Coaxial Cable Specifications and Technical Data Sheets
Coaxial cables are crucial for transmitting high-frequency electrical signals with minimal interference. This article offers an overview of their specifications and technical data.
1. Structure of Coaxial Cables
A coaxial cable comprises four main parts:
- Inner Conductor: Usually made of copper, it carries the electrical signal.
- Dielectric Insulation: Materials like polyethylene isolate the inner conductor and prevent signal leakage.
- Outer Conductor (Shield): It can be braided wire mesh or a solid tube, shielding against EMI and serving as a return path for current.
- Outer Jacket: Made of PVC or PU, it protects the cable from physical damage and environmental factors.
2. Key Specifications
2.1 Characteristic Impedance
Measured in ohms, common values are 50 Ω (RF applications), 75 Ω (video and CATV), and 93 Ω (specific data systems).
2.2 Attenuation
Signal loss along the cable, measured in dB/m, is affected by frequency, length, and cable construction.
2.3 Capacitance and Inductance
Capacitance (pF/m) impacts signal speed and impedance; inductance (H/m) influences impedance and signal – carrying capacity.
2.4 Maximum Voltage Rating
Determined by the dielectric and construction, it indicates the highest safe voltage the cable can carry.
3. Technical Data Sheets
They detail a cable’s performance:
- General Information: Manufacturer, model number, and application.
- Physical Specifications: Overall diameter, inner/outer conductor dimensions.
- Electrical Specifications: Impedance, attenuation at different frequencies, and VSWR.
- Environmental Specifications: Operating temperature range, humidity, and flame resistance.
4. Types of Coaxial Cables
- Rigid Coaxial Cables: Solid outer conductor, used in high-power RF, with low loss but low flexibility.
- Flexible Coaxial Cables: Braided outer conductor, common in consumer electronics, more flexible but higher attenuation.
- Semi – Rigid Coaxial Cables: Balance rigidity and flexibility, used in aerospace and military.
- Triaxial Cables: Extra shielding layer, for applications requiring high EMI protection.
5. Applications of Coaxial Cables
Used in telecommunications (telephone and cellular networks), broadcasting (CATV and radio), data transmission (Ethernet and high – speed links), and industrial/military systems.
6. Choosing the Right Coaxial Cable
Consider application requirements, cable length, environmental conditions, and cost – effectiveness when selecting a coaxial cable.