The HMC3716 data sheet shows differential inputs with a 50 ohm differential load. Also, it shows the NREF and NVCO ports being tied to the internal bias networks.
Must the NREF and NVCO ports be bypassed, or can the REF/NREF amd VCO/NVCO inputs be driven as true differential inputs? Thank you.
The REF / NREF and VCO / NVCO ports can be driven differentially but as you noted they are matched to a 50 ohm differential load internally so depending on the impedance your driving the HMC3716 with you may want to provide some external matching.