We are designing a ultra low noise USB 2.0 hub.
I am thinking to add a common mode choke to + and - of the USB connector, in addition to the D+ and D- choke to remove the common mode noise. I am aware that adding a CMC on the D lines will degrade the signal integrity but I am using a signal conditioner afterwards.
My question is: will the additional CMC (on + and -) help with common mode noise reduction and will it interfere with USB signaling ?