Non-shielded radio frequency cable test drum

Abstract

The utility model provides a kind of non-shielded radio frequency cable test roller.The test roller includes stainless steel cylinder;Foamed silica gel layer, the foamed silica gel layer is arranged on the outer surface of the stainless steel cylinder;At least two rows of non-conductive screws, the non-conductive screw is inserted into the foamed silica gel layer, the nail head of the non-conductive screw is suspended on the outside of the foamed silica gel layer, the row direction of each row of the non-conductive screw is parallel to the axis of the stainless steel cylinder, and the number and spacing of each row of the non-conductive screw are consistent.The test roller can avoid the influence of external frequency source on the measured non-shielded cable when testing radio frequency performance, and can reduce mechanical impact on the measured non-shielded cable.

Description

Technical Field

[0001] This utility model relates to the field of wire and cable technology, specifically to a test roller for unshielded radio frequency cables. Background Technology

[0002] Radio frequency (RF) cables are widely used in communications, radar, aerospace, and other fields, and their performance directly affects the transmission quality of the entire RF system. During the research, development, production, and quality inspection of cables, rigorous mechanical durability testing (such as repeated bending and torsion testing) and monitoring of RF performance (such as insertion loss, return loss, and phase stability) are required.

[0003] Test rollers are the core device for monitoring radio frequency performance during cable mechanical durability testing; however, current test rollers still need improvement. Utility Model Content

[0004] This utility model is based on the inventor's research and discoveries on the following issues:

[0005] Currently, the test rollers are made of polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF) and are equipped with non-conductive screws that are inserted into the roller from the inside. When the test cable is wound around the roller, a circular auxiliary rod is used on the outside of the roller, which is placed parallel to the screw. After winding, this rod is removed, and the extra space is used to compensate for the thermal expansion of the roller and cable in the oven.

[0006] The inventors discovered that using this test roller for testing easily causes mechanical impact to the test cable, and the test cable is susceptible to the influence of external frequency sources, leading to large errors in the test results. In addition, the need to set up and remove additional bars during testing increases the complexity of the test accessories and the testing process.

[0007] This utility model aims to at least partially solve one of the technical problems in the related art.

[0008] Therefore, in one aspect of this utility model, an unshielded radio frequency (RF) cable test roller is proposed. The test roller includes a stainless steel cylinder; a foamed silicone layer disposed on the outer surface of the stainless steel cylinder; and at least two rows of non-conductive screws inserted into the foamed silicone layer, with the screw heads suspended outside the foamed silicone layer. The direction of each row of non-conductive screws is parallel to the axis of the stainless steel cylinder, and the number and spacing of the non-conductive screws in each row are consistent. In this utility model, the stainless steel cylinder provides support and is not easily deformed, ensuring the test cable is fixed during testing. This prevents deformation of the test roller or movement of the test cable due to harsh environments such as heating or low temperatures, improving the stability of the test results. The foamed silicone layer effectively shields the test cable from interference from external frequency sources and provides a certain buffering effect, effectively reducing mechanical impact during cable winding, minimizing RF performance test errors, and improving the accuracy of RF performance test results. Furthermore, the foamed silicone layer can buffer the thermal expansion of the test cable in the oven, thus eliminating the need for additional rods and reducing the complexity of test accessories and the testing process.

[0009] Furthermore, the stainless steel cylinder includes: a hollow cylinder body; covers located at both ends of the cylinder body, with bearings provided at the covers; and a shaft arranged along the axial direction of the cylinder body, the shaft passing through the covers at both ends and extending to the outside of the covers, with the bearings mounted on the shaft.

[0010] Furthermore, the stainless steel cylinder body further satisfies at least one of the following conditions: the thickness of the cylinder body is 1.5-2.5mm; the diameter of the stainless steel cylinder body is 34-36cm and the length is 46-50cm; the material of the stainless steel cylinder body includes 316L or 304L.

[0011] Furthermore, the foamed silicone layer satisfies at least one of the following conditions: the dielectric constant of the foamed silicone layer is not greater than 1.4; the loss tangent of the foamed silicone layer is not greater than 0.005; and the thickness of the foamed silicone layer is 9.5-10.5 mm.

[0012] Furthermore, the foamed silicone layer is applied to the outer surface of the stainless steel cylinder using adhesive, wherein the adhesive has a temperature resistance rating of 50-200℃.

[0013] Furthermore, the adhesive material includes epoxy resin, polyurethane, silicone, or heterocyclic polymer.

[0014] Furthermore, the test roller includes two rows of non-conductive screws, which are arranged facing each other.

[0015] Furthermore, the non-conductive screw satisfies at least one of the following conditions: the material of the non-conductive screw includes nylon; the distance between two adjacent non-conductive screws is not less than 30 mm.

[0016] Furthermore, a wire take-up clamp is provided at each of the diagonal ends of the stainless steel cylinder. The inside of the clamp opening of the wire take-up clamp is provided with non-conductive silicone, and the clamp opening of the wire take-up clamp faces the outside of the stainless steel cylinder.

[0017] Furthermore, the device further includes a support frame comprising: two height-adjustable support portions, one end of each support portion having a groove for supporting the portion of the shaft extending to the outer side of the cover; two fixing portions having a triangular structure, the other end of each support portion being connected to the midpoint of the base of the fixing portion, and the support portion being perpendicular to the base of the fixing portion, the intersection point of the two sides of the fixing portion being located on the support portion; a connecting portion, both ends of which are respectively connected to the midpoint of the base of the two fixing portions; and rollers disposed at the intersection point of the sides and base of the two fixing portions. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic longitudinal section of an unshielded radio frequency cable test roller according to an embodiment of the present invention is shown.

[0020] Figure 2 A schematic longitudinal section of an unshielded radio frequency cable test roller according to another embodiment of the present invention is shown;

[0021] Figure 3 A perspective view of an unshielded radio frequency cable test roller according to an embodiment of the present invention is shown.

[0022] Figure label:

[0023] 100: Stainless steel cylinder; 110: Cylinder body; 120: Cover; 121: Bearing; 130: Shaft; 200: Foamed silicone layer; 300: Non-conductive screw; 310: Screw head; 400: Adhesive; 500: Cable take-up clamp; 610: Support part; 611: Groove; 621: Bottom edge; 622: Side edge; 630: Connecting part; 640: Roller. Detailed Implementation

[0024] The embodiments of this utility model are described in detail below. The embodiments described below are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product manual.

[0025] It should be noted that the cross-section of the test roller refers to the section parallel to the bottom surface of the roller, while the longitudinal section refers to the section perpendicular to the bottom surface of the roller and passing through the central axis.

[0026] In one aspect, this utility model provides a test roller for unshielded radio frequency cables. In some embodiments of this utility model, reference is made to... Figure 1 The test roller includes: a stainless steel cylinder 100, a foamed silicone layer 200, and at least two rows of non-conductive screws 300. The foamed silicone layer 200 is disposed on the outer surface of the stainless steel cylinder 100. The non-conductive screws 300 are inserted into the foamed silicone layer 200, with the screw heads 310 suspended outside the foamed silicone layer 200 (i.e., the screw heads 310 of the non-conductive screws 300 are higher than the outer surface of the foamed silicone layer 200). The direction of each row of non-conductive screws 300 is parallel to the axis of the stainless steel cylinder 100, and the number and spacing of each row of non-conductive screws 300 are consistent.

[0027] As mentioned earlier, the current test rollers are made of PTFE or PVDF materials. During the RF performance test, the test cable needs to be kept stationary and should not be touched during the test. However, the test roller will deform during the heating process, and the test cable wound on the test roller will also change position. That is, the test cable is forced to move during the test, which leads to unstable test results.

[0028] In this invention, the stainless steel cylinder of the test roller provides support and is resistant to deformation, ensuring the test cable remains fixed during testing. This prevents deformation of the test roller or movement of the test cable due to harsh environments such as heating or low temperatures, thus improving the stability of test results. The foamed silicone layer effectively shields the test cable from interference from external frequency sources and provides cushioning, effectively reducing mechanical impact during cable winding, minimizing RF performance testing errors, and improving the accuracy of RF performance test results. Furthermore, the foamed silicone layer buffers the thermal expansion of the test cable in the oven, eliminating the need for additional support rods and reducing the complexity of test accessories and procedures.

[0029] In some embodiments of this utility model, reference is made to Figure 2The stainless steel cylinder 100 includes a cylinder body 110, a cover 120, and a shaft 130. The cylinder body 110 has a hollow structure. The cover 120 is located at both ends of the cylinder body 110. A bearing 121 is provided at the cover 120. The shaft 130 is arranged along the axial direction of the cylinder body 110, passes through both ends of the cover 120, and extends to the outside of the cover 120. The bearing 121 is mounted on the shaft 130.

[0030] By designing the stainless steel cylinder as a hollow structure, the weight of the entire test drum can be reduced, making it easier to load and unload in the high and low temperature test chamber and reducing costs.

[0031] Covers are provided at both ends of the cylinder body to provide support and prevent deformation, thus allowing for a further reduction in the thickness of the stainless steel cylinder. In some embodiments of this invention, the thickness of the cylinder body 110 can be 1.5-2.5mm, for example, 1.5mm, 1.8mm, 2mm, 2.2mm, or 2.5mm. Even with a relatively thin cylinder body, good roundness can be maintained, and the foamed silicone layer on its outer surface can be well supported. The cover can have the same thickness as the cylinder body. In this invention, the cover can be a solid cover or a cover with a perforated pattern (such as...). Figure 3 (As shown), no special restrictions are imposed.

[0032] In some embodiments of this utility model, the diameter of the stainless steel cylinder 100 can be 34-36cm, for example, 34cm, 34.5cm, 35cm, 35.5cm, or 36cm, and the length can be 46-50cm, for example, 46cm, 47cm, 48cm, 49cm, or 50cm. These dimensions can effectively reduce the adverse effects of minimum radius bending of the cable during testing, such as distortion of key indicators like scattering parameters (S-parameters).

[0033] In some embodiments of this utility model, the stainless steel cylinder 100 is made of 316L or 304L. Tests are conducted in environments with high temperature, low temperature, high humidity, or normal temperature. These materials possess advantages such as good toughness, resistance to corrosion and rust in environments with alternating high and low temperatures and humidity, resistance to chloride ion corrosion, non-magnetic properties, ease of processing and welding, and low cost, thus well meeting the test requirements. In some preferred embodiments of this utility model, the stainless steel cylinder 100 is made of 316L.

[0034] A bearing 121 is installed at the cover 120 and mounted on the shaft 130. With the shaft 130 fixed, the cylinder 110 can rotate around the shaft 130 using the bearing 121. Thus, during the winding of the test cable, the test cable can be easily wound onto the foamed silicone layer on the outer surface of the cylinder simply by rotating the cylinder, making the operation simple.

[0035] In some embodiments of this invention, the dielectric constant of the foamed silicone layer 200 is no greater than 1.4. The foaming rate of the foamed silicone layer with a dielectric constant within the above range is above 80%. Using a foamed silicone layer with a dielectric constant within the above range can achieve stable impedance matching, minimizing reflection and maximizing energy transmission during RF cable testing, resulting in more stable and accurate testing of various RF parameters.

[0036] In some specific embodiments of this utility model, the dielectric constant of the foamed silicone layer 200 is 1.21. In this embodiment, the impedance is calculated by measuring the S-parameters (S11, S21). The measured |S11| ≤ −20dB, corresponding to an impedance deviation ≤ ±2Ω, indicating that the material can ensure the stability and impedance matching of the test system, thereby reducing measurement errors.

[0037] In some embodiments of this invention, the loss tangent of the foamed silicone layer 200 is no greater than 0.005. The loss tangent characterizes the absorption loss of radio frequency energy by the dielectric. If the loss tangent of the foamed silicone layer is greater than 0.005, it will lead to signal attenuation and indirectly disrupt the stability of impedance matching. In some specific embodiments of this invention, the loss tangent of the foamed silicone layer 200 can be 0.002-0.003, which can meet the high stability requirements.

[0038] In some embodiments of this invention, the thickness of the foamed silicone layer 200 can be 9.5-10.5 mm, for example, 9.5 mm, 9.8 mm, 10 mm, 10.2 mm, or 10.5 mm. If the thickness of the foamed silicone layer deviates from the above design value, it will cause the characteristic impedance to deviate from the target impedance (e.g., 50 Ω), leading to impedance mismatch. Specifically, if the thickness of the foamed silicone layer is too large, it will lead to enhanced signal reflection and deterioration of the return loss S11; if the thickness of the foamed silicone layer is too small, it will also cause signal reflection, and in severe cases, it will cause the standing wave ratio (VSWR) to exceed the system threshold, such as VSWR > 2.0.

[0039] By designing parameters such as the dielectric constant, loss tangent, and thickness of the foamed silicone layer, the RF parameters can be made more stable, thereby obtaining the truest test values.

[0040] In some embodiments of this utility model, reference is made to Figure 2 The foamed silicone layer 200 is applied to the outer surface of the stainless steel cylinder 100 using adhesive 400. The adhesive 400 has a temperature resistance rating of 50-200℃. The adhesive 400 can be made of epoxy resin, polyurethane, silicone, or heterocyclic polymers. These materials not only have good adhesion but also good temperature resistance, making them suitable for various testing environments.

[0041] In some embodiments of this utility model, the non-conductive screw 300 is inserted into the foamed silicone layer 200. Specifically, refer to... Figure 1 and Figure 2 The non-conductive screw 300 is inserted only into the foamed silicone layer 200. Alternatively, the non-conductive screw 300 can penetrate the foamed silicone layer 200 and be screwed into a pre-set threaded hole in the stainless steel cylinder 100 (this case is not shown in the figure). Furthermore, if the cylinder body 110 of the stainless steel cylinder 100 is a hollow structure, the non-conductive screw 300 can penetrate both the foamed silicone layer 200 and the cylinder body 110 simultaneously and be secured with a nut (this case is not shown in the figure). The specific placement of the non-conductive screw is not particularly limited, as long as it can be stably placed on the roller and serves to separate the test wires.

[0042] In some embodiments of this utility model, the non-conductive screw 300 is made of nylon. Nylon has advantages such as excellent insulation, good temperature resistance, good toughness, impact resistance, corrosion resistance, good processing performance, moderate mechanical strength at room temperature, and low cost, which can well meet the test conditions.

[0043] In some embodiments of this utility model, the distance d between two adjacent non-conductive screws 300 (e.g. Figure 2 The diameter of the non-conductive screw (as shown) should not be less than 30mm. Non-conductive screws are used as separators between each turn of the test cable, reducing mechanical impact on the test cable during testing and eliminating self-coupling between unshielded cables. Setting the distance between two adjacent non-conductive screws within the above-mentioned range effectively achieves the above effects. The number and spacing of non-conductive screws in each row are consistent, thus achieving the separation of the test cable. In this invention, the diameter of the non-conductive screw 300 can be 4mm.

[0044] In some specific embodiments of this utility model, the test roller has two rows of non-conductive screws 300, which are arranged facing each other, that is, each non-conductive screw 300 in the two rows is arranged facing each other (e.g., Figure 1 (As shown), in other words, the two rows of non-conductive screws 300 and the central axis of the cylinder 110 are located on the same plane.

[0045] Alternatively, in some other specific embodiments of this utility model, the test roller has four rows of non-conductive screws 300, with each two rows of non-conductive screws 300 forming a group. Each group of non-conductive screws 300 is located on the same plane as the central axis of the cylinder body 110, and the planes where the two groups of non-conductive screws 300 are located are perpendicular (this case is not shown in the figure).

[0046] In some embodiments of this utility model, reference is made to Figure 2 and Figure 3At each diagonal point of the stainless steel cylinder 100, a cable take-up clamp 500 is installed. The inner side of the clamp opening of the cable take-up clamp 500 is lined with non-conductive silicone, and the clamp opening faces outwards from the stainless steel cylinder 100. The cable take-up clamps prevent the test cable from loosening or shifting when wound around the test cylinder. The non-conductive silicone lining on the inner side of the clamp opening prevents mechanical damage to the test cable due to prolonged clamping. The clamp opening of the cable take-up clamp can extend to the outer side of the stainless steel cylinder (e.g., ...). Figure 3 (As shown), to facilitate clamping the test cable. It should be noted that the two cable take-up clamps 500 are located at opposite corners of the two ends of the stainless steel cylinder 100, meaning that the two cable take-up clamps 500 are located at opposite corners of the longitudinal section of the stainless steel cylinder 100.

[0047] There are no particular restrictions on the material and installation method of the take-up clamp; those skilled in the art can design it according to the actual situation. For example, the take-up clamp can be made of wood and fixed to the stainless steel cylinder by screws or rope.

[0048] In some embodiments of this utility model, reference is made to Figure 3 The test roller further includes a support frame, which comprises two height-adjustable support portions 610, two fixing portions (a triangular structure formed by a bottom edge 621 and a side edge 622), a connecting portion 630, and rollers 640. One end of each support portion 610 has a groove 611 for supporting the portion of the shaft 130 extending to the outside of the cover 120. The support portion 610 is perpendicular to the shaft 130, and the groove 611 supports and fixes the shaft 130, allowing the stainless steel cylinder 100 to rotate. The fixing portion has a triangular structure, and the other end of the support portion 610 is connected to the midpoint of the bottom edge 621 of the fixing portion, with the support portion 610 perpendicular to the bottom edge 621. The intersection of the two side edges 622 of the fixing portion is located on the support portion 610. Both ends of the connecting portion 630 are connected to the midpoints of the bottom edges 621 of the two fixing portions, respectively. The rollers 640 are located at the intersection of the side edges 622 and the bottom edge 621 of the two fixing portions, facilitating the movement of the entire testing device. The support frame facilitates the rotation and disassembly of the stainless steel cylinder, making it suitable for testing in various environments. The height adjustment method for the support is not particularly limited; those skilled in the art can design it according to the specific circumstances.

[0049] In the description of this utility model, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0050] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this specification. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0051] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A non-shielded radio frequency cable test drum characterized by, include: Stainless steel cylinder body; A foamed silicone layer is disposed on the outer surface of the stainless steel cylinder; At least two rows of non-conductive screws are inserted into the foamed silicone layer, with the screw heads suspended outside the foamed silicone layer. The direction of each row of non-conductive screws is parallel to the axis of the stainless steel cylinder, and the number and spacing of each row of non-conductive screws are consistent.

2. The unshielded radio frequency cable test drum of claim 1, wherein, The stainless steel cylinder includes: Hollow cylinder; The covers located at both ends of the cylinder body are provided with bearings; A shaft is provided along the axial direction of the cylinder body, the shaft passes through both end covers and extends to the outside of the cover, and the bearing is mounted on the shaft.

3. The unshielded radio frequency cable test drum of claim 2, wherein, The stainless steel cylinder further satisfies at least one of the following conditions: The thickness of the cylinder body is 1.5-2.5mm; The stainless steel cylinder has a diameter of 34-36cm and a length of 46-50cm; The stainless steel cylinder is made of 316L or 304L.

4. The unshielded radio frequency cable test drum of claim 1, wherein, The foamed silicone layer satisfies at least one of the following conditions: The dielectric constant of the foamed silicone layer is not greater than 1.4; The loss tangent of the foamed silicone layer is no greater than 0.

005. The thickness of the foamed silicone layer is 9.5-10.5 mm.

5. The unshielded radio frequency cable test drum of claim 1, wherein, The foamed silicone layer is applied to the outer surface of the stainless steel cylinder with adhesive, and the adhesive has a temperature resistance rating of 50-200℃.

6. The unshielded radio frequency cable test drum of claim 5, wherein, The adhesive is made of materials including epoxy resin, polyurethane, silicone, or heterocyclic polymers.

7. The unshielded RF cable test roller according to claim 1, characterized in that, The test roller includes two rows of non-conductive screws, which are arranged facing each other.

8. The unshielded radio frequency cable test drum of claim 1, wherein, The non-conductive screw satisfies at least one of the following conditions: The material of the non-conductive screw includes nylon; The distance between two adjacent non-conductive screws shall not be less than 30 mm.

9. The unshielded radio frequency cable test drum of claim 1, wherein, A wire take-up clamp is provided at each of the two diagonal ends of the stainless steel cylinder. The inside of the clamp opening of the wire take-up clamp is provided with non-conductive silicone, and the clamp opening of the wire take-up clamp faces the outside of the stainless steel cylinder.

10. The unshielded radio frequency cable test drum of claim 2, wherein, The system further includes a support, the support comprising: Two height-adjustable support portions, one end of which is provided with a groove for supporting the portion of the shaft extending to the outside of the cover; Two fixing parts, each having a triangular structure, with the other end of the support part connected to the midpoint of the base of the fixing part, and the support part perpendicular to the base of the fixing part; the intersection of the two sides of the fixing part is located on the support part. A connecting part, the two ends of which are respectively connected to the midpoints of the bottom edges of the two fixing parts; The roller is located at the intersection of the side and bottom edges of the two fixed parts.

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