Microwave Tube and its time response

Hi
I am working in the field of signal processing and digital communication. I want to know some introduction notes about microwave tube and its time responce. for example can any kind of tube transmite short pulses without distortion? or how can I model this distortion?

any tube is band limited, if your tube is band wide enough, then any short pulse shall go pass it, if it is not ,then the tube like a filter

Maybe it's about traveling wave tube amplifier TWTA - used especially in satellite links. I know that in some simulation programs there is a model for TWTA channel - and signal processing may be used to adapt the signals for this channel. If this is the case, look for TWTA papers.