A low cost 50-75 ohm low PIM coaxial line impedance transition section

Abstract

The application discloses a low-cost 50-75 ohm low-PIM coaxial line impedance adapter section, which comprises a conversion section outer conductor metal groove; a dielectric filling layer and a conversion section inner conductor metal groove are inlaid in the conversion section outer conductor metal groove in sequence; through holes are arranged at both ends of the conversion section outer conductor metal groove, both ends of the dielectric filling layer and both ends of the conversion section inner conductor metal groove; a to-be-measured coaxial line inner conductor is inserted into the through hole at the end of the conversion section inner conductor metal groove through the through hole at the end of the conversion section outer conductor metal groove and the through hole at the end of the dielectric filling layer; and a to-be-measured coaxial line outer conductor is welded on the outer wall of the conversion section outer conductor metal groove; the to-be-measured coaxial line inner conductor is welded on the conversion section inner conductor metal groove in a via hole welding mode, and the adapter section has the characteristics of simple structure and low cost.

Description

Technical Field

[0001] This invention relates to an adapter section, specifically a low-cost 50-75 ohm low PIM coaxial line impedance adapter section. Background Technology

[0002] Currently, known coaxial cable 50-75 ohm conversion requires first using a specialized matching crimp structure to connect the adapter to the cable, and then using a 50-75 ohm adapter to connect the two cable sections. The crimp structure physically presses against the inner and outer conductors of the cable, leading to contact uncertainty and thus instability in the PIM (Position Indicator Mobility) rating. Furthermore, different types of crimp adapters are needed for different cable diameters, increasing conversion costs and structural complexity. Therefore, there is an urgent need for a fast, low-cost conversion solution that can achieve low PIM for cables with common impedances. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a low-cost 50-75 ohm low PIM coaxial impedance adapter segment, which has the characteristics of simple structure and low cost.

[0004] To achieve the above objectives, the present invention discloses a low-cost 50-75 ohm low PIM coaxial line impedance transition section including an outer conductor metal groove of the transition section;

[0005] The outer conductor metal groove of the switching section is sequentially inlaid with a dielectric filling layer and an inner conductor metal groove of the switching section. Through holes are provided at both ends of the outer conductor metal groove, both ends of the dielectric filling layer, and both ends of the inner conductor metal groove of the switching section. The inner conductor of the coaxial line to be tested passes through the through holes at the ends of the outer conductor metal groove and the dielectric filling layer and is inserted into the through hole at the ends of the inner conductor metal groove of the switching section. The outer conductor of the coaxial line to be tested is welded to the outer wall of the outer conductor metal groove of the switching section. The inner conductor of the coaxial line to be tested is welded to the inner conductor metal groove of the switching section by through-hole welding.

[0006] The length of the long side of the conversion segment is one-quarter of the wavelength of the center frequency of the frequency band in use.

[0007] The wavelength is determined by the shape of the outer conductor metal groove and the inner conductor metal groove of the transition section, as well as the dielectric constant of the dielectric filling layer.

[0008] The outer conductor metal groove of the transition section, the dielectric filling layer, and the inner conductor metal groove of the transition section constitute a microstrip line structure with rolled-up edges.

[0009] The outer conductor metal slot of the transition section is equivalent to the ground plane conductor of a microstrip transmission line.

[0010] The dielectric filling layer is equivalent to the dielectric layer of a microstrip transmission line.

[0011] The conductor metal slot in the transition section is equivalent to the upper conductor signal line of a microstrip transmission line.

[0012] The thickness and size of the dielectric filling layer determine the size of the transition section.

[0013] The present invention has the following beneficial effects:

[0014] In practical operation, the low-cost 50-75 ohm low PIM coaxial cable impedance conversion section of this invention involves the inner conductor of the coaxial cable under test passing through the through-hole at the end of the outer conductor metal groove of the conversion section and the through-hole at the end of the dielectric filling layer, and being inserted into the through-hole at the end of the inner conductor metal groove of the conversion section. The outer conductor of the coaxial cable under test is welded to the outer wall of the outer conductor metal groove of the conversion section. The inner conductor of the coaxial cable under test is welded to the inner conductor metal groove of the conversion section using through-hole welding. The structure is simple and can significantly reduce the cost of 50-75 ohm cable conversion in communication base stations and testing applications, and increase the reliability of conversion. Attached Figure Description

[0015] Figure 1 This is a cross-sectional view of the present invention;

[0016] Figure 2 This is a structural diagram of the present invention.

[0017] Among them, 1 is the outer conductor metal groove of the transition section, 2 is the dielectric filling layer, 3 is the inner conductor metal groove of the transition section, 4 is the outer conductor of the coaxial line to be tested, and 5 is the inner conductor of the coaxial line to be tested. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, not all embodiments, and are not intended to limit the scope of the present invention. Furthermore, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion regarding the concepts disclosed in the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0019] The accompanying drawings show structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not drawn to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0020] refer to Figure 1 and Figure 2 The low-cost 50-75 ohm low PIM coaxial impedance transition section of the present invention includes an outer conductor metal groove 1, a dielectric filling layer 2, and an inner conductor metal groove 3.

[0021] The outer conductor metal groove 1 of the conversion section is sequentially inlaid with a dielectric filling layer 2 and an inner conductor metal groove 3 of the conversion section. Through holes are provided at both ends of the outer conductor metal groove 1, both ends of the dielectric filling layer 2, and both ends of the inner conductor metal groove 3 of the conversion section. The inner conductor 5 of the coaxial line to be tested passes through the through holes at the ends of the outer conductor metal groove 1 and the dielectric filling layer 2 and is inserted into the through hole at the end of the inner conductor metal groove 3 of the conversion section. The outer conductor 4 of the coaxial line to be tested is welded to the end of the outer conductor metal groove 1 of the conversion section. The inner conductor 5 of the coaxial line to be tested is welded to the inner conductor metal groove 3 of the conversion section by through-hole welding. Preferably, the through hole is a round hole.

[0022] refer to Figure 2 The length of the long side of the conversion segment described in this invention is one-quarter of the wavelength of the center frequency of the operating frequency band. This wavelength is determined by the shape of the outer conductor metal groove 1 and the inner conductor metal groove 3 of the conversion segment and the dielectric constant of the dielectric filling layer 2.

[0023] In this embodiment, the outer conductor metal groove 1, the dielectric filling layer 2, and the inner conductor metal groove 3 of the switching section constitute a microstrip line structure with rolled-up edges. The outer conductor metal groove 1, the dielectric filling layer 2, and the inner conductor metal groove 3 of the switching section are equivalent to the ground plane conductor, the dielectric layer, and the upper conductor signal line of the microstrip transmission line, respectively. The thickness and size of the dielectric filling layer 2 determine the size of the switching section.

[0024] It should be noted that this invention achieves isolation between the transmission line signal line and the ground line by setting a dielectric filling layer 2 between the outer conductor metal groove 1 and the inner conductor metal groove 3 of the conversion section. Low PIM control of the metal plating layer is achieved through pure silver and ternary alloy plating processes. Furthermore, for different frequency band applications, impedance adjustment of the transition section can be achieved by controlling the size and spacing of the outer conductor metal groove 1 and the inner conductor metal groove 3, as well as the thickness of the dielectric filling layer 2. In use, the 50-ohm and 75-ohm cables at both ends need to be stripped to expose the inner and outer conductors. The outer conductor is soldered to the outer conductor metal groove 1 of the conversion section, and the inner conductor is soldered into a through-hole in the inner conductor metal groove 3 of the conversion section. During use, a low PIM connection is achieved by filling the gap between the cable and the through-hole with an appropriate amount of solder.

[0025] The adapter section described in this invention is not only suitable for testing 75-ohm cables, but can also be used to achieve impedance conversion connections for cables in specific application scenarios.

[0026] It should be noted that this invention utilizes embedded low-PIM metal transmission lines through through-hole soldering to quickly achieve low-cost and miniaturized cable impedance conversion, which can significantly reduce the cost of 50-75 ohm cable conversion in communication base stations and testing applications, and increase the reliability of conversion.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A low-cost 50-75 ohm low PIM coaxial line impedance adapter, characterized in that, Including the outer conductor metal groove of the transition section (1); The outer conductor metal groove (1) of the transition section is inlaid with a dielectric filling layer (2) and an inner conductor metal groove (3) of the transition section in sequence. Through holes are provided at both ends of the outer conductor metal groove (1), both ends of the dielectric filling layer (2), and both ends of the inner conductor metal groove (3). The inner conductor (5) of the coaxial line to be tested passes through the through holes at the ends of the outer conductor metal groove (1) and the dielectric filling layer (2) and is inserted into the through hole at the end of the inner conductor metal groove (3). The outer conductor (4) of the coaxial line to be tested is welded to the outer wall of the outer conductor metal groove (1) of the transition section. The inner conductor (5) of the coaxial line to be tested is welded to the inner conductor metal groove (3) of the transition section by through-hole welding. The length of the longer side of the conversion segment is one-quarter of the wavelength of the center frequency of the used frequency band; The outer conductor metal slot (1) of the transition section is equivalent to the ground plane conductor of a microstrip transmission line; The dielectric filling layer (2) is equivalent to the dielectric layer of a microstrip transmission line; The inner conductor metal groove (3) of the transition section is equivalent to the upper conductor signal line of the microstrip transmission line.

2. The low-cost 50-75 ohm low PIM coaxial line impedance adapter section according to claim 1, characterized in that, The wavelength is determined by the shape of the outer conductor metal groove (1) and the inner conductor metal groove (3) of the transition section and the dielectric constant of the dielectric filling layer (2).

3. The low-cost 50-75 ohm low PIM coaxial line impedance adapter section according to claim 1, characterized in that, The outer conductor metal groove (1), the dielectric filling layer (2), and the inner conductor metal groove (3) of the transition section constitute a microstrip line structure with rolled-up edges.

4. The low-cost 50-75 ohm low PIM coaxial line impedance adapter section according to claim 1, characterized in that, The thickness and size of the dielectric filling layer (2) determine the size of the conversion section.

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