What are LMR 900 Coaxial Cables?

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- everything RF

Mar 28, 2023

LMR 900 Coaxial Cables are cables that are designed for carrying high frequency RF signals for wireless communication system and other antenna applications.

LMR 900 Coaxial Cable

LMR 900 Coaxial Cable Construction

The LMR 900 is a 50-ohm, low-loss, flexible, double-shielded coaxial cable with an overall diameter of 0. 870 inches, developed by Times Microwave Systems, and has a voltage rating of up to 5000 VDC. It has an internal bare copper tube conductor (carrying the electrical signal), which is enclosed by an insulation layer made of Foam Polyethylene (Foam PE). The insulation layer is then completely enclosed by two shield layers. The first shielding layer is made of aluminum tape, and the outer shield is made of a tinned copper braid. The shields form an outer conductor, which also provides protection from electromagnetic interference (EMI). Finally, the structure is covered with an outermost layer - called a jacket - made of Polyethylene (PE)/ Flame retardant PE (FRPE).  The jacket protects the cable core from mechanical, moisture, chemical issues, and environmental factors.

The LMR 900 cable exhibits capacitance of approximately 23.4 pF/ft (76.6 pF/m) and signal attenuation of around 1.7 dB/100ft at 900 MHz (signal attenuation of the cable depending on the frequency) and has a velocity of propagation of 87 %. It has a center conductor measuring 0.262 inches (6.65 mm) in diameter and an insulation layer measuring 0.680 inches (17.27 mm) in diameter. The double shielding structure of the LMR 900 coaxial cable offers RF shielding of more than 90 dB. 

The flexible, low-loss LMR 900 cable is ideal for medium antenna feeder runs (no jumpers required), jumper assemblies for 1-5/8” & 2-1/4” feeders,  and any application (e.g., WLL, GPS, LMR, WLAN, WISP, WiMAX, SCADA, Mobile Antennas) requiring an easily routed,  low loss RF cable. 

Key Specifications of LMR 900 Coaxial Cables


Typical Value

Overall Diameter (inch)


Characteristic Impedance (Zo)

50 ohms

Maximum Voltage Rating (VDC)

5000 V

Cable Capacitance (pF/ft)


Inductance (µH/ft)


Attenuation (dB/100 ft, @ 900 MHz)



Foam Polyethylene (Foam PE)

Minimum Bend Radius (inch), installation


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