QUESTION

Question

Hi,
I have new project, where many wireless technologies will be (or can be) used: NB-IoT and LTE Cat M (multiple bands), WiFi and BLE, LoRa and GNSS. Only one technology at a time will work (beside a GNSS). I consider use of Draco antenna to our new project, because it covers almost all bands of interest (altough WiFi band is not specified, it should also work, based on provided vswr characteristics and efficiency specification in neighbouring bands). Choosing LTE / WiFi  or LoRa can be easily done with RF switch. I wonder if it is possible to permanently connect GNSS module to the same antenna. I was looking for triplexer, but found nothing. Now the only idea I have is to use cascaded diplexers, as in the picture below (WiFi module is neglected), but I am afraid it could be risky solution (and don't know if diplexers differetating 1575 and 1800 MHz exists). Do you have any ideas how to do this?

Best regards,

Jakub

Answer 1

Hi Jakub,

The Draco will operate in the bands you are interested in however we have not utilized the Draco in the manner you are referring to due to the loss through each of the diplexer chains. It is most common to use an external GPS antenna if you are not using the location information given through the LTE base-stations.

In theory your diagram will work but take into account the losses (especially the high band going through three diplexers) which could significantly reduce the overall performance and head you from passing carrier approval.

Best regards,

Geoff S.