The Keysight 11693A can be used to protect the input circuits of spectrum analyzers, counters, amplifiers, and other instruments from high power levels with minimal effect on measurement performance. The Keysight 11693A microwave limiter (0.1 to 12.4 GHz, useable to 18 GHz), guards against input signals over 1 milliwatt up to 1 watt average power and 10 watts peak power.