NINA-W1 series - System Integration Manual
UBX-17005730 - R07 Design-in Page 28 of 47
• The VCC_IO connection must be as wide and short as possible.
• The VCC_IO connection must be routed through a PCB area separated from sensitive analog
signals and sensitive functional units. It is a good practice to interpose at least one layer of PCB
ground between VCC_IO track and other signal routing.
There is no strict requirement of adding bypass capacitance to the supply net close to the module.
But depending on the layout of the supply net and other consumers on the same net, bypass
capacitors might still be beneficial. Though the GND pins are internally connected, connect all the
available pins to solid ground on the application board, as a good (low impedance) connection to an
external ground can minimize power loss and improve RF and thermal performance.
3.3 Antenna interface
As the unit cannot be mounted arbitrarily, the placement should be chosen with consideration so
that it does not interfere with radio communication. The NINA-W102, NINA-W132 and W152
modules with an internal surface mounted antenna cannot be mounted in a metal enclosure. No
metal casing or plastics using metal flakes should be used. Avoid metallic based paint or lacquer as
well. The NINA-W101 and NINA-W131 modules offer more freedom as an external antenna can be
mounted further away from the module.
⚠ According to the FCC regulations, the transmission line from the module’s antenna pin to the
antenna or antenna connector on the host PCB is considered part of the approved antenna
design. Therefore, module integrators must either follow exactly one of the antenna reference
design used in the module’s FCC type approval or certify their own designs.
3.3.1 RF transmission line design (NINA-W101/W131/W151)
RF transmission lines, such as the ones from the ANT pad up to the related antenna connector or up
to the related internal antenna pad, must be designed so that the characteristic impedance is as
close as possible to 50 Ω. Figure 23 illustrates the design options and the main parameters to be
taken into account when implementing a transmission line on a PCB:
• The micro strip (a track coupled to a single ground plane, separated by dielectric material)
• The coplanar micro strip (a track coupled to the ground plane and side conductors, separated by
dielectric material)
• The strip line (a track sandwiched between two parallel ground planes, separated by dielectric
material).
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