Amplitude limiter:

Microwave amplitude limiter is mainly used for power regulation, the signal passes without attenuation at low power and attenuates considerably when the power rises to a fixed level called "threshold level", the output power remains stable even if the input power increases beyond the threshold level. 

Typically, the amplitude limiter can be used to protect power-sensitive parts, from burn-in from a strong signal.

 It can also be applied to microwave sweep signal generator or phase detector to keep the output signal stable.

Technical standards :