Definition of RF PCB
We can generally define an RF PCB as a printed circuit board designed to operate at medium to very high frequencies.
Frequency Range of RF PCBs
Therefore, any high frequency printed circuit board that operates above 100MHz is a radio frequency printed circuit board (UGPCB).
Actual Reference Frequency Range
However, when it comes to RF PCBs (UGPCB), the actual reference frequency range is usually 300MHz and above.
Microwave PCBs
RF PCBs operating above 2GHz are called microwave PCBs.