we are testing AD8318 evaluation board to rectify pulsed signal from a downconverter. The downconverter shows flat noise in the 1-2 Ghz band. This noise is rectified from AD8318 who shows an output signal of 1 V so we cannot see signals smaller than the corrispondent input value (ideally with no input signal the AD8318 shows about 2.2 V). Our pulses are modulated with 1.4 GHz signal and are about 100 ns long.
Since the pulse we want to detect is modulated at a fixed frequency, do you think that adding a narrow passband filter in front of the ad8318 at 1.4 GHzcan improve the detection or since the cause of unwanted detection is flat noise (who will of course enter also into the passband filter at the desired frequency) this will no give us any benefits?