RF coaxial cables are cylindrical transmission lines consisting of concentric conductors separated by dielectric materials. They enable efficient transfer of high-frequency electrical signals (typically 1 MHz to 110 GHz) with minimal interference, making them critical components in telecommunications, broadcasting, aerospace, and test equipment. Their shielded structure ensures signal integrity in noisy environments.
2. Main Types and Functional Classification
Type
Key Features
Applications
Rigid Coaxial Cable
Metallic outer conductor, fixed geometry
Test labs, high-power transmitters
Semi-Rigid Cable
Formable but non-flexing, excellent shielding
Microwave systems, aerospace
Flexible Coaxial Cable
Braided shield, bendable
General-purpose communication systems
Low-Loss Foam Dielectric
PE/PTFE dielectric, reduced attenuation
5G infrastructure, satellite links
3. Structure and Composition
Typical construction includes:
Center Conductor: Solid/stranded copper/aluminum for signal transmission
Dielectric Insulator: Polyethylene (PE) or PTFE foam maintaining uniform impedance
Shielding Layer: Braided copper/aluminum with 85-95% coverage (single/double layers)
Outer Jacket: PVC/PE for mechanical/environmental protection
Critical dimensions determine characteristic impedance (commonly 50 for data/75 for video).
4. Key Technical Parameters
Parameter
Description
Importance
Characteristic Impedance
Matched load resistance (50/75 )
Minimizes signal reflection
Attenuation (dB/100m)
Signal loss per unit length
Determines transmission distance
Frequency Range
Operational bandwidth (e.g., 0-18GHz)
Limits application scope
VSWR
Voltage Standing Wave Ratio
Measures impedance matching quality
Power Handling
Max RF power capacity
Prevents dielectric breakdown
5. Application Fields
Telecommunications: 5G base stations, fiber-wireless systems
Broadcasting: TV antenna feeds, studio equipment
Aerospace: Radar systems, avionics
Test & Measurement: Oscilloscope probes, signal analyzers