Operation Manual

Page 9 of 10
5 Host Integration Instructions
The Birdirra Module is a Limited Certified Transmitter Module (CTM) which is certified for use in Australia
and North America under FCC part 15.247 rules for Direct Sequence Spread Spectrum (DSSS) radios and FCC
part 15.212 rules for Limited Modular Transmitters (and the equivalent ACMA and ISED regulations).
The Birdirra Module is only approved for the specific FCC and IC rules listed above. The host system
manufacturer is responsible for compliance to any other FCC rules that apply to the host not covered by the
modular transmitter grant of certification.
The Birdirra module is designed for use in mobile or fixed devices where the device will be used at least 20cm
from nearby persons.
To ensure compliance with radio emissions limits system integrators should only use one of the recommended
antennas listed in section 4 and follow the implementation guidelines below:
5.1 Module PCB Placement
The host PCB should use a minimum of 4 layers with at least one layer used as a dedicated ground plane. The
Birdirra module should be mounted over a solid ground fill, with no PCB traces other than power routed directly
underneath the module. The trace from the RF_Output port should be 50 Ohm. The Ground pins of the module
should be connected directly to the dedicated internal ground plane PCB layer.
5.2 Embedded Antenna Implementation
For host systems using an embedded antenna, the recommended antenna is a Pulse Larsen type W3796. For best
results the antenna should be placed on the edge of the host PCBA and connected to the Birdirra module using
the matching circuit shown in Figure 1.
Figure 1 Embedded Antenna Matching Circuit and PCB Layout
Ground fill should be poured around and underneath the module, but no ground fill or internal ground planes
should be placed underneath the antenna. The trace from the Rf_Out port of the Module to the antenna should
be implemented as a 50R co-planar waveguide. The example shown uses a trace width of 0.445mm with a
0.25mm spacing to the ground fill, assuming a PCB dielectric constant of 4.3 and a dielectric thickness of