from output if i operate with 50 Ohm load?
First thing I should say is that ADA4302-4 is intended for use in a 75 Ohm
broadcast video system, so you would need to match the impedance to 75 Ohms if
you want to use the part in a 50 Ohm system.
The ADA4302-4 has very few specifications which apply to the signal amplitude.
However, the 1dB output compression occurs at a signal level of +8dBm @ 75 Ohms
which corresponds to +/-0.97V. The device has a gain of 4.6dB so that means the
corresponding input is +/-0.59V.