Reference Manual
Table Of Contents
- Digi XBee® 3 RF Module Hardware Reference Manual
- General XBee 3 specifications
- IEEE 802.15.4-specific specifications
- Mechanical drawings
- Pin signals
- Design notes
- Regulatory information
- XBIB-C development boards
- Manufacturing information
- Troubleshooting
Design notes Design notes for RF pad devices
Digi XBee® 3 RF Module Hardware Reference Manual
36
Following good design practices is essential when implementing the RF trace on a PCB. Consider the
following points:
n Minimize the length of the trace by placing the RPSMA jack close to the device.
n Connect all of the grounds on the jack and the device to the ground planes directly or through
closely placed vias.
n Space any ground fill on the top layer at least twice the distance d, for Micro modules at least
0.028" and for surface mount modules at least 0.050".
Additional considerations:
n The top two layers of the PCB have a controlled thickness dielectric material in between.
n The second layer has a ground plane which runs underneath the entire RF pad area. This
ground plane is a distance d, the thickness of the dielectric, below the top layer.
n The RF trace width determines the impedance of the transmission line with relation to the
ground plane. Many online tools can estimate this value, although you should consult the PCB
manufacturer for the exact width.
Implementing these design suggestions helps ensure that the RF pad device performs to its
specifications.
The following figures show a layout example of a host PCB that connects an RF pad device to a right
angle, through-hole RPSMA jack.