Data Sheet

Bluegiga Technologies Oy
Page 45 of 52
11 Layout Guidelines
Layout is very important for proper antenna operation when using the integrated antenna.
11.1 Internal antenna: Optimal module placement
Key points to remember are
 APx4 should be placed so that the antenna faces away from large GND planes.
 Typically the best placement is along one of the motherboard edges.
 Antenna facing out from board
 Antenna preferably in corner or placed outside the motherboard edge
 Important: The motherboard’s locking clips must be attached to GND.
 Optionally attach APx4 to the motherboard with metal screws and nuts as described in this document
 Either:
o Create a board cutout under the entire antenna part
or
o Place the module so that the antenna is outside the board edge
 We recommend issuing the motherboard design to Bluegiga for review in good time before ordering
the PCBs. Please allow for several days for such a review.
Figure 6: Example placement w/motherboard cut-out
Figure 7: Example placement, antenna outside motherboard
Important: The motherboard’s locking clips must be attached to GND.
11.2 External antenna
In case external antenna is used the RF output can be taken directly from the U.FL connector of the module.
In this case internal antenna placement can be ignored. See chapter 12.6 for approved antennas.
11.3 Thermal Considerations
APx4 will heat up to some extent during use, especially due to Wi-Fi power consumption during high-
throughput transmissions. APx4 can be attached to the motherboard with metal bolts to allow some heat
transfer to the application board ground plane.
11.4 EMC Considerations for Motherboard
Unwanted electromagnetic radiation may arise from a combination of APx4 and a motherboard if not carefully
designed.