There are two reasons a schottky diode will fail:
1) static damage
2) high microwave power
For static damage, a small value series cap that only passes microwaves, and a shunt inductance to ground (or if narrowband, a quarterwave stub to ground) will probably fix it.
If it is high microwave power, you have to differentiate from situations where you know ahead of time that the power it rising (like you have a 10 watt transmitter sharing the antenna, and know when you are going to turn it on)...or situations where you do not know when high power will arrive (like taxiing around an airport surface and getting blasted by someone elses radar pulse).
For times when you know there is high power coming, a simple pin diode switch, turned to isolation mode before the pulse comes, will do it. They can be designed to handle very high power levels without much insertion loss.
For times when you do not know a pulse is coming, you will need a passive limiter. A thin PIN diode will turn on all by itself (assuming there is a DC path to ground for self bias currents). But it has some capacitance that is a bother at higher frequencies. Matching with series inductors to form a lowpass structure (bond wires make good inductors!) is one way. Using a thicker PIN diode (less capacitance) and a detector diode scheme to provide bias to it is possibly a better way. Another scheme is to use two PIN diodes, a thick one up front, and a thinner one quarter wave further down the line, works too.
Rich