Analog CMOS switch and switched amplifier?

[asrock70]

I need precision three step amplifier, working in 50Ohm system on frequency order MHz.
Due BW is impossible use one amplifier.
First idea is use three amplifier with fixed gaind and switching relay.
This is no problem, but switching time relay is in order ms, so that I thing about analog CMOS switch, for example ADG1436
https://www.analog.com/en/switchesmultiplexers/analog-switches/adg1436/products/product.html
This switch have good switching time, but have resistance 1,5Ohm and parasitic capacitance, current lekage and another.
I seed appnote or example with error analysis for use analog switch in simial aplication.
You advise?

 

[crutschow]

If 1.5 ohm ON resistance is too high, Analog Devices has several switches with less than 1 ohm ON resistance. You might use one of those.

As far as the parasitic capacitance and leakage currents, you just need to account for those in your design. A Spice simulator can help see the effects of that. Leakage currents are not likely a problem in a 50Ω system.