Linear 700Mhz digitally controlled signal Attenuator

Normally it is hard to find a digital potentiometer with frequency grater than 5 Mhz. This design can provide digital signal attenuation upto 700Mhz in 125 steps. The steps can be modified by changing the resistances.

Working principle:

This works by summation of the weighted value of the signal.

Vout= (RaKa+RbKb+RcKc) Vin