AD9082 DAC Capability

I guess another way to ask this is, Does the AD9082 generate meaningful power in it's 3rd nyquist zone? If not, do you have any MxFE that can generate signals in the 7G-8G range?

Could you clarify "IQ signal at 7 GHz"? Signal in the 3rd Nyquist zone would be heavily attenuated by the inherent sinc function of the DAC output, but the signal in 7-8 GHz can be generated from the second Nyquist zone using AD9802. The following thread may answer some of your question.  

https://ez.analog.com/wide-band-rf-transceivers/mixed-signal-front-ends-mxfe/f/q-a/540039/ad9082-for-802-11ax.

And the Table 9 of the AD9082 data sheet specifies the maximum data rate for various DAC configuration. 

Hope it helps.