Data Sheet

UBX-18017567 - R07 Appendix Page 38 of 46
C1 - Public
Figure 16. Test set-up.
A.1.4 RF trace PCB routing
The PCB routing connecting the module’s antenna pins to module board U.FL connectors are
designed with coplanar microstrips. Coplanar microstrips are also used on the carrier board
connecting the U.FL connectors with the SMA connectors to which the external antennas or test
equipment are connected. Figure 17 and Table 37 shows the design stack-up including dimensions of
the 50 Ω coplanar microstrips implemented.
Regarding the coplanar microstrips the ground planes beside the signal trace are connected to the
inner layer ground plane using vias. The vias are placed with a maximum distance of 0.5 mm to the
coplanar ground edge and a maximum pitch of 2 mm. The top layer is coated with generic LPI solder
stop mask.
The SMA connectors on the carrier board are used for mounting antennas. For Bluetooth and Wi-Fi
operation in the 2.4 GHz band and Wi-Fi operation in the 5 GHz band, the module has been tested and
approved for use with antennas up to 2 dBi antenna gain.
Figure 17: Coplanar micro-strip dimension specification
Item Value
S 200 µm
W 700 µm
T 35 µm
H 800 µm
𝜀

4.3
Table 37: Coplanar micro-strip specification
The mechanical dimensions of the module board’s microstrips and position of the pi network
impedance matching components are shown in Figure 18. Figure 20 shows the components used for
the PI network impedance matching. Here only series 0 ohm resistors are used. The inner layers have
the same dimensions and are filled with ground. No RF traces are routed in these layers.