Why Triaxial Cables Excel Beyond Standard RG Coaxial Cables: The Power of the Extra Shield

In high-frequency RF communication, sensitive industrial testing, and high-precision signal processing, electromagnetic interference (EMI) and radio frequency interference (RFI) remain persistent challenges for design engineers. While standard RG coaxial cables serve general RF applications reliably, demanding environments require superior shielding performance. This is where Triaxial Cables make a significant difference. By introducing a second, isolated copper shield into the classic coaxial architecture, triaxial cables deliver enhanced signal protection and noise isolation.

To understand why triaxial cables outperform standard coaxial cables, it helps to look at how their structural designs handle interference and ground noise.

A standard RG coax features a single center conductor, a dielectric layer, a single braided shield (serving simultaneously as the signal return and protective barrier), and an outer jacket. Because the braid carries both the return signal and external noise currents, high EMI can lead to ground loop hum, crosstalk, and measurement inaccuracies.

A triaxial cable adds a second conductive braid shield separated by an additional inner insulation layer:

• Center Conductor: Carries the primary signal.

• Inner Braid Shield: Serves as the dedicated, isolated signal return line.

• Outer Braid Shield: Functions as a dedicated ground shield, draining external EMI/RFI before it can penetrate the inner transmission core.

1. Maximum EMI/RFI Rejection: The outer shield acts as a physical Faraday cage. External electrical noise is absorbed and shunted to ground, keeping the internal signal pathway completely untouched.

2. Elimination of Ground Loop Interference: By physically decoupling the ground shield from the inner signal return path, triaxial cables eliminate common ground loops that plague single-shield RG coaxes.

3. Ultra-Low Leakage Current: In precision testing and high-sensitivity measurement systems, triaxial cables reduce noise floors to picoamp or femtoamp levels, enabling accurate readings without signal degradation.

Choosing the correct triaxial model often comes down to matching system space constraints and impedance requirements. Below is our featured TRX Series triaxial lineup, highlighting outer dimensions for convenient model comparison:

When precision, low noise floor, and complete EMI immunity are critical to your system's performance, stepping up from standard RG coaxes to a dedicated TRX Triaxial Cable ensures maximum signal fidelity.

Explore our full line of customizable triaxial cable solutions or consult our technical team today to select the optimal cable dimensions and parameters for your project.