Multi-band antenna

Abstract

The utility model discloses a multi-band antenna, which comprises a base material, the base material comprises a first surface and a second surface which are oppositely arranged, the first surface is provided with a first conductive layer, the first conductive layer comprises a main body part which is arranged in a bending manner, the first end of the main body part is provided with a first extension section in an extending manner along a second direction, and the second end of the main body part is provided with a second extension section in an extending manner. The second end of the main body part extends along the first direction to form a third extension section, a second extension section extends along the first direction or the second direction between the first end and the second end of the main body part, and the second surface is provided with a second conductive layer. According to the multi-band antenna provided by the utility model, not only can signals within the frequency band range of 5925 MHz to 7125 MHz be transmitted, but also the efficiency is higher when signals within the frequency band range of 2400 MHz to 2500 MHz and the frequency band range of 5150 MHz to 5850 MHz are transmitted, the communication efficiency is higher, and the power consumption of the multi-band antenna is lower; compared with a multi-band antenna in the prior art, the multi-band antenna provided by the utility model has a smaller area, so that the cost is saved, and the use flexibility is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of antenna design, specifically relates to a multi -band antenna. BACKGROUND

[0002] As Figure 1 The schematic diagram of the wiring surface of the antenna in the prior art is shown, and this kind of antenna is mostly used in the palm game machine, the frequency range of this type of equipment is 2400MHz~2500MHz and 5150MHz~5850MHz, but this kind of multi -band antenna resonates relatively poor in the frequency band of 5925MHz~7125MHz, does not support the frequency band, leads to the certain limitation of multi -band antenna when using, secondly, the area of this kind of multi -band antenna is relatively large, and the corresponding palm game machine when using also has the relatively large area, is inconvenient to use.

[0003] The information disclosed in this BACKGROUND section is only for the purpose of increasing the understanding of the background of the present utility model and should not be taken as an acknowledgement or any form of suggestion that this information forms prior art that is publicly known. SUMMARY

[0004] The utility model aims at providing a kind of multi -band antenna, it can solve the technical problem of narrow bandwidth, large area of multi -band antenna in prior art.

[0005] In order to realize the above-mentioned purpose, the utility model one specific implementation provides a kind of multi -band antenna, including base material, the base material includes oppositely arranged first surface and second surface, first conductive layer is equipped on the first surface, the first conductive layer includes the main part of bending arrangement, the first end of the main part is equipped with first extension along second direction, the second end of the main part is equipped with third extension along first direction, the first end and the second end of main part are equipped with second extension along first direction or second direction, second conductive layer is equipped on the second surface.

[0006] In one or more embodiments of the utility model, the main part includes first main part, third main part and second main part between first main part and third main part, first connecting part is connected between first main part and second main part, second connecting part is connected between second main part and third main part, the first extension is extended from first main part along second direction, the second extension is extended from second main part along second direction, the third extension is extended from third main part along first direction, and the size of first extension along first direction is less than the size of first main part along first direction, the size of second extension along second direction is less than the size of second main part along second direction, and the size of third extension along first direction is less than the size of third main part along first direction.

[0007] In one or more embodiments of the present application, the first connecting portion comprises at least one first connecting segment distributed along the first direction and at least one second connecting segment distributed along the second direction, the size of the first connecting segment along the second direction is smaller than the size of the first main body portion along the second direction, and the size of the second connecting segment along the first direction is smaller than the size of the second main body portion along the first direction.

[0008] The second connecting portion comprises at least one fifth connecting segment distributed along the first direction, the size of the fifth connecting segment along the second direction is smaller than the size of the second main body portion along the second direction and the size of the third main body portion along the second direction.

[0009] In one or more embodiments of the present application, the main body portion comprises a fourth main body portion and a fifth main body portion, the third connecting portion is connected between the fourth main body portion and the fifth main body portion, the first extending segment extends from the fourth main body portion along the second direction, the second extending segment and the third extending segment both extend from the fifth main body portion away from the second main body portion along the first direction, the second extending segment is away from the third connecting portion, the third extending segment is close to the third connecting portion, and the size of the first extending segment along the first direction is smaller than the size of the fourth main body portion along the first direction, and the size of the second extending segment and the third extending segment along the second direction are both smaller than the size of the fifth main body portion along the second direction.

[0010] In one or more embodiments of the present application, the third connecting portion comprises at least one sixth connecting segment distributed along the first direction and at least one seventh connecting segment distributed along the second direction, the size of the sixth connecting segment along the second direction is smaller than the size of the first main body portion along the second direction, and the size of the seventh connecting segment along the first direction is smaller than the size of the second main body portion along the first direction.

[0011] In one or more embodiments of the present application, the third conductive layer covering part of the first main body portion is arranged on the first surface, the third conductive layer is grounded, the covering film covering part of the first conductive layer is arranged on the first surface, and the covering film is located in the region of the first surface which is not covered by the third conductive layer.

[0012] In one or more embodiments of the present application, the feedback point and the grounding point are arranged on the second conductive layer in a spaced distribution.

[0013] In one or more embodiments of the present application, the first adhesive layer is arranged on the second surface, the first adhesive layer is located on part of the second conductive layer, and the first adhesive layer covers the region of the second conductive layer other than the feedback point and the grounding point.

[0014] In one or more embodiments of the present application, the first adhesive layer, the cover feedback point and the grounding point are covered with release paper, and the release paper has a hand tearing part beyond the edge of the first adhesive layer.

[0015] In one or more embodiments of the present application, the first conductive layer and the base material are provided with a second adhesive layer, the first conductive layer includes a first calendered layer close to the first double-sided adhesive layer and a first electroplated layer away from the first double-sided adhesive layer; the second conductive layer and the base material are provided with a third adhesive layer, and the second conductive layer includes a second calendered layer close to the third adhesive layer and a second electroplated layer away from the third adhesive layer.

[0016] Compared with the prior art, the multi-band antenna in the present application can not only transmit signals in the frequency range of 5925MHz-7125MHz, but also has an average efficiency of 1.83dB higher than that of the multi-band antenna in the prior art when transmitting signals in the frequency range of 2400MHz-2500MHz, and an average efficiency of 0.61dB higher than that of the multi-band antenna in the prior art when transmitting signals in the frequency range of 5150MHz-5850MHz. The multi-band antenna in the present application not only can be applied to a wider frequency range, but also has higher communication efficiency and lower power consumption.

[0017] The multi-band antenna in the present application has a smaller area than the multi-band antenna in the prior art, which not only saves cost but also increases flexibility in use. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments described in the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0019] Figure 1 The structure diagram of the first surface of the multi-band antenna in the prior art;

[0020] Figure 2 The structure diagram of the second surface of the multi-band antenna in the prior art;

[0021] Figure 3 The structure diagram of the multi-band antenna in the prior art;

[0022] Figure 4 The structure diagram of the first surface of the multi-band antenna in a specific embodiment of the present application;

[0023] Figure 5Structure diagram of the second surface of the multi-band antenna in one specific embodiment of the present application;

[0024] Figure 6 Structure diagram of the first conductive layer of the multi-band antenna in the first embodiment of the present application;

[0025] Figure 7 Structure diagram of the second conductive layer of the multi-band antenna in the first embodiment of the present application;

[0026] Figure 8 Structure diagram of the multi-band antenna in one specific embodiment of the present application;

[0027] Figure 9 Structure diagram of the multi-band antenna in another specific embodiment of the present application;

[0028] Figure 10 Structure diagram of the first conductive layer of the multi-band antenna in the second embodiment of the present application;

[0029] Figure 11 Structure diagram of the second conductive layer of the multi-band antenna in the second embodiment of the present application;

[0030] Figure 12 Wiring diagram of the first conductive layer in the first embodiment of the present application;

[0031] Figure 13 Structure diagram of the first connecting part in the first embodiment of the present application;

[0032] Figure 14 Wiring diagram of the first conductive layer in the second embodiment of the present application;

[0033] Figure 15 Structure diagram of the third connecting part in the second embodiment of the present application;

[0034] Figure 16 Size annotation diagram of the multi-band antenna in the first embodiment of the present application;

[0035] Figure 17 Size annotation diagram of the multi-band antenna in the second embodiment of the present application;

[0036] Figure 18 Resonance fold line diagram of the multi-band antenna in the prior art;

[0037] Figure 19 Resonance fold line diagram of the multi-band antenna in the present application;

[0038] Figure 20 Transmission efficiency test result diagram of the multi-band antenna in the prior art;

[0039] Figure 21 The utility model discloses a multi-band antenna's transmission efficiency test result graph.

[0040] Main marks include:

[0041] 1, base material, 2, conductive layer, 21, first conductive layer, 211, first calendered layer, 212, first electroplated layer, 213, first main part, 214, second main part, 215, third main part, 216, first extension section, 217, second extension section, 218, third extension section, 219, first connecting part, 2191, first connecting section, 2192, second connecting section, 2193, third connecting section, 2194, fourth connecting section, 2110, second connecting part, 21101, fifth connecting section, 2111, fourth main part, 2112, fifth main part, 2113, fourth connecting part, 22, second conductive layer, 23, third conductive layer, 3, welding spot, 4, viscose layer, 5, back adhesive layer, 6, release paper, 61, hand tearing part, 7, ink layer, 8, silk screen layer, 9, stress hole, 10, positioning hole. DETAILED DESCRIPTION

[0042] In order to make the personnel in the art better understand the technical scheme in the utility model, the technical scheme in the embodiment of the utility model will be described clearly and completely below in combination with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment in the utility model, all other embodiments obtained by the person skilled in the art without creative labor should belong to the protection scope of the utility model.

[0043] In the description of the utility model, it is understood that the orientation or position relation indicated by the terms "vertical", "horizontal", "top", "bottom", "upper", "lower", "front", "back" and the like is the orientation or position relation based on the orientation or position relation shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as the limitation to the utility model.

[0044] As Figures 1 to 3The diagrams shown are structural diagrams of the front and back sides and a stacked structure diagram of an existing multi-band antenna in the background art. The multi-band antenna includes a substrate 1, a conductive layer 2 disposed on the substrate 1, solder joints 3 electroplated on the conductive layer 2, an adhesive layer 4 disposed on the conductive layer 2, another substrate 1 disposed on the conductive layer 2, and an adhesive backing layer 5 disposed on the substrate 1. The conductive layer 2 has two radiating segments for transmitting signals. These two radiating segments can transmit signals in the frequency range of 2400MHz~2500MHz and 5150MHz~5850MHz. However, the frequency is relatively low when transmitting signals in these two ranges. In the frequency range of 5925MHz~7125MHz, the resonance capability of this type of antenna is poor and cannot support this frequency band. A lot of space is wasted on the entire antenna, resulting in a large overall area.

[0045] In response to the above problems, such as Figures 4 to 11 As shown, the multi-band antenna of this utility model includes a substrate 1, which has a first surface and a second surface arranged opposite to each other. A first conductive layer 21 is bonded to the first surface by a first adhesive layer 41, and a second conductive layer 22 is bonded to the second surface by a second adhesive layer 42. A third conductive layer 23 is provided on the first conductive layer 21. After being powered on, the first conductive layer 21 and the second conductive layer 22 have a potential difference, and the first conductive layer 21 can receive signals of different frequency bands. The third conductive layer 23 is used for grounding and can reflect electromagnetic waves, thereby enhancing the anti-interference capability of the first conductive layer 21. The second conductive layer 22 is provided with solder joints, including a feedback point 311 and a grounding point 312. The grounding point 312 connects the antenna to the ground, which can improve the antenna's radiation efficiency and protect the antenna from external interference. The feedback point 311 is used to provide the antenna's feedback signal to external devices, thereby shaping the signal waveform radiated by the antenna to optimize the performance of the communication system.

[0046] like Figure 4 As shown, in this embodiment, the first conductive layer 21 and the first surface of the substrate 1, where the area is covered by the third conductive layer 23, are provided with an ink layer 7. The third conductive layer 23 has stress holes 9, which can be arranged in an array according to the size of the third conductive layer 23. The multi-band antenna also includes positioning holes 10, the position of which can be adaptively adjusted according to installation requirements. The positioning holes can penetrate the entire antenna structure. Figure 5 As shown, in this embodiment, a third adhesive layer 43 is provided on the second conductive layer 22, excluding the area where the solder joint 3 is located. Release paper 6 is provided on the third adhesive layer 43, and the release paper 6 has a tear-away portion 61 extending beyond the boundary of the third adhesive layer 43. Figure 8As shown, in the utility model, the substrate 1 is PI (polyimide), the first conductive layer 21 and the second conductive layer 22 are both metal layers, which can be copper. The first conductive layer 21 includes at least one first rolled copper layer 211 disposed on the first surface of the substrate 1 and at least one first electroplated copper layer 212 disposed on the first rolled copper layer 211. Similarly, the second conductive layer 22 includes at least one second rolled copper layer 221 disposed on the second surface of the substrate 1 and at least one second electroplated copper layer 222 disposed on the second rolled copper layer 221. The third conductive layer 23 and the solder joint are both gold-nickel alloys. The first adhesive layer 41, the second adhesive layer 42 and the third adhesive layer 43 are double-sided adhesive layers, such as substrate-free double-sided adhesive 3M467.

[0047] Example 1

[0048] like Figure 12 As shown, in this embodiment, the first conductive layer 21 includes a first main body portion 213, a third main body portion 218, and a second main body portion 214 located between the first main body portion 213 and the third main body portion 215. A first connecting portion 219 connects the first main body portion 213 and the second main body portion 214, and a second connecting portion 2110 connects the second main body portion 214 and the third main body portion 215. A first extension segment 216 extends from the first main body portion 213 along a second direction, a second extension segment 217 extends from the second main body portion 214 along a second direction, and a third extension segment 218 extends from the third main body portion 215 along a first direction. The first extension segment 216 can transmit signals in the frequency band range of 5150MHz to 5850MHz, the second extension segment 217 can transmit signals in the frequency band range of 5925MHz to 7125MHz, and the third extension segment 218 can transmit signals in the frequency band range of 2400MHz to 2500MHz. In this embodiment, the first direction is the X-axis, and the second direction is the Y-axis.

[0049] like Figure 16 The diagram shown is a structural diagram of the multi-band antenna in this embodiment, with annotations. The dimension of the first extension segment 216 along the first direction is smaller than the dimension of the first main body 213 along the first direction; the dimension of the second extension segment 217 along the second direction is smaller than the dimension of the second main body 214 along the second direction; and the dimension of the third extension segment 218 along the first direction is smaller than the dimension of the third main body 215 along the first direction. The maximum dimension of the entire antenna along the first direction is 27.53 mm, the maximum dimension along the second direction is 19.83 mm, and the area of ​​the entire antenna is 548.39 mm². 2 The area of ​​existing multi-band antennas is 904.16 mm². 2 .

[0050] like Figure 12As shown, in this embodiment, the first connecting portion 219 includes a first connecting segment 2191, a second connecting segment 2192, a third connecting segment 2193, and a fourth connecting segment 2194 connected in sequence. The first end of the first connecting segment 2191 is connected to the side of the first main body portion 213 near the second main body portion 214 and extends along a first direction. The first end of the second connecting segment 2192 is connected to the second end of the first connecting segment 2191 and extends along a second direction. The first end of the third connecting segment 2193 is connected to the second end of the second connecting segment 2192 and extends in the opposite direction to the first direction. The first end of the fourth connecting segment 2194 is connected to the second end of the third connecting segment 2193 and extends along the second direction. The second end of the fourth connecting segment 2194 is connected to the second main body portion 214. The second connecting portion 2110 includes a fifth connecting segment. The first end of the fifth connecting segment is connected to the side of the second main body portion 214 near the third main body portion 215, and the second end of the fifth connecting segment is connected to the side of the third main body portion 215 away from the third extension segment 218.

[0051] Example 2

[0052] like Figure 14 As shown, in this embodiment, the main body includes a fourth main body 2111 and a fifth main body 2112. A third connecting part 2113 connects the fourth main body 2111 and the fifth main body 2112. A first extension segment 216 extends from the fourth main body 2111 along a second direction. A second extension segment 217 and a third extension segment 217 both extend from the side of the fifth main body 2112 away from the fourth main body 2111 along a first direction. The second extension segment 217 is close to the third connecting part 2113, and the third extension segment 218 is away from the third connecting part 2113. The first extension segment 216 can transmit signals in the frequency band range of 5150MHz to 5850MHz, the second extension segment 217 can transmit signals in the frequency band range of 5925MHz to 7125MHz, and the third extension segment 218 can transmit signals in the frequency band range of 2400MHz to 2500MHz. In this embodiment, the first direction is the X-axis and the second direction is the Y-axis.

[0053] like Figure 17 The diagram shown is a structural diagram of the multi-band antenna in this embodiment, with annotations. The dimension of the first extension segment 216 along the first direction is smaller than the dimension of the fourth main body 2111 along the first direction. The dimensions of the second extension segment 217 and the third extension segment 218 along the second direction are both smaller than the dimension of the fifth main body 2112 along the second direction. The maximum dimension of the entire antenna along the first direction is 27.65 mm, the maximum dimension along the second direction is 19.83 mm, and the area of ​​the entire antenna is approximately 548.39 mm². 2 The area of ​​existing multi-band antennas is 904.16 mm². 2 .

[0054] As Figure 15 shown, the third connecting part 2113 comprises a sixth connecting segment 21131, a seventh connecting segment 21132, an eighth connecting segment 21133 and a ninth connecting segment 21134 connected in sequence, the first end of the sixth connecting segment 21131 is connected with the fourth main body part 2111 near the side of the fifth main body part 2112 and extends along the first direction, the first end of the seventh connecting segment 21132 is connected with the second end of the sixth connecting segment 21131 and extends along the second direction, the first end of the eighth connecting segment 21133 is connected with the second end of the seventh connecting segment 21132 and extends along the opposite direction of the first direction, the first end of the ninth connecting segment 21134 is connected with the second end of the eighth connecting segment 21133 and extends along the second direction, and the second end of the ninth connecting segment 21134 is connected with the fourth main body part 2111.

[0055] As Figure 18 shown, the resonance diagram of the prior art multi-band antenna, the device has certain resonance capacity near the frequency range of 2400MHz-2500MHz and 5150MHz-5850MHz, but the resonance is poor in the frequency band of 5925MHz-7125MHz, and the signal cannot be transmitted stably in the frequency band; as Figure 20 shown, the efficiency diagram in the support frequency band of the prior art multi-band antenna, the average efficiency is-6.95dB in the frequency band of 2400MHz-2500MHz, and the average efficiency is-5.25dB in the frequency band of 5150MHz-5850MHz.

[0056] As Figure 19 shown, the resonance diagram of the multi-band antenna of the utility model, not only can transmit signals in the frequency range of 2400MHz-2500MHz and 5150MHz-5850MHz, but also has good resonance capacity in the frequency range of 5925MHz-7125MHz, and can transmit signals stably in the frequency band; as Figure 21 shown, the efficiency diagram in the support frequency band of the prior art multi-band antenna, in the frequency band range of 5925MHz-7125MHz, the average efficiency is-4.89dB; in the frequency band range of 5150MHz-5850MHz, the average efficiency is-4.64dB, which is improved by 0.61dB compared with the prior art; in the frequency band range of 2400MHz-2500MHz, the average efficiency is-5.12dB, which is improved by 1.83dB compared with the prior art.

[0057] Compared with the multi-band antenna of the prior art, the multi-band antenna in the utility model not only has the signal transmission in a wider frequency band range, but also has higher transmission efficiency in the corresponding frequency band; on the basis of higher transmission efficiency and supporting more frequency bands, the utility model has smaller area compared with the prior art.

[0058] It is obvious for those skilled in the art that the utility model is not limited to the details of the above exemplary embodiments, and the utility model can be implemented in other concrete forms without departing from the spirit or essential characteristics of the utility model. Therefore, the embodiments should be regarded as exemplary and non-restrictive no matter from which point of view, the scope of the utility model is defined by the appended claims rather than the above description, and all changes falling within the meaning and range of the equivalent elements of the claims should be included in the utility model. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0059] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the specification is described in this way only for the sake of clarity, and those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be properly combined to form other embodiments that those skilled in the art can understand.

Claims

1. A multi-band antenna, comprising a substrate, characterized in that, The substrate includes a first surface and a second surface disposed opposite to each other. A first conductive layer is disposed on the first surface. The first conductive layer includes a bent main body portion. A first extension segment extends from a first end of the main body portion along a second direction. A third extension segment extends from a second end of the main body portion along a first direction. A second extension segment extends between the first end and the second end of the main body portion along either the first or the second direction. A second conductive layer is disposed on the second surface.

2. The multi-band antenna according to claim 1, characterized in that, The main body includes a first main body, a third main body, and a second main body located between the first main body and the third main body. A first connecting portion connects the first main body and the second main body, and a second connecting portion connects the second main body and the third main body. A first extension segment extends from the first main body along a second direction, a second extension segment extends from the second main body along a second direction, and a third extension segment extends from the third main body along a first direction. The dimension of the first extension segment along the first direction is smaller than the dimension of the first main body along the first direction, the dimension of the second extension segment along the second direction is smaller than the dimension of the second main body along the second direction, and the dimension of the third extension segment along the first direction is smaller than the dimension of the third main body along the first direction.

3. The multi-band antenna according to claim 2, characterized in that, The first connecting portion includes at least one first connecting segment distributed along a first direction and at least one second connecting segment distributed along a second direction. The dimension of the first connecting segment along the second direction is smaller than the dimension of the first main body portion along the second direction, and the dimension of the second connecting segment along the first direction is smaller than the dimension of the second main body portion along the first direction. The second connecting portion includes at least one fifth connecting segment distributed along the first direction, wherein the dimension of the fifth connecting segment along the second direction is smaller than the dimension of the second main body portion along the second direction and smaller than the dimension of the third main body portion along the second direction.

4. The multi-band antenna according to claim 1, characterized in that, The main body includes a fourth main body and a fifth main body, and a third connecting part is connected between the fourth main body and the fifth main body. The first extension segment extends from the fourth main body along a second direction, and the second extension segment and the third extension segment both extend from the side of the fifth main body away from the second main body along a first direction. The second extension segment is away from the third connecting part, and the third extension segment is close to the third connecting part. The dimension of the first extension segment along the first direction is smaller than the dimension of the fourth main body along the first direction, and the dimensions of the second extension segment and the third extension segment along the second direction are both smaller than the dimension of the fifth main body along the second direction.

5. The multi-band antenna according to claim 4, characterized in that, The third connecting portion includes at least one sixth connecting segment distributed along a first direction and at least one seventh connecting segment distributed along a second direction. The dimension of the sixth connecting segment along the second direction is smaller than the dimension of the first main body portion along the second direction, and the dimension of the seventh connecting segment along the first direction is smaller than the dimension of the second main body portion along the first direction.

6. The multi-band antenna according to claim 2 or 4, characterized in that, The first surface is provided with a third conductive layer covering a portion of the first main body, the third conductive layer being grounded, and the first surface is provided with a cover film covering a portion of the first conductive layer, the cover film being located in the area of ​​the first surface not covered by the third conductive layer.

7. The multi-band antenna according to claim 1, characterized in that, The second conductive layer has spaced feedback points and grounding points.

8. The multi-band antenna according to claim 7, characterized in that, A first adhesive layer is provided on the second surface. The first adhesive layer is located on a portion of the second conductive layer and covers the area of ​​the second conductive layer except for the feedback point and the ground point.

9. The multi-band antenna according to claim 8, characterized in that, The first adhesive layer, the cover feedback point, and the grounding point are covered with release paper, which has a tear-away portion extending beyond the edge of the first adhesive layer.

10. The multi-band antenna according to claim 1, characterized in that, A second adhesive layer is provided between the first conductive layer and the substrate. The first conductive layer includes a first calendered layer close to the first double-sided adhesive layer and a first electroplated layer away from the first double-sided adhesive layer. A third adhesive layer is provided between the second conductive layer and the substrate. The second conductive layer includes a second calendered layer close to the third adhesive layer and a second electroplated layer away from the third adhesive layer.

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