2.7.1 External Antenna Placement Recommendations

The user must ensure the following for the placement of the antenna and its cable:

• Do not route the antenna cable over circuits generating electrical noise on the host board or alongside or underneath the Module. The recommendation is to route the cable straight out of the Module.
• If dipole antenna being used, do not place the antenna in direct contact or in close proximity of the plastic casing/objects.
• Do not enclose the antenna within a metal shield.
• The user must keep any components capable of radiating noise, signals or harmonics in the 2.4-2.5 GHz frequency range away from the antenna and, if feasible, provide shielding for such components. Any noise radiated from the host board in this frequency band degrades the sensitivity of the Module.
• Place the antenna at a distance greater than 5 cm away from the Module. The following figure illustrates the antenna keep out area (do not place the antenna in this area). This recommendation is based on an open-air measurement and does not take into account any metal shielding of the customer end product. When a metal enclosure is used, the antenna can be located closer to the PIC32WM-BW1 Module.

The following figure illustrates an i ndication on how to route the antenna cable depending on the location of the antenna with respect to the PIC32WM-BW1 PCB. There are two possible options for the optimum routing of the cable.