4 MHZ freqency solution

There are plenty of digital gates, flip-flops, etc that work far faster than that, and there is no noise spec. I know that is not what you were really asking about, but it would help to be as specific as possible (describe *what* circuit and use as well).

i want to amplifie an analog signal wich have a 4MEGAHERTz frequency i work on doppler effect to measure the blood velocity. thank for your help