AD9375 Waveform tranmission problem

Hi everyone,

when using the AD9375 to transmit signals (LTE, WCDMA or even simple 2 Tone signal), I always get a peak at the Center Frequency (i.e. Frequency of the Local Oscillator).
For example when I generate a 2-carrier LTE Signal with some Freq. Offset between them, I get this unwanted peak right in the middle ! (see picture)

How do I get rid of it ?

Many thanks !