I can't seem to get an output signal higher than -26 dBm out of the ADRF6780 mixer board. I am inputting a 2 GHz, 0 dBm CW signal from a signal generator into the IFIP port. And I am putting a 13.4 GHz, 3.6 dBm CW signal into the LOIP port. I am not using any filters or attenuators in my setup. The following screenshot shows the mixer output from the RFOP port.
I have the marker on the desired signal. I am not using the differential ports IFIN, LOIN, or RFON, because we don't want to invest in three 180 degree hybrids unless absolutely necessary, but I do have the VATT at the maximum gain (2600mv), and so I would still expect the output power to be much higher. (With VATT at minimum gain, desired signal drops to about -50 dBm)
I have tried the same setup on two separate boards and gotten the same results. I have also tested my cables, and I am only losing between 1-2 dB at the frequencies of interest.
Would the fact that I am not using differential input account for that kind of conversion loss? or is there a different reason for the loss, and what might cause it?