7.4.1 Antenna Placement Recommendations

Particular attention must be given to the placement of the antenna and its cable. The following recommendations must be applied:

• Ensure that the antenna cable is not expected to be routed over circuits generating electrical noise on the Host board.
• Antenna should not be placed in direct contact or in close proximity of the plastic casing/objects.
• Do not enclose the antenna within a metal shield.
• Keep any components which may radiate noise, signals or harmonics within the 2.4 GHz to 2.5 GHz frequency band away from the antenna and, if possible, shield those components. Any noise radiated from the host board in this frequency band degrades the sensitivity of the module.
• It is highly recommended not to run the antenna cable alongside or underneath the module. It is preferred that the cable is routed straight out of the module.
• The antenna should preferably be placed at a distance greater than 5 cm away from the module. The figure below indicates the area where the antenna should not be placed.

This recommendation is based on an open air measurement and does not take into account by any metal shielding of the customer end product. When a metal enclosure is used, the antenna can be located closer to the ATSAMA5D27-WLSOM1 module.

The drawing below indicates how the antenna cable should be routed depending on the location of the antenna with respect to the ATSAMA5D27-WLSOM1 PCB. Two possible options for the optimum routing of the cable are described.

These guidelines are generic only; customers need to check and fine tune the antenna positioning in the final host product.