Nrf24l01 smd pcb placement tips
You need to keep the ground plane away from the antenna. The rest of the module doesn't care (and having a ground plane under it can help with unwanted EMI).
Here's a design I did recently for a customer with the same module in it. It's placed near the edge of the PCB with the ground plane cut out around the antenna:

That layout is actually set up for either the small SMD, the SMD with PA+LNB or the thorugh-hole version. The important thing is that there is a nice big exclusion zone in the ground plane where the antenna is.