Coaxial cables are cylindrical cables composed of an inner metal conductor surrounded by a tubular insulating dielectric material, which in turn is surrounded by a protective tubular conducting shield and covered by an overall jacket. The term “coaxial” refers to the shared geometric axis of the tubular inner conductor and outer conducting shield. In contrast, a simple shielded cable is comprised of braided or spiral-wound strands within an insulating jacket.
While traditional shielded cables are used to transmit lower frequency signals, coaxial cables function as transmission lines, conducting alternating currents of radio frequency signals. With superior transmission and reception capabilities, coaxial cables are commonly used for broadband Ethernet, cable television, and commercial radio.
What Are The Different Types of Coaxial Cables?
Coaxial cables differ in design depending on their end use. Shorter cables often appear in household applications such as AV systems or personal Ethernet connections, while longer cables can connect entire radio and television networks or long-distance phones. Micro/mini cables are also frequently used in various consumer, military, aerospace, and medical devices.
Below are some of the most common coaxial cable types and the applications they support.
Hardline
Polyethylene Dielectric CoaxConstructed using copper, silver, aluminum, or steel for the center conductor and one of these materials for a shield, these thick cables (≥ ½-inch diameter) are used for high-strength transmission in applications such as military signals or broadcasting radio between a ground-level transmitter and an antenna or aerial receiver. Hardline cables may contain a dielectric buffer such as polyethylene foam or pressurized nitrogen to prevent arcing and moisture contamination. Shield materials vary from piping to rigid or corrugated tubing.
Radiating
Also called “leaky cables,” radiating cables have a similar structure to hardline but with the addition of slots cut into the shield, tuned to specific wavelengths or radio frequencies. By allowing a pre-determined amount of “leakage” between the transmitter and the receiver, these cables can be implemented in locations where antennas are not feasible.
Twin Axial Coax CableTwinaxial
Also known as “Twinax,” these cables share the same structure as coaxial cables but have two central conductors instead of one. They are used for high-speed, short-range signaling applications, such as network hardware with SFP+ interfaces.
Triaxial
Triaxial Coax CableAlso known as “Triax,” these cables share the same structure as coaxial cables but have an added layer of insulation and a second conducting sheath. These cables are more expensive than standard coaxial cables but provide greater bandwidth and less interference for television production or applications exposed to interference-inducing electromagnetic forces.
Semi-Rigid
With a PTFE-supported dielectric and a shield made of a solid conductor instead of stranded wires, semi-rigid coaxial cables offer better dielectric properties for enhanced performance at high frequencies. Compared to rigid cables, however, semi-rigid lines are limited in size and frequency transmission.
Rigid Line
Rigid coaxial cables contain two copper tubes and a PTFE dielectric buffer supported at both ends of the cable as well as at various intervals throughout which prevents bends. Ranging from ⅞-inch to 8³/₁₆-inch diameters, rigid lines are much bigger than semi-rigid cables and have the power capacities to operate TV and FM frequencies with multi-channel transmission.
This article comes from conwire edit released