what's the GBP of AD8321, which is shown in the datasheet, and if multi-chips connect in series, how to carry out impedance matching.
if the input signal rang from 1-100Mhz(less than 2mV), how much is the amplification factor
Can you tell me what range of signal amplitudes that the VGA input will see? What do you need for dynamic range. Do you need more than one channel? If your bandwidth is limited to 20MHz, I don't think you need an RF VGA like 5330 or IF VGA…