• Place guard GND vias along the RF trace running from module to feed point of the antenna, in the host PCB.
The area directly below the RF trace must have a GND polygon pour, at least in the immediate layer below Top
layer.
• Do not have any signal traces below/adjacent to the RF trace in the host PCB. This is applicable to all layers
below the highlighted region in the following image.
• Do not use thermal relief pads for the GND pads of all components in the RF path. These component pads must
be completely filled with GND copper polygon. Place individual vias to the GND pads of these components.
• It is recommended that the antenna in the host board 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 antenna.
• Do not enclose the antenna in the host board within a metal shield.
• Keep any components which may radiate noise or signals within the 850-950 MHz frequency band away from
the antenna and if possible, shield those components. Any noise radiated from the host board in this frequency
band degrades the sensitivity of the module.
• Make sure the width of the traces routed to GND and VCC rails are larger for handling the peak TX current
consumption.
Figure 12-14. Top Layer Routing
ATSAMR30M18A
Application Reference Design
©
2018-2021 Microchip Technology Inc.
and its subsidiaries
Datasheet
DS70005384B-page 53