Hi,
I'm designing AD9963 based radio measurement device. I have zero-IF receiver using MAX2021.I have tested AD8338 based amplifier between ADALM2000 (based on AD9963) and MAX2021. It seems that I need about 60-80dB gain before output of AD8338 starts clipping.
I'm a novice in baseband circuit design, so I wonder if there is some rules and recommendations, how to optimize my circuit. It seems that some implementations are based on one amplifier stage:
And some others are more complex including several amplifiers and stages. What is benefit of having multiple stages?
It seems that typical IF amplifiers has gain around max 20dB. AD8338 can do 80dB, what is wrong with that?
I need to be able to measure signal amplitude. It sounds like it would be nice to have high amplitude for ADC. I'm not sure if I need actually 60-80dB gain, since noise is also amplifier. Maybe lower gain would be sufficient. So, how I can calculate required gain range for my baseband amplifier?