Re: Where to put isolators in a microwave circuit?

I'd include them, if you are worried about it. So, build your attenuators a PI pads. You can always short out the series resistor if you don't need the additional isolation between your gain stages. If you need some isolation, then you'll have a spot for it.

Without knowing all of the performance specs of the system and the individual pieces, it's difficult to say if you'll need the attenuators to keep the preceding amplifiers happy. Build it, try it, fix it, repeat.

Thanks, I think it would not be too bad to add 1dB attenuators eitherway. Attenuation is not too much but it could help in stabilizing things if they accidentally go bad, how does it sound?
As you say, I will have to build the thing to see how it goes.