I am expecting a 3 Volt peak-to-peak output signal at 18MHz, but am measuring a
much lower amplitude. Why?
The AD8338 offers a small-signal -3dB bandwidth of 18MHz for all gains, however
at full scale output, the large-signal limitations of the device dominate. The
AD8338 has an output slew-rate of 50V/uS. Supposing that a triangle-wave input
were fed into the AD8338, in order to have a full slew of 3V, the maximum input
frequency would be 8.33MHz.