1. Overview
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
- Industrial IoT: Wireless sensor networks
6. Leading Manufacturers
| Manufacturer | Key Products |
| Amphenol Corporation | SUCOFLEX 104, 106 series |
| TE Connectivity | Radiation-resistant RG-58 |
| HUBER+SUHNER | RF flexible cables (SST series) |
| CommScope | Heliax FSJ1-50A |
| Southwest Microwave | 832 Series semi-rigid |
7. Selection Guidelines
Key considerations:
- Match impedance to system requirements
- Verify frequency/attenuation specifications
- Environmental factors (temperature, UV resistance)
- Mechanical requirements (flexure life, bending radius)
- Connector compatibility (SMA, N-Type, etc.)
Example: 5G massive MIMO deployment requires low-PIM (Passive Intermodulation) cables with <0.1dB/100m loss at 3.5GHz.
8. Industry Trends
- High-Frequency Demand: Development of 110GHz+ cables for 6G research
- Weight Reduction: Composite materials in aerospace applications
- Green Manufacturing: Halogen-free jacket materials adoption
- Smart Cables: Embedded sensors for condition monitoring
- Standardization: 5G NR band-specific cable specifications