I am currently using the software defined radio AD9361+ZedBoard for SDR development. I was trying to tune the 2.4GHz RF frequency to 5.9GHz. According to the datasheet of AD9361, it can accommodate 70MHz-6GHz RF freuqencies. However when I increase the RF band to 4GHz or higher, the signal is totally ruined. Do you have any suggestion on potential possibilities?