WHAT is lmr cable?

A high-performance, low-loss, 50-ohm coaxial cable, often recognized as an LMR cable (a trademark of Times Microwave Systems), is engineered for diverse Radio Frequency (RF) and wireless communication uses. While LMR initially meant Land Mobile Radio, it is currently the widely recognized industry-standard for low-loss coaxial cables, offering a superior replacement for older types, such as the RG-series (LMR-400 is a prime example, replacing RG-8/9913).

LMR-195

LMR-195 is a 50 Ohm, low-loss, flexible coax cable for RF applications like wireless systems and antenna feeders.

LMR-240

LMR-240 is a low-loss, flexible coax cable for shorter runs, often used for Wi-Fi and mobile antennas.

LMR-300

LMR-300 is a flexible, low-loss 50-ohm coaxial cable used for RF/wireless communication like antenna runs.

LMR-400

LMR-400 is a low-loss, high-performance coaxial cable, often used for amateur radio and wireless applications.

LMR-600

LMR-600 is a flexible, low-loss coaxial cable, often used for high-frequency RF applications like Wi-Fi and cell boosters.

LMR-900

LMR-900 is a low-loss, high-performance coaxial cable used for RF applications, offering excellent signal integrity.

Key Characteristics and Construction

LMR cables are constructed to minimize signal loss (attenuation) and provide excellent shielding, making them highly effective for transmitting high-frequency signals over longer distances.

• Low Loss (Low Attenuation): This is the primary feature. LMR cables use a foam polyethylene (PE) dielectric (insulation layer) instead of the solid dielectric found in many older coax cables. This foam dielectric reduces signal energy loss, especially at higher frequencies (up to 6 GHz or more).

• Double Shielding: They typically feature dual shielding for superior protection against Electromagnetic Interference (EMI) and Radio Frequency Interference (RFI). This usually consists of:

  1. An aluminum foil tape bonded to the dielectric (providing 100% coverage).

  2. An outer tinned copper braid (offering enhanced durability and flexibility).

• Durability: The cables often have a UV-resistant polyethylene (PE) outer jacket, making them suitable for long-term outdoor and direct burial applications.

• Impedance: Standard LMR cables have a characteristic impedance of 50 ohms, which is the standard for most commercial wireless and radio communication equipment.

Common Application

LMR cables are used extensively in any system that requires a high-quality, low-loss connection between an antenna and the radio equipment.

• Wireless Communication Systems: Cellular networks, Wi-Fi (WLAN/WISP), and WiMAX.

• Antenna Feeder Runs: Connecting antennas to radio base stations, routers, or repeaters.

• Mobile and Two-Way Radio: Land Mobile Radio (LMR) systems, amateur (ham) radio.

• GPS and Satellite Communication.

• In-Building Communications: Distributed Antenna Systems (DAS).

• IoT/M2M Networks: Connections for telemetry and SCADA systems.