This page provides a brief overview of the main recommendations. You can also refer to the implementation guidelines defined in this document.
1. Module and host placement
RF modules are typically placed at the edge of the board due to antenna radiation or to minimize the RF path length to the antenna. The host can be placed close to the module (coexistence has been validated), but the orientation of the host is important, particularly the pins connected to the SMPS or clock sources, which could affect RF performances.
Here is a recommended placement of the STDES-67W611BU-U5 (board B2413):
the SMPS coil is placed on the opposite side of the module, and the crystals do not face the edge of the module.
2. Placement of the ST67W611M-B module (antenna version)
To optimize antenna performance, place the module in the middle of one edge of the PCB with no copper underneath.
An example of optimal placement is shown in the following figure:
Some not recommended placement are shown below:
Other antenna considerations:
- Keep the antenna area as far as possible from the power supply and metal components.
- Avoid placing any metallic materials near the antenna, as they can affect its performance.
- When the PCB antenna is operating, the ground or signal network near the end of the antenna experiences voltage fluctuations due to electromagnetic coupling. It is recommended to avoid placing sensitive components near the end of the antenna.