Looked around for a small & low power RF detector and this hits all the marks. I'm looking to take the design and expand it a bit. As the sensor output and ADC input are quite close in range, the "glueless" (not sure what to call a lack of filtering, buffering, conditioning) interface seems to worth just fine. Would it be worth putting a LPF between the two of them for higher noise immunity? And on that note, are there any other suggestions to improve this circuit?
Btw, I'll be using it to measure incident and reflected power to an antenna in S-band