Coaxial cable, commonly referred to as “coax,” represents one of the most versatile and reliable transmission mediums in modern telecommunications and networking infrastructure. As we enter 2025, coaxial technology continues to evolve while maintaining its essential role in critical applications ranging from high-definition video distribution to advanced RF communications systems.
This comprehensive guide explores the technical specifications, classification standards, application scenarios, and selection criteria for coaxial cables, providing network engineers, cable installers, and technical decision-makers with the knowledge needed to make informed choices.
Fundamental Construction and Components
Every coaxial cable incorporates a precise layered structure that ensures signal integrity and electromagnetic interference (EMI) protection:
- Center Conductor: Typically copper or copper-clad steel (CCS), ranging from 14 AWG to 22 AWG depending on application
- Dielectric Insulator: Usually polyethylene (solid, foam, or gas-injected) determining propagation velocity and capacitance
- Shielding Layer(s): Aluminum foil and/or copper braid providing electromagnetic isolation
- Outer Jacket: Weather-resistant PVC, LSZH (Low Smoke Zero Halogen), or PE (polyethylene) for environmental protection
The concentric construction creates a controlled impedance path, typically 75Ω for video/broadcast or 50Ω for RF/wireless applications, allowing signals to propagate with minimal reflection and loss.
For detailed explanations of the physical construction, visit our article on What Is Coaxial Cable.
Coaxial Cable Standards and Classification Systems
RG Classification System
The Radio Guide (RG) designation system originated during World War II when the U.S. military standardized cable specifications. Today, these specifications are maintained through the MIL-DTL-17 standard. Common RG types include:
| Cable Type | Impedance (Ω) | Center Conductor | Applications | Typical Max Distance |
|---|---|---|---|---|
| RG59 | 75 | 20 AWG CCS | CCTV, analog video | 230 ft / 70 m |
| RG6 | 75 | 18 AWG CCS | HDTV, satellite, broadband | 300 ft / 91 m |
| RG11 | 75 | 14 AWG Cu | Long CATV runs, campus installations | 500 ft / 152 m |
| RG8 | 50 | 13 AWG Cu | Amateur radio, RF transmission | 270 ft / 82 m |
Learn more about the high-performance capabilities of RG11 in our detailed RG11 Coaxial Cable Guide.
JIS Standard Classification
Japanese Industrial Standards (JIS) provide another classification system widely used in international markets. The JIS standard uses a systematic naming convention where each character denotes specific properties:
S-5C-2V
│ │ │ │
│ │ │ └─ V: Single braid, vinyl jacketed
│ │ └─── 2: Polyethylene dielectric
│ └───── C: 75Ω impedance (for video applications)
└─────── S: BS/CS broadcast compatibleFor reference, the JIS cable thickness guidelines:
| Cable Type | Outer Diameter | Attenuation (10MHz) |
|---|---|---|
| 1.5C/1.5D | 2.9-3.4 mm | 82-106 dB/km |
| 3C/3D | 5.3-6.5 mm | 35-47 dB/km |
| 5C/5D | 7.3-8.3 mm | 25-30 dB/km |
| 7C | 10.0-10.4 mm | 20-22 dB/km |
| 10D | 13.1-14.7 mm | 14 dB/km |
Technical Specifications and Performance Metrics
Impedance and Return Loss
Impedance represents the opposition to signal flow in the cable, measured in ohms (Ω). Coaxial systems rely on consistent impedance throughout the entire transmission path to prevent signal reflections.
Return Loss (RL) and Voltage Standing Wave Ratio (VSWR) measure how much signal reflects back due to impedance mismatches. Per IEC 61196-1-112:2025, high-quality coaxial cables should maintain:
- RL > 26 dB at 5-1000 MHz
- RL > 22 dB at 1000-2000 MHz
- RL > 20 dB at 2000-3000 MHz
Attenuation and Bandwidth
Signal loss in coaxial cables increases with frequency and distance. The table below shows typical attenuation values for various cable types:
| Cable Type | Attenuation at 100 MHz (dB/100m) | Attenuation at 1 GHz (dB/100m) | Attenuation at 3 GHz (dB/100m) |
|---|---|---|---|
| RG59 | 9.8 | 31.4 | 59.7 |
| RG6 Standard | 6.9 | 22.6 | 42.0 |
| RG6 Quad | 6.6 | 21.3 | 39.8 |
| RG11 | 4.9 | 16.1 | 31.2 |
Shielding Effectiveness
Measured in dB, shielding effectiveness indicates a cable’s ability to prevent signal leakage and reject external interference:
| Shield Type | Construction | Effectiveness (30-1000 MHz) | Best For |
|---|---|---|---|
| Single Shield | Foil (100% coverage) | 60-70 dB | Basic indoor applications |
| Dual Shield | Foil + Braid (60-95%) | 70-90 dB | Residential video/data |
| Tri-Shield | Foil + Braid + Foil | 90-110 dB | High EMI environments |
| Quad-Shield | Foil + Braid + Foil + Braid | >110 dB | Industrial/critical infrastructure |
For a comprehensive comparison of different shielding options, see our guide on RG6 vs RG6 Tri-Shield vs RG6 Quad-Shield.
Major Applications and Implementation Scenarios
Broadband Internet and Cable Television
Cable companies utilize a Hybrid Fiber-Coaxial (HFC) network architecture where fiber optic cables connect to neighborhood nodes, then distribute signals via coaxial cable to individual premises. For optimal residential broadband performance:
- Drop Line (Provider to Home): RG11 or flooded RG6 (weather-resistant)
- Internal Distribution: RG6 standard or quad-shield depending on EMI environment
- Modem Connection: RG6 with proper compression F-connectors
Satellite TV Distribution
Satellite systems operate at higher frequencies (up to 3 GHz) than traditional cable TV, requiring:
- Low-loss RG6 Quad-Shield for runs from dish to receiver
- Solid copper or high-quality CCS center conductor
- Weather-sealed compression connectors for outdoor connections
Learn more about copper conductor options in our Copper-Clad Steel vs Solid Copper Coax article.
CCTV and Security Systems
Video surveillance systems benefit from coaxial infrastructure due to:
- Direct analog HD support (HD-CVI, HD-TVI, AHD) over existing RG59 infrastructure
- Power-over-Coax (PoC) technology for single-cable power and video
- No IP configuration requirements for basic systems
- Maximum cable distances before signal degradation:
- RG59: up to 700 ft (213 m) for 720p, 450 ft (137 m) for 1080p
- RG6: up to 1,000 ft (305 m) for 720p, 650 ft (198 m) for 1080p
- RG11: up to 1,500 ft (457 m) for 720p, 1,000 ft (305 m) for 1080p
RF Communications
Professional RF applications demand precise impedance matching and low-loss performance:
- Amateur Radio: 50Ω RG8/LMR-400 cables for transmitter-to-antenna connections
- Wireless Backhaul: Low-loss cables like LDF4-50A Heliax for tower installations
- Test Equipment: Phase-stable, temperature-compensated cables for precision measurements
Selection Criteria and Decision Framework
Decision Flow Process
When selecting coaxial cable, consider these factors in sequence:
- Frequency Range: Higher frequencies require better-quality cables with superior shielding
- Distance Requirements: Longer runs need lower-attenuation cables (larger gauge)
- Environmental Conditions: Indoor/outdoor, UV exposure, temperature extremes
- EMI Environment: Higher interference requires better shielding
- Mechanical Stress: Bend radius, pull tension, and installation method
- Budget Constraints: Balance initial cost against long-term performance
Environmental Considerations
| Environment | Recommended Features | Example Cable Types |
|---|---|---|
| Indoor Residential | Basic flame rating, standard jacket | RG6, RG59 |
| Plenum Spaces | CMP rating, low-smoke zero-halogen (LSZH) | Plenum-rated RG6 |
| Direct Burial | Flooded core, PE jacket, moisture blocking | Flooded RG11, Direct Burial RG6 |
| Aerial Installation | UV-resistant jacket, messenger wire | Messenger RG6, CATV Aerial |
| Industrial | Oil-resistant, high-temp rating, armored | Armored RG6, Industrial RG11 |
Installation Best Practices
Proper installation significantly impacts the performance and longevity of coaxial systems:
Cable Preparation and Termination
- Cut the cable squarely using appropriate cable cutters
- Strip the outer jacket, shield, and dielectric using the correct dimensions:
- F-connector: 1/4″ exposed center conductor
- BNC/RCA: Specific to connector manufacturer requirements
- Avoid nicking the center conductor or shield
- Use the proper compression or crimp tool designed for your connector type
For detailed step-by-step instructions, visit our guide on How To Terminate The Coaxial Cable and How to Crimp Coaxial Cable.
Installation Techniques
- Bend Radius: Maintain minimum 10× cable diameter to prevent internal damage
- Support Method: Use appropriate clips/ties every 12-18″ horizontally, 4-6′ vertically
- Proximity to Power: Cross power cables at 90° angles; maintain minimum 6″ parallel separation
- Signal Boosters: Install amplifiers near the source for best signal-to-noise ratio
- Weatherproofing: Use self-amalgamating tape and/or UV-resistant boot covers for outdoor connections
Discover more installation techniques in our comprehensive Coaxial Cable Installation Guide.
Troubleshooting Common Issues
| Symptom | Possible Causes | Solution |
|---|---|---|
| No signal | Connector not properly terminated, cable break | Check continuity with multimeter, re-terminate if necessary |
| Intermittent signal | Loose connection, water ingress, physical damage | Inspect connectors, replace damaged sections |
| Pixelation/artifacts | Signal too weak, excessive splitters, poor quality connectors | Reduce splitter count, check signal level with meter, consider amplifier |
| Interference/noise | Insufficient shielding, ground loops, proximity to EMI sources | Upgrade to better shielded cable, check grounding, relocate cable |
Learn more about preventing cable failures in Why Coax Cables Fail.
Future Trends in Coaxial Technology
As we progress through 2025, several developments are shaping the coaxial cable industry:
- Higher Frequency Support: Extended bandwidth cables supporting frequencies up to 6 GHz for advanced applications
- Improved Dielectric Materials: Lower-loss dielectrics for reduced attenuation at high frequencies
- Hybrid Cable Solutions: Combined fiber optic/coaxial cables for transitional infrastructure
- Advanced Shielding: Nano-materials and enhanced manufacturing techniques for superior EMI protection
- Smart Diagnostics: Embedded monitoring capabilities for enterprise-level cable management
Conclusion
Coaxial cable remains an essential component of modern telecommunications infrastructure despite advancements in fiber optic technology. Its unique shielding properties, standardized connectors, and cost-effective implementation continue to make it the ideal choice for many applications.
By understanding the technical specifications, classification systems, and selection criteria outlined in this guide, you can make informed decisions about which coaxial cable best suits your specific requirements. Remember that proper cable selection combined with correct installation techniques will ensure optimal performance and longevity of your communications system.
For more information on specific coaxial cable types and applications, explore our detailed guides on Types of Coaxial Cables and How They Are Specified.
