Coaxial cable details

An introduction to coaxial cables

1. General application and performance

Coaxial cables are designed to provide excellent high bandwidth properties, low loss signal attenuation and prevent signal leakage or interference in signal transmission.

Typical applications of KCI coaxial cables include radio, community antenna television, prime antenna television, closed-circuit television and widely used in local area networks (LANS), instrument control systems, detector areas, etc.

Choosing the best coaxial cable for a new application requires an understanding of the application and the wide range of cables.
The best choice can only be made by carefully evaluating the performance and cost trade-offs.
Our deep expertise in all aspects of coaxial cable technology can help you make the best choice for your application.

In selecting the best coaxial cable for an application, the cable characteristics listed below should be considered. The following sections provide detailed discussions of each feature.

1- characteristic impedance (also impedance uniformity)
2- Attenuation (also uniformity and stability of attenuation)
3- Protector
4- Capacity
5- Release speed
6- Flexibility
7- Cable resistance, environmental resistance

2. Making cables

Construction details

1-1 Internal conductor (materials):

plain annealed copper, copper clad steel,
Tin annealed copper, silver plated copper

1-2 internal conductors:

2- Dielectric (materials):

3- Braid, shield (materials):

4- Jacket (materials):

4. Weakening screening

Attenuation is the screening capacity of the outer conductor of a coaxial cable to reduce the strength of electromagnetic signals coming from the external environment.
The interference signal hits the outer conductor of the screening and is weakened in passing through the conductive layer to such an extent that the more the thickness and coverage of the screening, the more it is intensified.

This parameter tells us how much the interference signal has been reduced by passing through the outer conductor of the cable. For example, a cable with a screening efficiency of 75 dB provides a measurable attenuation of approximately 5600 times.
With an effectiveness of 90 dB, the reduction is 31,600 times. Higher efficiency cables (triple and 100dB) can reduce interference more than 100,000 times.

Required data coaxial cables
Standard requirements and tests in accordance with JIS C -3501

General requirements

Item		Characteristics
Electrical resistance of inner conductor		Not more than the value in JIS C3005
Dielectric strength		To withstand the test voltage of related Table for 1 minute
Insulation resistance		Not less than 1000 Mohm x kM
Capacitance		Within the range given in Related Table
Characteristic impedance	50 Ohm type	50 ± 2 Ohm
	75 Ohm type	75 ± 3 Ohm
Velocity ratio		for Solid PE (66 +/- 2 %)
Attenuation		Maximum value shall be not more than 115 % of the standard value given in related Table

Mechanical and Thermal Requirements

Item			Characteristics
Tension of insulation and sheath	Insulation	Tensile strength	10 MPa (1.02 kgf/mm2) min.
	Insulation	Elongation	400 % min.
	Sheath	Tensile strength	10 MPa (1.02 kgf/mm2) min.
	Sheath	Elongation	200 % min.
Heating (Accelerated Aging Test)	Insulation	Tensile strength	Not less than 80 % of the value before heating
	Insulation	Elongation	Not less than 65 % of the value before heating
	Sheath	Tensile strength	Not less than 80 % of the value before heating
	Sheath	Elongation	Not less than 80 % of the value before heating
Dielectric loss tangent			6 x 10-4 max.
Dielectric constant			2.2 to 2.5
Heat shrinkage			± 10 %
Cold bend			No crack nor split shall appear