The PCB layout guidelines recommended in this section are to be used when the PCB requirements of Section 10.4.2 cannot be strictly followed. This would include deviation from the recommended 4-layer PCB stackup, dielectric constant, and outlined design rules. Figure 10-8 shows the RF placement and routing of the CC2651R3SIPA module with the 2.4-GHz integrated antenna.

Figure 10-8 Alternate Module Layout Guidelines

Follow these RF layout recommendations for the CC2651R3SIPA module when using the integrated Antenna:

• Dimensions A thru F in Figure 10-8 must be strictly adhered to for optimal RF performance
• For optimal efficiency of the antenna, its best to have a minimum 10-mm ground plane on either side of the module on all layers as shown with dimension G in Figure 10-8
• There must be at least on ground-reference plane under the module on the main PCB
• The ground loop should only be on the top layer of the board and not on all 4-layers.
• A π matching network implementation in the ground loop allowing for tuning of the integrated antenna for optimal performance.