Front end Bluetooth module with RX gain

RE: Front end Bluetooth module with RX gain

ketiljo — Mon, 12 Apr 2021 13:19:31 GMT

This has to do with the noise factor in both the external LNA and the existing internal LNA. The filtering is happing in the IF filter in the receiver as usual. https://www.digikey.no/no/articles/low-noise-amplifiers-maximize-receiver-sensitivity

The drawback by using a LNA is that the selectivity is worsened by the added gain.

RE: Front end Bluetooth module with RX gain

MULTIVOICE — Fri, 09 Apr 2021 15:59:22 GMT

Hi Ketiljo

Thanks for your reply.

As I understand it, for the improved sensitivity of 4 to 5 db it must be focused in amplifying the 2.4 band and the LNA is acting like a filter. Is this assumption correct?

Do you have any data sheets with test results showing the increased sensitivity with the 16db of RX gain vs no gain?

RE: Front end Bluetooth module with RX gain

ketiljo — Fri, 09 Apr 2021 11:44:44 GMT

You will gain some sensitivity with a LNA, but less than the gain in the LNA because, as you say, noise will also be amplified. With the 16 dB gain in the LNA, the sensitivity will improve by 4 to 5 dB.