1.High frequency skin effect of electrical conductor
High frequency signal will transfer on the surface of conductor when the current passes the conductor, bringing the skin effect; while current in the core is less, or even non. Depth of current on the surface of conductor can be showed by ¦Ä. Following formula can be used to count depth of copper conductor:
¦Ä=67/f 1/2(mm), f stands for frequency £¨Hz£©
Thinnest copper layer thickness of coaxial cable and skin effect depth while transferring 5 to 100MHz signal as follows:
Diameter of copper cladding aluminum wire mm |
Thickness of thinnest copper layer mm |
Depth of skin effect mm |
10A 10H |
15A 15H |
5MHz |
15MHz |
100MHz |
2.15 |
0.038 |
0.054 |
0.02996 |
0.02119 |
0.0067 |
2.77 |
0.048 |
0.069 |
3.15 |
0.055 |
0.079 |
2.Performance of copper cladding aluminum wire and pure copper lead £º
| Index |
Copper Cladding Aluminum CCA-15 |
Pure Copper Wire |
| Hard |
Soft |
Hard |
Soft |
| Density£¨g/cm32£© |
3.63 |
8.89 |
| Conductivity (¦¸mm2/m) |
0.02676 |
0.017421 |
| Length Ratio£¨same weight and wire size£© |
2.5 |
1 |
| Elongation£¨%£© |
£¾1.0 |
£¾15 |
0.2~0.5 |
30~45 |
3.Contrast between bimetal wire of cladding welding technique and electroplating method
Index |
Cladding welding technique |
Electroplating method |
Material of Copper Layer |
High purity, good airproofing performance, loose copper layer, with impurity |
Homogeneous degree of copper layer |
Combining method of two metals |
metallurgy combination among atoms with core wire is firm and wearable |
copper ion in electrolyte is attached on surface of core wire not firmly and easily to fall. |
Homogeneous degree of copper layer |
The copper layer is distributed evenly along the circle and vertical direction with good coaxiality; |
while thickness of copper layer is not equal. |
pollution |
No |
electroplating solution can pollute the environment seriously and is harmful to humans, therefore it is forbidden to use gradually. |
4.Model of coaxial cable of CATV and spec of related bimetal internal conductor:
Model of coaxial cable of CATV |
Materials Of Internal Conductor |
Wire size£¨mm£© |
Nominal |
Mini |
Max |
SYWV-75-9 SYWLY-75-9 SYWY-75-9 |
Copper cladding aluminum wire |
2.15 |
2.12 |
2.18 |
SYWLY-75-12 |
Copper cladding aluminum wire |
2.77 |
2.74 |
2.8 |
Resource: SJ/T11138-1997 Coaxial cable with physically-foamed polyethylene insulation for use in cabled distribution systems
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