What is the lowest RF input frequency that the ADC12J4000 can measure? The "Electrical Characteristics" section in the datasheet takes various measurements from Fin = 350 MHz to 2.4 GHz. The reason I am asking is because I am injecting a wideband signal into the ADC and the output seems to be filtered on the low end. For example, a 250 MHz - 750 MHz gave a nice sharp edge at 250 MHz, but when I injected a 100 - 1100 MHz waveform, the output was attenuated. It looked like the response of a high pass filter.
I would think that this ADC could measure from DC to 3.2 GHz with no problems, since the bandwidth is 3.2 GHz as advertised.
