I'm evalutating adrv9026 with EVAL-9026 and my own FPGA card and I got a bad 3rd Harmonic Distortion (HD3) on my ADRV9026. I'm using 3600MHz LO, Tx Test Tone with 0 dBFS gain and 0dB transmitter attenuation. The Tx Test Tone output is about 6dBm and the lower 3rd harmonic is about -45dBc, which is far more worse than the datasheet figure at 3800MHz LO.
Hope to get some advice to improve or debug it.
Thanks so much for your help!