I am currently developing a heterodyne receiver for use in a thesis project and am considering the use of an active mixer in the front-end to provide conversion gain. In my design application, it is critical to minimize losses as much as possible. Furthermore, our system design must also minimize the noise floor, so I've been looking very carefully at the options currently available for my desired bandwidth. Optimally, this band is from 4 to 9 GHz, but I can be more flexible and operate between 5.5 and 8 GHz.
While searching, I noticed that Hittite manufactures the following part: HMC951LP4
It seems to offer considerably low noise figure and substantial conversion gain within my band. However, I would like to know if it is possible to leave RF and LO power flowing to the part even in the absence of bias. It is important for my design that the mixer can be safely turned off for a time, even when there is power going to the LO and RF ports. If this can be done, what sort of isolation between RF and IF1/2 might I expect when the bias is turned off? Thank you!