It is a question about AD8351.Using the evaluation boardAlthough the gain is set to 18 dB (RG = 50 Ω) as a single end, the gain characteristic flattens only to about 120 MHz in the frequency response. In the data sheet, it is a gain flat up to 400 MHz, but please let me know if there are things that can be considered about the cause. Thanking you in advance.
The load resistor affects the gain as well. Make sure you are using the same load resistor as the datasheet in order to get the same frequency response.