I'm looking to use the ADL5380-EVALZ with LO frequency f0=1,150 GHz and the modulated signal fm can be go from DC to 100 kHz.
For low modulated signals frequencies, the I or Q output are always at -70 dBm. But the technical sheet didn't mention a low frequency limit of the modulated signal.
Can you help me to solve this issue please.
The default configuration of the ADL5380 evaluation board uses a balun which is going to reject the DC component, thus you will get nothing out if RF=LO. To achieve DC output, you will need to bypass the balun as indicated in Table 5 on Page 34 of the datasheet.