LMR400

LMR400 is a 50-ohm low-loss RF coaxial cable manufactured by Times Microwave Systems. It features a solid polytetrafluoroethylene (PTFE) dielectric, a copper center conductor, and a double shield (foil and braid) to provide high shielding effectiveness. The outer jacket is often a UV-resistant fluoropolymer or PVC compound depending on variant, making it suitable for indoor and outdoor installations.

The cable is designed to offer lower attenuation than many general-purpose coaxials, enabling longer run lengths between devices with less signal loss. Its construction provides good flexibility for field routing while maintaining mechanical durability. The velocity factor is high, typically around 0.8 to 0.84, reflecting the PTFE dielectric.

LMR400 is used in a variety of RF applications, including wireless base stations, point-to-point wireless links, antenna feedlines, and other 50-ohm systems requiring reliable performance. It is compatible with standard RF connectors, with N-type and SMA types commonly used, and connectors can be selected based on impedance, frequency, and environmental requirements.

The LMR family covers several low-loss cables with differing diameters and flexibilities; LMR400 sits between the smaller LMR-200/195 and the larger higher-performance variants. In practice, LMR400 offers a balance of attenuation, mechanical flexibility, and outdoor durability suitable for commercial and industrial deployments.