RF Limiters For Defense Systems, 1 To 18 GHz: LIM Series

Narda, an L-3 Communications company, introduces the LIM Series of broadband PIN diode-based RF limiters designed for air, ground, or sea-based defense applications. They handle high input power levels, have fast recovery times, and are available for drop-in mounting with removable connectors.

RF limiters are important elements in the receive section of electronic warfare, electronic countermeasures, and other systems, where they attenuate signals whose strength is above a specific point, protecting sensitive components such as low-noise amplifiers and other components from damage or destruction.

The broadband LIM Series limiters include the LIM-101, which covers 1 to 18 GHz, has flat leakage of 100 mW, a recovery time of 200 ns, and handles an RF input power of 2 W CW and 150 W peak (1 µs pulse width, 1% duty cycle), and an operating temperature range of -55 to 95 C. The LIM-201 and LIM-301 cover 2 to 18 GHz, have flat leakage of 150 mW or less, a recovery time of 100 ns and 200 ns respectively, handle an RF input power of 3 W CW and 500 W peak (1 µs pulse width, 0.1% duty cycle), and operate over a temperature range of -30 to 85 C. Maximum VSWR of all models is less than 2:1 at any frequency, connectors are SMA female and can be removed, and dimensions are 25.4 mm x 16.5 mm x 7.9 mm.

All three RF limiters meet military specifications for humidity, shock, vibration, temperature, and altitude. They are available as single-function devices or in integrated assemblies (IMA's) that include switches, amplifiers, attenuators, filters, and other microwave components.