4.6.2 External Antenna Placement Recommendations

The following recommendations must be applied for the placement of the antenna and its cable:

• The antenna cable must not be routed over circuits generating electrical noise on the host board or alongside or underneath the module. It is preferred that the cable is routed straight out of the module.
• The antenna must not be placed in direct contact or in close proximity of the plastic casing/objects (except when the selected antenna specifically recommends it).
• Do not enclose the antenna within a metal shield.
• Keep any components that may radiate noise, signals or harmonics within the 2.4-2.5 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.
• The antenna must be placed at a distance greater than 5 cm away from the module. The following figure illustrates the antenna keepout 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 WBZ45 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 WBZ45 PCB; there are two possible options for the optimum routing of the cable.