How important/mandatory it is to use LVDS driver for LO input pins of AD8333? Is there any other alternative IC or circuit that I can use instead of it? I tried using LNA with the ac coupling circuit as shown in the datasheet, but I feel that it doesn't give the correct output. I get same amplitudes for I and Q irrespective of the input I give, so basically it always shows 45 degrees of phase between the real and the imaginary value. As far as I understood the working of AD8333, I suppose both of the amplitudes should vary so that I can deduct the exact phase angle between them. Do guide me if my concept about the IC is wrong. Is AD8333 supposed to give same amplitude levels for I and Q? If so, how do I calculate the phase and amplitude of my input based on output waveforms?