What is the residual phase noise of mixers LTC5510 and LTC5549 (LTC5549 with enabled LO frequency doubler)?
The entire mixer is done in SiGe.
The LTC5549 is not recommended for use above 14GHz on the RF port. I would suggest that you take a look at the LTC5553, which is a higher frequency version of the LTC5549. Unfortunately, this part does not have the LO doubler on chip, however.
Senior RF Applications Engineer