What are RG405 Coaxial Cables?

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- everything RF

Feb 1, 2023

RG405 Coaxial Cables are a type of cable used for carrying radio frequency (RF) signals while ensuring high signal integrity and low level of signal attenuation. They are suitable for testing and telecommunication systems.


RG405/U Cable Construction

The RG405/U is a 50-ohm coaxial cable with an overall diameter of 0.086 inches and a voltage rating of up to 1500 Vrms. It has an internal silver-coated copper-clad steel (SCCS) conductor (carrying the electrical signal), which is enclosed by an insulation layer made of Polytetrafluoroethylene (PTFE). The insulation layer is then completely enclosed by a bare copper tube (BC Tube) shield that forms the outer conductor and also provides shielding against electromagnetic interference (EMI). 

The RG405/U cable exhibits capacitance of approximately 29.4 pF/ft (96.5 pF/m), and signal attenuation of around 13.0 dB/100 ft at 400 MHz (signal attenuation of the cable depending on the frequency). It has a center conductor measuring 0.0201 inches (0.5105 mm) in diameter and an insulation layer measuring 0.066 inches (1.67 mm) in diameter. This cable is ideal for use in direct burial applications, test equipment port jumpers, and other applications. It has an operating temperature of -55˚C to + 100˚C.

Key Specifications of RG405//U Coaxial Cables


Typical Value

Overall Diameter (inch)


Characteristic Impedance (Zo)

50 ohms

Maximum Voltage Rating (RMS)

1500 V

Cable Capacitance (pF/ft)


Attenuation (dB/100 ft, @ 400 MHz)



Polytetrafluoroethylene (PTFE)

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