-P2).

[0059] In order to make the test results more accurate, multiple DAC values ​​can be pre-set to test the signal transmission power corresponding to the standard position of each DAC value and the signal transmission power corresponding to the calibration position of each DAC value. The transmission line loss compensation value P of the calibration RF cable is 发 =T plus the average value of the difference between the signal transmission power of each preset DAC value at the standard position and the signal transmission power at the calibration position. Then P 发=T+Δ1.

[0060] Further, after obtaining the transmission line loss compensation value P of the calibration RF cable, 发 Afterwards, you can also confirm P 发 Whether it is accurate, the specific confirmation steps can be as follows: Step 201, control the calibration comprehensive tester to use the transmission line loss compensation value P 发 The transmission line loss of the calibration radio frequency cable is compensated; specifically, the transmission line loss compensation value P 发 Write the calibration tester, and control the calibration tester through software programming to call the transmission line loss compensation value P during measurement. 发 Compensate for the transmission line loss. Step 202, at the calibration station, control the mobile terminal to transmit the signal of the preset DAC value again, and read the signal transmission power P3 measured by the calibration comprehensive tester; Step 203, determine whether the difference between P3 and P1 is less than the preset line loss value. If not, it means that the error of the transmission line loss compensation value of the calibration RF cable is large and unacceptable, then execute step 204; if less than, it means that the error of the transmission line loss compensation value of the calibration RF cable is small and within an acceptable range, then end the processing; the preset line loss value can be set according to the actual accuracy requirements. Step 204, adjust the transmission line loss compensation value P according to the preset fine-tuning step. 发 , until the difference between P3 and P1 is less than the preset line loss value. The preset fine-tuning step size may be + / -1dB or + / -2dB, etc.

[0061] In this embodiment, the transmission line loss compensation value of the standard RF cable can be obtained in advance in the laboratory, and the transmission line loss compensation value of the calibrated RF cable at the production line calibration station can be calculated based on the transmission line loss compensation value of the standard RF cable. The entire testing process only requires the mobile terminal with precise power to be tested once at the standard station and the calibration station respectively, so as to accurately know the transmission line loss compensation value of the calibrated RF cable, and the entire testing process can be controlled by software design, thus saving time and effort and improving testing efficiency.

[0062] like Figure 2As shown, this embodiment discloses a system for measuring line loss of an RF coaxial cable, comprising: a signal generating module for transmitting a CW signal; a port compensation module for receiving the CW signal, connecting a reference RF cable to two ports of a comprehensive tester, obtaining line loss compensation amounts of the two ports, and updating compensation coefficients of the two ports in a configuration file of the two ports of the comprehensive tester based on the line loss compensation amounts; a fixture line loss value acquisition module for receiving the CW signal, and connecting the reference RF cable to a multi-connector conversion fixture through the two ports after updating the compensation coefficients, and obtaining line loss values ​​of the multi-connector conversion fixture; a line loss acquisition module to be measured, for receiving the CW signal, and connecting the RF cable to be measured to the reference RF cable using the multi-connector conversion fixture through the two ports after updating the compensation coefficients, and obtaining an overall line loss value, and obtaining a line loss value of the RF cable to be measured based on the overall line loss value and the line loss value of the multi-connector conversion fixture; wherein the signal generating module is connected to the port compensation module, the fixture line loss value acquisition module, and the line loss acquisition module to be measured, respectively.

[0063] Furthermore, the port compensation module includes: a compensation amount acquisition submodule, which is used to receive the CW signal, connect the reference RF cable to the two ports of the comprehensive tester, obtain the actual measured power through the power measurement device of the comprehensive tester, and simultaneously obtain the actual transmission power of the signal generating module, and obtain the line loss compensation amount of the two ports of the comprehensive tester based on the actual measured power and the actual transmission power; a port compensation submodule, which is used to update the compensation coefficients of the two ports in the configuration files of the two ports of the comprehensive tester based on the line loss compensation amount.

[0064] Furthermore, the port compensation submodule includes: a port compensation unit, used to obtain the original line loss compensation values ​​of the two ports in the configuration file of the two ports of the comprehensive tester, obtain the line loss compensation value according to the line loss compensation amount and a preset compensation coefficient, calculate the sum of the line loss compensation value and the original line loss compensation value, obtain the calibrated line loss compensation value, and update the compensation coefficients of the two ports in the configuration file of the two ports of the comprehensive tester according to the calibrated line loss compensation value combined with the original line loss compensation value.

[0065] Furthermore, the line loss compensation amounts of the two ports include: a line loss value of the reference RF cable and a line loss value of the two ports.

[0066] Furthermore, the method for obtaining the line loss compensation amount of the two ports is:

[0067]

[0068] Wherein, A is the line loss compensation amount of the two ports, B2 is the first power of the CW signal transmitted when acquiring the line loss to be measured, B1 is the second power of the CW signal transmitted when updating the compensation coefficients of the two ports in the configuration files of the two ports of the comprehensive tester, C k is the first power received by the power measuring device when the compensation coefficients of the two ports in the configuration files of the two ports of the comprehensive tester are updated, C fx is the second power received by the power measurement device when acquiring the line loss to be measured, and K is the compensation coefficient of the two ports in the updated configuration file of the two ports of the comprehensive tester.

[0069] Furthermore, the multi-connector conversion fixture switches the radio frequency N connector with the first SMA connector, the second SMA connector, the first N connector, and the second N connector through a single-pole four-throw radio frequency switch.

[0070] Specifically, the switching between the RF N (male) connector and SMA (male), SMA (female), N (male), and N (female) is achieved through a single-pole four-throw RF switch, such as Figure 2 The multi-connector conversion fixture can match the instrument interface with the connector under test, which is not only compatible with a variety of RF cable connectors, but also improves measurement accuracy.

[0071] Furthermore, the method for obtaining the line loss value of the radio frequency cable to be tested is:

[0072] F = DE;

[0073] Among them, F is the line loss value of the RF cable to be tested, D is the overall line loss value, and E is the line loss value of the multi-connector conversion fixture.

[0074] Furthermore, the system also includes: a line loss display module, which is used to display the line loss value of the radio frequency cable to be tested.

[0075] The device for realizing the above system includes: a comprehensive tester, a reference RF cable, a tested RF cable, a multi-connector conversion fixture and a computer. The test environment of the device should avoid co-frequency or adjacent frequency interference, and the frequency, power setting and measurement can be automatically tested through simple instructions. The line loss values ​​at multiple frequency points can be quickly calibrated, thereby improving test efficiency and operation convenience.

[0076] It has the CW signal transmission function of a signal generator, and its power measurement module can perform power measurement. After setting a specific frequency and power level value (the default setting is 0), the CW signal is transmitted to the power measurement module through the RF cable, and the power value in the display area is the RF cable loss value at a given frequency.

[0077] After the reference cable is introduced, the loss value of the cable under test can be tested through the insertion loss measurement principle to improve the test accuracy of the system. It is suitable for insertion loss testing of shorter RF coaxial cable assemblies to meet application scenarios with high insertion loss requirements such as microwave communications and satellite communications. The insertion loss measurement steps in the present invention are: first measure the line loss value PL1 of the reference RF cable and the multi-connector conversion fixture; then connect the RF cable under test with the reference RF cable using a multi-connector conversion fixture, and measure the overall line loss value PL2. The difference between the two line loss measurements is the loss of the cable under test PL0 = PL1-PL2.

[0078] The present embodiment also discloses a method for measuring line loss of an RF coaxial cable, comprising: transmitting a CW signal, receiving the CW signal, connecting a reference RF cable to two ports of a comprehensive tester, obtaining line loss compensation amounts of the two ports, and updating the compensation coefficients of the two ports in a configuration file of the two ports of the comprehensive tester based on the line loss compensation amounts; receiving the CW signal, and connecting the reference RF cable to a multi-connector conversion fixture through the two ports after updating the compensation coefficients, and obtaining a line loss value of the multi-connector conversion fixture; receiving the CW signal, and connecting the RF cable to be tested to the reference RF cable using the multi-connector conversion fixture through the two ports after updating the compensation coefficients, and obtaining an overall line loss value, and obtaining the line loss value of the RF cable to be tested based on the overall line loss value and the line loss value of the multi-connector conversion fixture.

[0079] All devices in this embodiment can be measured and traced, ensuring the accuracy of the measurement results. In addition, the RF cable line loss measurement provided in this embodiment can be completed with only one comprehensive tester, and the test is simple and easy to operate.

[0080] In the field of detection and measurement, many items of testing are completed by comprehensive testers. Therefore, applying this embodiment to measure line loss can offset the internal loss of the comprehensive tester, thereby improving the accuracy of detection and measurement.

[0081] This embodiment proposes using a single-pole four-throw RF switch to implement a multi-connector conversion fixture, which can be used in situations where the RF cable under test does not match the interface of the comprehensive tester, improves test accuracy, has a wider test range, and is more flexible in operation. It is more suitable for insertion loss testing of shorter RF coaxial cable assemblies and meets application scenarios such as microwave communications and satellite communications that have high requirements for insertion loss.

[0082] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A system for measuring line loss of radio frequency coaxial cable, characterized in that: include: A signal generating module, used for transmitting a CW signal; A port compensation module is used to receive the CW signal, connect the reference RF cable to the two ports of the comprehensive tester, obtain the line loss compensation amount of the two ports, and update the compensation coefficients of the two ports in the configuration files of the two ports of the comprehensive tester based on the line loss compensation amount; A fixture line loss value acquisition module is used to receive the CW signal and connect the reference RF cable to the multi-connector conversion fixture through two ports after updating the compensation coefficient to obtain the line loss value of the multi-connector conversion fixture; A line loss acquisition module to be tested, used to receive the CW signal, and connect the RF cable to be tested with the reference RF cable by using the multi-connector conversion fixture through two ports after updating the compensation coefficient, to obtain an overall line loss value, and based on the overall line loss value and the line loss value of the multi-connector conversion fixture, to obtain the line loss value of the RF cable to be tested; Wherein, the signal generating module is respectively connected with the port compensation module, the fixture line loss value acquiring module and the line loss to be measured acquiring module.

2. The system for measuring line loss of radio frequency coaxial cable according to claim 1, characterized in that: The port compensation module comprises: A compensation amount acquisition submodule is used to receive the CW signal, connect the reference RF cable to the two ports of the comprehensive tester, obtain the actual measured power through the power measurement device of the comprehensive tester, and simultaneously obtain the actual transmission power of the signal generation module, and obtain the line loss compensation amount of the two ports of the comprehensive tester based on the actual measured power and the actual transmission power; The port compensation submodule is used to update the compensation coefficients of the two ports in the configuration files of the two ports of the comprehensive tester based on the line loss compensation amount.

3. The system for measuring line loss of radio frequency coaxial cable according to claim 2, characterized in that: The port compensation submodule comprises: A port compensation unit is used to obtain the original line loss compensation values ​​of the two ports in the configuration file of the two ports of the comprehensive tester, obtain the line loss compensation value according to the line loss compensation amount and a preset compensation coefficient, calculate the sum of the line loss compensation value and the original line loss compensation value, obtain the calibrated line loss compensation value, and update the compensation coefficients of the two ports in the configuration file of the two ports of the comprehensive tester according to the calibrated line loss compensation value combined with the original line loss compensation value.

4. The system for measuring line loss of radio frequency coaxial cable according to claim 1, characterized in that: The line loss compensation amounts of the two ports include: the line loss value of the reference RF cable and the line loss values ​​of the two ports.

5. The system for measuring line loss of radio frequency coaxial cable according to claim 1, characterized in that: The method for obtaining the line loss compensation amount of the two ports is: Wherein, A is the line loss compensation amount of the two ports, B2 is the first power of the CW signal transmitted when acquiring the line loss to be measured, B1 is the second power of the CW signal transmitted when updating the compensation coefficients of the two ports in the configuration files of the two ports of the comprehensive tester, C k is the first power received by the power measuring device when the compensation coefficients of the two ports in the configuration files of the two ports of the comprehensive tester are updated, C fx is the second power received by the power measurement device when acquiring the line loss to be measured, and K is the compensation coefficient of the two ports in the updated configuration file of the two ports of the comprehensive tester.

6. The system for measuring line loss of radio frequency coaxial cable according to claim 1, characterized in that: The multi-connector conversion fixture switches the radio frequency N connector with the first SMA connector, the second SMA connector, the first N connector, and the second N connector through a single-pole four-throw radio frequency switch.

7. The system for measuring line loss of radio frequency coaxial cable according to claim 1, characterized in that: The method for obtaining the line loss value of the radio frequency cable to be tested is: F = DE; Among them, F is the line loss value of the RF cable to be tested, D is the overall line loss value, and E is the line loss value of the multi-connector conversion fixture.

8. The system for measuring line loss of radio frequency coaxial cable according to claim 1, characterized in that: The system also includes: a line loss display module, which is used to display the line loss value of the radio frequency cable to be tested.

9. A method for measuring line loss of a radio frequency coaxial cable, characterized in that: include: Transmit CW signal; Receive the CW signal, connect the reference RF cable to the two ports of the comprehensive tester, obtain the line loss compensation amount of the two ports, and update the compensation coefficients of the two ports in the configuration files of the two ports of the comprehensive tester based on the line loss compensation amount; Receive the CW signal, and connect the reference RF cable to the multi-connector conversion fixture through the two ports after updating the compensation coefficient, to obtain the line loss value of the multi-connector conversion fixture; The CW signal is received, and the RF cable to be tested is connected to the reference RF cable using the multi-connector conversion fixture through the two ports after updating the compensation coefficient, so as to obtain the overall line loss value, and the line loss value of the RF cable to be tested is obtained based on the overall line loss value and the line loss value of the multi-connector conversion fixture.

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