6.5.2 External Antenna Placement Recommendations

The user must apply the following recommendations 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.

  • Do not place the antenna in direct contact with or in close proximity to the plastic casing/objects. (Except when the selected antenna specifically recommends it.)
  • 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 where the antenna must not be placed.

These recommendations are based on an open-air measurement and do 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 RNBD350 module.

The following figure illustrates an indication on how to route the antenna cable depending on the location of the antenna with respect to the RNBD350 PCB. There are two possible options for the optimum routing of the cable.
Figure 6-7. RNBD350 Antenna Placement Guidelines
Note: These are generic guidelines, and the recommendation is that the customers can check and fine-tune the antenna positioning in the final host product based on RF performance.