Our product is using AD9864, by out test, when the input IF signal with level of -90dBm directly into AD9864, and the DSP capture AD9864 SSI output IQ data then draw it with Matlab, the data is almost noise, we can't see valid signal. For -70dBm input or -30dBm input, the IQ data looks ok.
So, what's the possible reason for my problem, hardware or AD9864 configuration issue? Could anyone help me? Also I want to know what's the smallest input level that AD9864 can accept.
Here is my AD9864 register setting. And my IF input freq is 73.35MHz, LO freq is 71.1MHz.