What Is a Coaxial Cable?

The Four-Layer Structure Behind Every Coaxial Cable

Every coaxial cable, whether it comes from a small workshop or a certified China coaxial cable factory, follows the same basic geometry. This layered design is exactly what separates a coaxial cable from an ordinary twisted-pair or single-core wire, and it is the reason engineers trust it for frequency-sensitive circuits.

• Center conductor: A single solid wire or a stranded bundle, usually bare copper, silver-plated copper, or nickel-plated copper, that physically carries the electrical signal.
• Dielectric insulator: A layer of PE, PTFE, or FEP surrounding the conductor. Its material and thickness set the cable's characteristic impedance, typically 50 ohms or 75 ohms.
• Shielding layer: A braided copper mesh, aluminum foil, or a combination of both, wrapped around the dielectric to block outside noise and stop the signal from leaking outward.
• Outer jacket: A protective sleeve, often PVC, FEP, or silicone, that resists abrasion, moisture, UV exposure, and in industrial-grade cables, extreme heat.

Why Coaxial Cables Transmit Signals So Cleanly

Because the shielding layer surrounds the center conductor on every side, electromagnetic fields stay trapped inside the cable instead of radiating outward or leaking in from nearby motors, transformers, or radio sources. This geometry keeps the characteristic impedance constant along the full cable length, which matters because any mismatch in impedance causes signal reflection, echo, or data errors.

A well-built industrial coaxial cable with 90 to 95 percent braid coverage plus a foil layer can achieve shielding effectiveness above 90dB, meaning less than a fraction of a percent of outside noise reaches the signal path. This is why coaxial cable stays the preferred medium for cable television, base station feeders, GPS antennas, and vibration sensors on factory floors where dozens of motors run simultaneously.

Coaxial Cable Types Compared by Dielectric Material

Not all coaxial cable performs the same under heat or chemical exposure. The table below compares the three dielectric families most commonly requested from a coaxial cable supplier.

Teflon-based coaxial cable costs more upfront, but its stable dielectric constant across a wide temperature range is what keeps impedance from drifting, which is critical for any custom coaxial cable built for aerospace or medical equipment.

50 Ohm or 75 Ohm: Choosing the Right Impedance

Impedance selection is one of the most common questions buyers bring to a coaxial cable manufacturer, and getting it wrong causes measurable signal loss even if every other spec looks correct.

Sourcing From a China Coaxial Cable Supplier

Most industrial buyers no longer shop for a single spec sheet; they look for a China coaxial cable supplier able to support R&D, custom construction, and repeat wholesale volume from one production line. A dependable China coaxial cable manufacturer typically brings together three things: material sourcing, in-house testing, and documented certification.

As a China coaxial cable factory operating since 1994, our production covers eight major cable series and close to a thousand specifications, with conductor cross-sections up to 400mm², voltage ratings up to 100kV, and temperature ratings spanning -65C to +1200C. Every meter of coaxial cable produced goes through 100 percent time-domain reflectometry testing to confirm there are no impedance mismatches along the run, and the facility holds ISO9001, UL, CE, and CCC certification.

Custom Coaxial Cable vs. Wholesale Coaxial Cable

Buyers generally fall into two groups, and it helps to know which one describes your project before contacting a coaxial cable supplier.

• Custom coaxial cable supplier route: Best when the application needs a non-standard outer diameter, a specific shielding ratio, a non-magnetic build for MRI equipment, or a jacket compound rated for chemical exposure. A custom coaxial cable factory will typically request the frequency range, impedance, and environmental conditions before quoting.
• Wholesale coaxial cable supplier route: Best for standard RG or SFF series cable purchased in bulk for telecom rollouts, security camera installation, or OEM assembly. A wholesale coaxial cable factory can usually hold pricing steady on volume orders of established part numbers.

Many buyers use both paths at once: a custom prototype is developed and validated first, then the same design moves into wholesale coaxial cable production once the specification is locked.

Where Coaxial Cable Is Used Today

Coaxial cable applications extend well beyond home television. Industrial-grade coaxial cable from a specialized manufacturer is engineered for demanding, high-consequence environments.

• Aerospace and avionics: GPS, radar, and communication links where weight and resistance to extreme cold and heat are non-negotiable.
• Medical imaging: Non-magnetic coaxial cable transmits high-resolution data inside MRI and X-ray systems without distorting the magnetic field.
• Industrial sensors: Vibration and pressure sensors on turbines and petrochemical equipment rely on stable signal transmission despite constant heat and vibration.
• Telecommunications: Base stations and microwave links depend on low-loss coaxial cable for long-distance signal runs.
• Security and broadcast: CCTV networks and TV distribution systems use 75-ohm coaxial cable for consistent picture quality over hundreds of meters.