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
35
Through-hole embedded antenna keepout area
Notes
1. We recommend non-metal enclosures. For metal enclosures, use an external antenna.
2. Keep metal chassis or mounting structures in the keepout area at least 2.54 cm (1 in) from the
antenna.
3. Maximize the distance between the antenna and metal objects that might be mounted in the
keepout area.
4. These keepout area guidelines do not apply for external RF connectors.
Design notes for RF pad devices
The RF pad is a soldered antenna connection. The RF signal travels from the RF pad connection (pad
33 on micro modules and pad 36 on surface-mount modules) on the device to the antenna through an
RF trace transmission line on the PCB. Any additional components between the device and antenna
violates modular certification. The controlled impedance for the RF trace is 50 Ω.
We recommend using a microstrip trace, although you can also use a coplanar waveguide if you need
more isolation. A microstrip generally requires less area on the PCB than a coplanar waveguide. We do
not recommend using a stripline because sending the signal to different PCB layers can introduce
matching and performance problems.