I found a problem similary with" Tx VCO Leakage Effects on Receiver Performances ".
When I configure ad9361 works as FDD,Tx Freq = 2400.000MHz.
If Rx Freq = 1200.250MHz or Rx Freq = 2400.250MHz or Rx Freq = 4800.250MHz , there will be many spurs in the transmitting spectrum.
After investigation,I found that the spurs will be smaller if the difference between Tx vco frequency and Rx vco frequency greater than pll filter bandwidth and will disappear if the difference between Tx vco frequency and Rx vco frequency greater than 1MHz.
What are your recommendations to minimize the spurs.