The HW and RF design for Sigfox are rather simple. We are using Wisol with direct connectivity to external antenna. We measured the output power on the antenna and it complies with the dB range of the different radio zones.
We are shipping the device to certification laboratory this week. We don’t expect any issues there.
If you want to be at upper range of power range, use a half lambda antenna instead of the provided quarter lambda antenna.
We also compared the device to other reference devices and the radio performance is on the regulation level.