Product Description

4.Antenna layout specification
The CC2640R2 module is designed with a PCB onboard antenna with a
vertical polarization near omnidirectional radiation. This provides the effect of
wireless signal radiation without any additional ground plane, but it is important
to note that the specification is followed when installing this type of module to
another PCB.
The area around the antenna must be kept at least 20 mm with wires or
other metal objects. This applies to all layers of a PCB, not just the top layer. Any
conductive object near the antenna may seriously damage the performance of
the PCB antenna's radiation signal, resulting in a significant decrease in the
communication effectiveness. As shown in the figure below, the top three
layouts are correct and the bottom three are against the specification.
Picture 4.4 Antenna layout specification