I'm using AD9364 on the Zynq board, using the no-os driver. When I am doing the transmitter performance test, I measure the signal power with different carrier frequency, using attenuation of 0dB. However the measured power (peak) is no higher than 4dB and dropped below 0dBm to around -12dBm from around 2.7GHz onwards. I am using the same settings as in the example code and use SPI write (ad9361_set_tx_lo_freq) to change the frequency. The measured power is far more less than the expected (according to the datasheet, ie 8dBm for 800MHz). Any clue?