The RF power detector
Many articles regarding applications of the logarithmic amplifier AD8307 by AD, as RF power sensor, were written and are available on the net.
As personal experience, it seems to be a really stable and reliable component.It is connected to the IF output of the down conversion receiver and gives a DC voltage output proportional to the power of the RF signal received at the antenna. For this application, with a careful grounding and shielding, following circuit gives good results in terms of stability and linearity :
