I use 2x HMC830LP6GE on a radio design.
The Datasheet recommends to connect the N/C pins to Ground.
However, when I look at the schematics of your eval board, some of of the N/C pins are connected to VCC1 and other voltages.
I am on layout now and I need a quick answer.
Please advise, Teodor
You can connect all NC pins to ground. NC pins have no connection to the die. Some eval boards connect nets through adjacent NC pins just to make the routing easier.