Hello Zhang,

I can answer part of your question. Hopefully someone familiar with amplifiers will tell you more.

Duty cycle (average fraction of time the device is on or is receiving a signal) multiplied by power of signal will give the average amount of power deposited into the probe or put out by the amplifier.

Some part of that power will have to be dissipated as heat. In the case of probe - almost all of that power goes into heat - if the probe is well tuned and matched.

Since each device has a limit in the amount of heat that can be dissipated, you can break the device by overheating it. So at any given level of power there is certain value of maximum safe duty cycle. If you lower power you can increase the duty cycle.

Hello Zhang,

I can answer part of your question. Hopefully someone familiar with amplifiers will tell you more.

Duty cycle (average fraction of time the device is on or is receiving a signal) multiplied by power of signal will give the average amount of power deposited into the probe or put out by the amplifier.

Some part of that power will have to be dissipated as heat. In the case of probe - almost all of that power goes into heat - if the probe is well tuned and matched.

Since each device has a limit in the amount of heat that can be dissipated, you can break the device by overheating it. So at any given level of power there is certain value of maximum safe duty cycle. If you lower power you can increase the duty cycle.

This post by Kirk Marat has a good explanation of how probes are damaged by high power irradiation.

Regards, Evgeny.