nRF9160 MIPI RFFE support for more than one device

[Lukáš]

Hi,

Currently, nRF91 supports only one MIPI RFFE-controlled device. In our solution, we would like to have two MIPI devices - one pair of LTE switches as in Thingy:91 for matching network selection, and NB-IoT/CAT-M1 front-end module. When will be support for more MIPI RFFE devices released? 

Best regards,

Lukas

[Andreas]

Hi Lukas,

 

It turns out nothing is planned as this is not that straight-forward, especially supporting a FEM device external to the SiP. Any gain in the RX path must be known to the LTE modem, and any gain in TX must be calibrated to meet all requirements for TX. On top of that is regulatory requirements, which is unchartered terriotory.

Have you been able to find a FEM that satisfies all these requirements though, which you are confident will work? Do you have a part number or datasheet (feel free to open a private ticket if this includes any confidential information)? Knowing what we are dealing with might make it easier to evaluate the feasibility.

 

Best regards,

Andreas

[Lukáš]

Hi Andreas,

Thank you for your reply. We are not sure about the particular FEM selection. The SKY66430-11 came around us and we are just interested if it can be integrated into our future products. The SKY68020-11 might also be possible. Do you think it would be possible to integrate with the nRF9160?

Let's keep this public, it might help other users with their decision.

Best regards,

Lukas

[Andreas]

Hi Lukas,

 

None of these can be integrated with nRF9160. SKY66430-11 is a SiP modem and SKY68020 would be more similar to what is already inside the nRF9160. Furthermore the saturated TX output power of SKY68020 is the same as for nRF9160, even if you were to integrate it the output power would not increase, it would just destroy the nRF9160 network and regulatory compliance.

 

Best regards,

Andreas