13.1.1 ATWINC3400-MR210CA Module Placement and Routing Guidelines

It is critical to follow the recommendations listed below to achieve the best RF performance:

• The module must be placed on the host board and the chip antenna area must not overlap with the host board. The following figure on placement reference shows the best, poor and worst case module placements in the host board.

  

  CAUTION: Do not place the module in the middle of the host board or far away from the host board edge.
• Follow the host board mechanical recommendation, ground plane and keepout recommendations, as shown in the following figure. Module chip antenna is specifically tuned for this host board mechanical recommendation, as shown in the following figure. The host PCB must have a thickness of 1.5 mm.
  • Follow the module placement and keepout recommendation, as shown in the following figure.
    • Avoid routing any traces on the top layer of the host board, which is directly below the module area.
    • In the keepout region, there must be no copper traces in all signal layers.
    • Avoid placing any components (like mechanical spacers, bumpon and so on) on the host board close to the chip antenna region.
    • Place the GND polygon pour below the module on the top layer of the host board. Avoid breaks in this GND plane and ensure continuous GND plane for better RF performance.
    • The GND polygon pour in the top layer of the host board must have a minimum area of 20 x 40 mm.
    • Place sufficient GND vias on the host board edge and below the module for better RF performance.
    • Having a 5 x 5 grid of GND vias solidly connecting the exposed GND paddle of the module to the ground plane of the host board is recommended. This will act as a good ground and thermal conduction path for the ATWILC3400-MR210CA module. The GND vias must have a minimum via hole size of 0.2 mm.
    • The antenna on the module must not be placed in direct contact or close proximity to plastic casing/objects. Keep a minimum clearance of > 7 mm in all directions around the chip antenna.