Grounding on a 4 layer PCB

[Imran]

Hello,

When designing a 4 layer board with the nRF51822, should I connect the chip and impedance matching circuit to analog ground and keep the other digital chips isolated to a digital ground? Or can I connect everything to a common ground and isolate the impedance matching circuit with a keep out area on the inner layers?

Imran

[FormerMember]

It is only necessary to separate between analog and digital ground if there are some noise sensitive components on the PCB. (Our chip will create some noise when the radio is being turned on.)

If there aren't any noise sensitive components on the PCB, everything can be connected to one common ground.

Yes, under the matching circuit/matching network the inner layers should be cleared out.