CN220122090U

CN220122090U - Flexible transmission line

Info

Publication number: CN220122090U
Application number: CN202321196574.1U
Authority: CN
Inventors: 严霞霞; 高淑萍; 池静然; 宋杨; 李树旺
Original assignee: Sunway Communication Beijing Co Ltd
Current assignee: Sunway Communication Beijing Co Ltd
Priority date: 2023-05-17
Filing date: 2023-05-17
Publication date: 2023-12-01
Anticipated expiration: 2033-05-17

Abstract

The utility model discloses a flexible transmission line, which comprises a main body, wherein the main body comprises a bending region and a non-bending region, the two ends of the bending region are respectively connected with the non-bending region, the main body comprises a lower covering film layer, a circuit layer, a lower flexible medium layer, a colloid layer, an upper flexible medium layer, a stratum and an upper covering film layer which are sequentially connected in a laminated manner from bottom to top, the bending region is provided with a first vacant part and a second vacant part, the first vacant part extends from the top surface of the upper covering film layer to the top surface of the upper flexible medium layer, and the second vacant part extends from the bottom surface of the upper flexible medium layer to the top surface of the lower flexible medium layer; the circuit layer is provided with a radio frequency wire and a ground wire, the ground wire is connected with the stratum, the two sides of the radio frequency wire are respectively provided with the ground wire, and the radio frequency wire area in the bending area forms a differential structure. The circuit layer of the flexible transmission line forms a coplanar waveguide differential structure in the bending area, and the flexible transmission line has the advantages of low loss, high anti-interference, easy encapsulation and the like, and can realize repeated folding and bending of the flexible transmission line by 0-180 degrees.

Description

Flexible transmission line

Technical Field

The utility model relates to the technical field of radio frequency transmission, in particular to a flexible transmission line.

Background

In some electronic devices, the space of wearable electronic devices such as smart watches, folding screen cell phones, etc. is often limited, and conventional rigid radio frequency transmission lines are difficult to adapt to the small size and complex shape of the devices. The bendable transmission line (i.e., flexible transmission line) can adapt to space structures with various shapes by folding, bending and the like, so that the flexible transmission line is widely applied to wearable electronic equipment and other application occasions.

Existing repeatedly foldable transmission lines are typically flat flexible radio frequency transmission lines, which are folded and bent by a bendable conductor and a flexible insulating layer to fit in space-limited bending situations. However, the conventional flat flexible transmission line has large loss, so that the signal attenuation is large, and the conventional flat flexible transmission line is difficult to adapt to the environment with low loss and high anti-interference requirement.

Disclosure of Invention

The technical problems solved by the utility model are as follows: a low-loss flexible transmission line that can be repeatedly folded is provided.

In order to solve the technical problems, the utility model adopts the following technical scheme: the flexible transmission line comprises a main body, wherein the main body comprises a bending region and a non-bending region, two ends of the bending region are respectively connected with the non-bending region, the main body comprises a lower covering film layer, a circuit layer, a lower flexible medium layer, a colloid layer, an upper flexible medium layer, a stratum and an upper covering film layer which are sequentially laminated and connected from bottom to top, the bending region is provided with a first vacancy part and a second vacancy part, the first vacancy part extends from the top surface of the upper covering film layer to the top surface of the upper flexible medium layer, and the second vacancy part extends from the bottom surface of the upper flexible medium layer to the top surface of the lower flexible medium layer; the circuit layer is provided with a radio frequency wire and a ground wire, the ground wire is connected with the stratum, the ground wires are respectively arranged on two sides of the radio frequency wire, and the radio frequency wire area in the bending area forms a differential structure.

Further, the differential structure is in a long-distance race shape as a whole.

Further, the differential structure is provided with two Y-shaped parts and two straight line parts, the lengths of the two straight line parts are the same and are oppositely arranged, the two Y-shaped parts are respectively positioned at two ends of the straight line parts, and the Y-shaped parts are respectively connected with the radio frequency wire area positioned in the non-bending area and the two straight line parts.

Further, the connection part of the ground wire and the stratum is positioned in the non-bending area.

Further, the ground line is connected with the stratum through a metalized hole.

Further, the number of the metallized holes is multiple, and the metallized holes are arranged at intervals along the length direction of the ground wire.

Further, the non-bending area is provided with a connector, and the connector is communicated with the circuit layer.

Further, the connector is a board-to-board connector.

Further, the connector is disposed away from the bending region.

Further, the connector is located at an end of the non-bending region.

The utility model has the beneficial effects that: the circuit layer of the flexible transmission line forms a coplanar waveguide differential structure in the bending region, so that the flexible transmission line has the advantages of low loss, high anti-interference, easiness in packaging and the like; compared with a non-bending area, the stratum and the upper covering film layer can be reduced, and meanwhile, as the bending area has no stacking of the stratum, the colloid layer can be reduced, so that the thickness and hardness of the bending area are greatly improved, repeated folding and bending of the flexible transmission line by 0-180 degrees can be realized, and the flexible transmission line can be applied to a complex environment with high space utilization rate requirement due to low stacking thickness of the bending area; in addition, the existence of the first empty part and the second empty part can reduce the production consumable of the flexible transmission line, thereby reducing the manufacturing cost.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a flexible transmission line according to a first embodiment of the present utility model;

FIG. 2 is a partial cross-sectional view of a flexible transmission line where a bending region and a non-bending region are connected according to a first embodiment of the present utility model;

fig. 3 is a schematic structural diagram of a flexible transmission line with a hidden lower cover film layer according to a first embodiment of the present utility model;

fig. 4 is an enlarged view at a in fig. 3.

FIG. 5 is a graph of the insertion loss of a control group according to the first embodiment of the present utility model;

FIG. 6 is a second graph of insertion loss of the control group according to the first embodiment of the present utility model;

FIG. 7 is an isolated view of a control group according to a first embodiment of the present utility model;

FIG. 8 is a graph of the insertion loss of the experimental group in accordance with the first embodiment of the present utility model;

FIG. 9 is a second graph of insertion loss for the experimental set in accordance with the first embodiment of the utility model;

FIG. 10 is an isolated view of an experimental set in accordance with one embodiment of the present utility model.

Reference numerals illustrate:

1. a lower cover film layer;

2. a circuit layer; 21. a radio frequency line; 22. a ground wire; 23. a differential structure; 231. a Y-shaped part; 232. a straight line portion;

3. a lower flexible dielectric layer;

4. a colloid layer;

5. an upper flexible dielectric layer;

6. a formation;

7. covering a film layer;

8. a first void portion;

9. a second void portion;

10. and metallizing the holes.

Detailed Description

The achievement of the objects, functional features and advantages of the present utility model will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that, in the embodiment of the present utility model, directional indications such as up, down, left, right, front, and rear … … are referred to, and the directional indication is merely used to explain the relative positional relationship, movement conditions, and the like between the components in a specific posture such as that shown in the drawings, and if the specific posture is changed, the directional indication is changed accordingly.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present utility model, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature.

In addition, if the meaning of "and/or" is presented throughout this document to include three parallel schemes, taking "and/or" as an example, including a scheme, or a scheme that is satisfied simultaneously. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

Example 1

Referring to fig. 1 to 10, a first embodiment of the present utility model is as follows: a flexible transmission line for transmitting radio frequency signals.

As shown in fig. 1 to 4, the flexible transmission line includes a main body, the main body includes a bending region and a non-bending region, two ends of the bending region are respectively connected with the non-bending region, and the bending region and the non-bending region are of an integrated structure.

The main body comprises a lower covering film layer 1, a circuit layer 2, a lower flexible medium layer 3, a colloid layer 4, an upper flexible medium layer 5, a stratum 6 and an upper covering film layer 7 which are sequentially connected in a laminated manner from bottom to top, the bending region is provided with a first empty part 8 and a second empty part 9, the first empty part 8 extends from the top surface of the upper covering film layer 7 to the top surface of the upper flexible medium layer 5, and the second empty part 9 extends from the bottom surface of the upper flexible medium layer 5 to the top surface of the lower flexible medium layer 3; in the actual production process, the first empty part 8 may be formed by an uncovering process, or the upper covering film 7 may be hollowed out and the stratum 6 may be etched before lamination and lamination of the main body, so that the laminated and laminated main body is formed with the first empty part 8. It will be appreciated that the presence of the second recess 9 directly leaves the bending zone free of the glue layer 4. In the non-bending area, the line layer 2 and the stratum 6 are filled with flexible dielectric materials, so that transmission signals can be isolated and protected, transmission loss is reduced, meanwhile, the upper cover film layer 7 on the upper surface of the flexible transmission line can protect the stratum 6, the lower cover film layer 1 on the lower surface of the flexible transmission line can protect the line layer 2, abrasion and corrosion are prevented, and the transmission loss and signal interference of the flexible transmission line are further reduced.

The circuit layer 2 is provided with a radio frequency line 21 and a ground line 22, the ground line 22 is connected with the stratum 6, and the two sides of the radio frequency line 21 are respectively provided with the ground line 22, that is, the circuit layer 2 and the stratum 6 form a coplanar waveguide structure; in order to eliminate the influence of the removal of the region of the stratum 6 corresponding to the bending region, improve the anti-interference performance of the flexible transmission line, reduce the transmission loss of the flexible transmission line, and form a differential structure 23 in the region of the radio frequency line 21 in the bending region.

As shown in fig. 3 and 4, specifically, the differential structure 23 is in a long-distance track shape as a whole. In this embodiment, the differential structure 23 has two Y-shaped portions 231 and two straight portions 232, the lengths of the two straight portions 232 are the same and are disposed opposite to each other, the two Y-shaped portions 231 are respectively located at two ends of the straight portions 232, and the Y-shaped portions 231 are respectively connected to the radio frequency wire 21 region located in the non-bending region and the two straight portions 232. The two straight portions 232 of each rf line 21 are arranged in parallel, so that the electric field and the magnetic field components along the direction of the rf line 21 can be coupled to each other and form a coplanar waveguide differential form, and the flexible transmission line has the advantages of low transmission loss and high interference resistance.

The connection between the ground wire 22 and the stratum 6 is located in the non-bending area, and the ground wire 22 is connected with the stratum 6 through the metallized holes 10. In this embodiment, the number of the metallized holes 10 is plural, and the metallized holes 10 are arranged at intervals along the length direction of the ground wire 22.

For facilitating the connection of the flexible transmission line to external electronic devices, the non-bending area is provided with a connector (not shown in the figure) which is in communication with the circuit layer 2. Optionally, the connector is a board-to-board connector.

The connector is disposed away from the bending region. In this embodiment, the connector is located at an end of the non-bending region.

In order to fully explain the advantage that the bending area in the flexible transmission line adopts a differential structure, the inventor carries out a simulation experiment, the experimental group is the flexible transmission line described in the embodiment, the bending area of the flexible transmission line has a differential structure, and the comparison group is different from the experimental group only in that the bending area does not have the differential structure, namely, the comparison group is only the flexible transmission line adopting the coplanar waveguide structure.

FIG. 5 is a graph of insertion loss in a control group;

FIG. 6 is a second graph of insertion loss for the control group;

FIG. 7 is an isolated view of a control group;

FIG. 8 is a graph of insertion loss for the experimental set I;

FIG. 9 is a second insertion loss plot of the experimental set;

FIG. 10 is an isolated plot of the experimental group;

as can be seen from fig. 5, 6, 8 and 9, the insertion loss of the experimental group in the 5G frequency band and the 10G frequency band is reduced compared with that of the control group, the insertion loss of the experimental group in the 5G frequency band and the 10G frequency band is respectively reduced by 1dB, and meanwhile, the experimental group does not have a resonance region in the 8G working frequency band; as can be seen from fig. 7 and fig. 10, compared with the control group, the signal interference of the experimental group is reduced, the isolation degree reaches more than 30dB, and the transmission line has good isolation effect.

Therefore, the flexible transmission line of the embodiment has good impedance matching characteristics and low transmission loss, and is beneficial to signal transmission and signal quality maintenance.

The foregoing description is only of the optional embodiments of the present utility model, and is not intended to limit the scope of the utility model, and all the equivalent structural changes made by the description of the present utility model and the accompanying drawings or the direct/indirect application in other related technical fields are included in the scope of the utility model.

Claims

1. The utility model provides a flexible transmission line, includes the main part, the main part includes bending area and non-bending area, bending area's both ends are connected with respectively non-bending area, the main part includes by supreme laminating continuous lower cover rete, circuit layer, lower flexible dielectric layer, colloid layer, goes up flexible dielectric layer, stratum and last cover rete in proper order down, its characterized in that: the bending region is provided with a first vacant part and a second vacant part, the first vacant part extends from the top surface of the upper covering film layer to the top surface of the upper flexible medium layer, and the second vacant part extends from the bottom surface of the upper flexible medium layer to the top surface of the lower flexible medium layer; the circuit layer is provided with a radio frequency wire and a ground wire, the ground wire is connected with the stratum, the ground wires are respectively arranged on two sides of the radio frequency wire, and the radio frequency wire area in the bending area forms a differential structure.

2. The flexible transmission line of claim 1, wherein: the differential structure is in a long-distance race shape as a whole.

3. The flexible transmission line of claim 2, wherein: the differential structure is provided with two Y-shaped parts and two straight line parts, the lengths of the two straight line parts are the same and are oppositely arranged, the two Y-shaped parts are respectively positioned at two ends of the straight line parts, and the Y-shaped parts are respectively connected with the radio frequency line area positioned in the non-bending area and the two straight line parts.

4. The flexible transmission line of claim 1, wherein: and the connection part of the ground wire and the stratum is positioned in the non-bending area.

5. The flexible transmission line of claim 4, wherein: the ground wire is connected with the stratum through a metallized hole.

6. The flexible transmission line of claim 5, wherein: the number of the metallized holes is multiple, and the metallized holes are arranged at intervals along the length direction of the ground wire.

7. The flexible transmission line of claim 1, wherein: the non-bending area is provided with a connector, and the connector is communicated with the circuit layer.

8. The flexible transmission line of claim 7, wherein: the connector is a board-to-board connector.

9. The flexible transmission line of claim 7, wherein: the connector is disposed away from the bending region.

10. The flexible transmission line of claim 9, wherein: the connector is positioned at the end of the non-bending area.