I need help selecting an amplifier to amplify signal after an IQ mixer that is mixing signal down to DC. My requirements are as follows:
-Freq range: DC to 200 + MHz
-50 Ohm matched input and outputs (this could be accomplished with an evaluation board)
-Evaluation board option
-Gain: > 10
I had purchased the AD8330 - however the evaluation board is AC coupled, which completed distorted our DC signal. So I now need an alternative that will accomplish similar amplification (it does not need to to be variable gain), and I need to make sure is that the evaluation board associated with the amplifier is NOT AC coupled.
Your requirements can probably best be met with one of the following Current FB Opamps together with another inverting stage (with G=2 to make up for the voltage division with a 50 ohm series output resistor into the 50-ohm load).:
-- AD8003 (Triple 1.5 GHz)
-- AD8009 (Single 1.58 GHz)
-- AD8003 (Single 1 GHz)
Note that BW at G=10 will be much less than the listed F3dB which are for G=1. The Zin=50 requirement can be met by using Rg=50 and Rf=500 ohm, which changes frequency response slightly, but should still be > 200 MHz. If the input is GND referenced, they need to run on +/- supplies. Depending on your DC accuracy requirements, some means of offset adjustment may also be needed.