A dynamic intermodulation test apparatus and method

Abstract

The application discloses a kind of dynamic intermodulation test devices, the device includes: driving gear, passive gear, waltz gear, support, motor and control instrument;The driving gear drives waltz gear to rotate, the passive gear is cooperated with driving gear, to tighten waltz gear;The waltz gear is used to fix cable assembly, so that cable assembly generates waltz;The support is used to support driving gear and passive gear, and the motor drives driving gear to rotate under the control of control instrument.By the application, the intermodulation test of different cable diameter cable assembly can be realized, the diameter of waltz can be kept unchanged during experiment;Fixing the cable assembly to be measured will not damage cable.

Description

Technical Field

[0001] The present invention relates to the field of testing technology, and in particular to a device and method for testing dynamic intermodulation of a coaxial cable assembly. Background Art

[0002] Coaxial cable assemblies and coaxial connectors are essential components of mobile communication networks. With the increasing demand for voice and data services, multi-band broadband transmission has become an essential requirement for both wired and wireless networks. Because many different frequency signals coexist within the same transmission channel, passive intermodulation (PIM) distortion (PIM) has become a significant factor limiting system capacity. Coaxial cable assemblies and matching RF coaxial connectors serve as the bridge between components and subsystems. If their performance is suboptimal, they are likely to generate high levels of PIM signals between different frequencies, causing distortion, noise, and clutter in the transmitted signal, impacting signal transmission rates. Intermodulation metrics are crucial in mobile communication systems, but they are typically tested under static conditions. However, in actual use, many situations are unpredictable and dynamic, necessitating dynamic intermodulation testing of coaxial cable assemblies and coaxial connectors. Summary of the Invention

[0003] In view of the above problems, the present invention is proposed to provide a material and method that overcomes the above problems or at least partially solves the above problems. In one aspect of the present invention, a dynamic intermodulation test device is provided, which includes: a driving gear, a passive gear, a dancing gear, a bracket, a motor, and a controller; the driving gear drives the dancing gear to rotate, and the passive gear cooperates with the driving gear to tighten the dancing gear; the dancing gear is used to fix the cable assembly to cause the cable assembly to dance; the bracket is used to support the driving gear and the passive gear, and the motor drives the driving gear to rotate under the control of the controller.

[0004] Optionally, the dancing gear is provided with a cable threading hole, a channel, an arc-shaped cable groove and a chuck, the cable assembly to be tested is fixed on the arc-shaped cable groove through the cable threading hole and the channel, and the chuck is used to fix the cable assembly to be tested.

[0005] Optionally, a bolt is provided on the dancing gear for fastening the cable assembly to be tested after the chuck fixes the cable assembly to be tested.

[0006] The present invention also provides a testing method for a dynamic intermodulation testing device, the method comprising: pre-setting a driving gear, a dancing gear and a driven gear, wherein the driving gear and the driven gear fix an axis and clamp the dancing gear together; setting parameters, and controlling a motor to work according to the parameters; the motor drives the driving gear to rotate, the driving gear drives the dancing gear to rotate, and the dancing gear drives the driven gear to rotate, causing a cable to be tested fixed on the dancing gear to dance; and testing the intermodulation of the cable to be tested in a dancing state.

[0007] Optionally, setting the parameters includes: calculating the parameters according to the diameter or radius of the coaxial cable assembly to be measured.

[0008] The technical solution provided in the embodiments of the present application has at least the following technical effects or advantages: it can perform intermodulation testing of cable assemblies with different cable diameters, and the dancing diameter can remain unchanged during the experiment; fixing the cable assembly to be tested will not damage the cable.

[0009] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0011] Figure 1 The figure shows the gear structure of the dynamic intermodulation test device proposed by the present invention;

[0012] Figure 2 The specific structure diagram of the dancing gear proposed by the present invention and the dancing trajectory diagram of the cable assembly to be tested are shown;

[0013] Figure 3 The figure shows the control and driving architecture of the dynamic intermodulation test device proposed by the present invention;

[0014] Figure 4 A flow chart showing a testing process of the dynamic intermodulation test device proposed in the present invention;

[0015] Figure 5 A block diagram of a detection system for intermodulation signals is shown;

[0016] Figure 6 、 7 The block diagrams of the detection systems for reverse and forward intermodulation signals are shown respectively. DETAILED DESCRIPTION

[0017] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0018] Passive intermodulation distortion (PIM) in cables is caused by internal nonlinearities. Coaxial cable assemblies are often considered linear components, but pure linear components do not exist. There are always some nonlinearities between the connector and the cable. These nonlinearities are often caused by skin effect, surface oxides, or poor contact. This application aims to test intermodulation in cable assemblies under dynamic conditions.

[0019] One aspect of the present invention provides a dynamic intermodulation test device, which includes: a driving gear, a passive gear, a dancing gear, a bracket, a motor and a controller; the driving gear drives the dancing gear to rotate, and the passive gear cooperates with the driving gear to tighten the dancing gear; the dancing gear is used to fix the cable assembly to cause the cable assembly to dance; the bracket is used to support the driving gear and the passive gear, and the motor drives the driving gear to rotate under the control of the controller.

[0020] The present invention cleverly utilizes the cooperation between the driving gear and the driven gear to tighten the dancing gear but does not fix the dancing gear. The rotation of the driving gear and the driven gear is used to make the cable assembly accommodated in the dancing gear dance, thereby constructing the dynamics of the cable assembly and then being able to test the intermodulation of the cable assembly under dynamic conditions.

[0021] As a preferred embodiment, Figure 1 As shown, the axes of the driving gear and the driven gear are respectively fixed on the vertical brackets. Before fixing the driving gear and the driven gear, the distance between the axes needs to be adjusted to ensure that the dancing gear can be clamped, or the distance between the axes is determined by the inner and outer diameters of the dancing gear.

[0022] like Figure 2 As shown, the dancing gear is equipped with a cable hole, a channel, an arc-shaped cable trough, and a chuck. The cable assembly under test is fixed to the arc-shaped cable trough through the cable hole and channel. The chuck is used to fix the cable assembly under test. The diameter of the cable hole is slightly larger than the diameter of the cable to facilitate cable passage. The channel runs from the cable hole to the arc-shaped cable trough and is used to guide the cable assembly under test from the cable hole to the arc-shaped cable trough.

[0023] The dancing gear is provided with a bolt for fastening the cable assembly to be tested after the chuck fixes the cable assembly to be tested.

[0024] like Figure 4 As shown, the process of testing using the dynamic intermodulation test device proposed by the present invention is as follows:

[0025] a. Pass the cable assembly through the cable hole of the dancing gear;

[0026] b. Move the cable assembly from the cable hole to the arc-shaped cable trough through the channel;

[0027] c. Fix the coaxial cable assembly with an arc-shaped chuck and tighten it with bolts;

[0028] d. Use the controller to calculate the experimental parameters according to the diameter of the cable to be tested;

[0029] e. Start the motor, which drives the gears to rotate according to the experimental parameters to complete the dancing test.

[0030] The control and driving parts of the present invention are as follows Figure 3 As shown in the figure, the motor drives the driving gear to rotate under the control of the controller. The driving gear drives the dancing gear, which in turn drives the driven gear to rotate. The dancing gear dances under the clamping of the driving gear and the driven gear.

[0031] The present invention also provides a testing method for a dynamic intermodulation testing device, the method comprising: pre-setting a driving gear, a dancing gear and a driven gear, wherein the driving gear and the driven gear fix an axis and clamp the dancing gear together; setting parameters, and controlling a motor to work according to the parameters; the motor drives the driving gear to rotate, the driving gear drives the dancing gear to rotate, and the dancing gear drives the driven gear to rotate, causing a cable to be tested fixed on the dancing gear to dance; and testing the intermodulation of the cable to be tested in a dancing state.

[0032] Setting parameters includes: calculating parameters according to the diameter or radius of the coaxial cable assembly to be tested.

[0033] The technical solution provided in the embodiments of the present application has at least the following technical effects or advantages: it can perform intermodulation testing of cable assemblies with different cable diameters, and the dancing diameter can remain unchanged during the experiment; fixing the cable assembly to be tested will not damage the cable.

[0034] The device can make the cable assembly in a dynamic state, and the intermodulation value is measured in the state. The application mainly improves the device and method for cable dancing, and the collection and measurement of the intermodulation signal are not described in detail. It should be noted that the application can use the existing intermodulation signal test system and method. The intermodulation signal test system is generally designed according to the modularization idea, and can be divided into four modules, namely, a radio frequency module, a power amplifier module, a radio frequency front end module and a control subsystem. The radio frequency module includes two independent signal sources and a receiving part of the intermodulation signal. The connection relationship of the four modules is shown in Figure 5 . The coaxial cable assembly is a typical passive two-port device, and the intermodulation signal test is divided into forward and reverse intermodulation tests. The main difference between them is the radio frequency front end module, and their system block diagrams are shown in Figure 6 、 7 . As can be seen from the block diagram in the above figure, the process of reverse intermodulation test is that the input signals of two signal sources are amplified and mixed, then input to the I port of the cable through the duplexer, and then connected to the matched low intermodulation load at the 2 port of the cable, and the level of the intermodulation signal is measured at the reflection end of the duplexer. The forward intermodulation test process is slightly more complex, that is, the input signals of two signal sources are amplified and mixed, then input to the I port of the cable through the duplexer, and then connected to another duplexer at the 2 port of the cable, and the output level of the intermodulation is measured at the reflection end of the duplexer. The specific test process for testing the coaxial cable assembly is as follows:

[0035] 1) intercept a certain length of the measured cable, pass one end through the cable hole on the dancing gear, fix it on the arc-shaped cable groove, then fix it with a chuck, and then make the joints at both ends;

[0036] 2) connect the one end of the measured piece with the joint to the RF output port of the intermodulation tester, and the other end to the low intermodulation load;

[0037] 3) in the case of conditions, place the measured system (including the load) with the above connection number in the shielding box;

[0038] 4) set the test parameters through the software on the PC, such as selecting the working frequency in the frequency band required to examine the intermodulation performance, so that the intermodulation product falls within the working frequency band. (Most test equipment manufacturers have built-in required frequency bands).

[0039] 5) adjust the output power to reach the required 20W, i.e. 43dBm in the standard.

[0040] 6) start the sweep program and measure. When the sweep is completed, read the test results.

[0041] The present invention can measure the intermodulation value of a coaxial cable assembly in a dynamic state, thereby fully detecting whether the performance of the cable is normal.

[0042] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0043] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the claims below, inventive aspects lie in less than all the features of the individual embodiments disclosed above. Accordingly, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of the invention.

[0044] It should be noted that the above embodiments illustrate rather than limit the present invention, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between brackets shall not be construed as limiting the claims.

Claims

1. A dynamic intermodulation test device, characterized in that: The device includes: a driving gear, a driven gear, a dancing gear, a bracket, a motor and a controller; the driving gear drives the dancing gear to rotate, the axes of the driving gear and the driven gear are respectively fixed on the bracket, and the distance between the axes of the two ensures that the driving gear and the driven gear clamp the dancing gear together; the dancing gear is used to fix the cable assembly, and the cable assembly accommodated in the dancing gear is caused to dance by the rotation of the driving gear and the driven gear, and the dancing gear is provided with a cable threading hole, a channel, and an arc-shaped cable groove, and the cable assembly to be tested is fixed to the arc-shaped cable groove through the cable threading hole and the channel; the dancing gear is provided with a chuck, and the chuck is used to fix the cable assembly to be tested; the bracket is used to support the driving gear and the driven gear, and the motor drives the driving gear to rotate under the control of the controller.

2. The dynamic intermodulation test device according to claim 1, further characterized in that: The dancing gear is provided with a bolt for fastening the cable assembly to be tested after the chuck fixes the cable assembly to be tested.

3. A dynamic intermodulation test method, characterized in that: The method includes: pre-setting a driving gear, a dancing gear and a driven gear, wherein the driving gear and the driven gear fix the axis and clamp the dancing gear together, the dancing gear is provided with a cable threading hole, a channel, and an arc-shaped cable groove, and the cable assembly to be tested is fixed on the arc-shaped cable groove through the cable threading hole and the channel; setting parameters, and controlling the motor to work according to the parameters; the motor drives the driving gear to rotate, the driving gear drives the dancing gear to rotate, and the dancing gear drives the driven gear to rotate, and the rotation of the driving gear and the driven gear is used to make the cable assembly accommodated in the dancing gear dance; testing the intermodulation of the cable to be tested in a dancing state.

4. The testing method according to claim 3, further characterized in that: Setting parameters includes: calculating parameters according to the diameter or radius of the coaxial cable assembly to be tested.

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