NRF24L01 power amplifier working!

Hi all.

This post is for all those who wants more power from their Nordic.

I have tested the HMC605LP3 from Hittite with good results on the NRF24L01.

The advantage over other PAs is that no RF switches are required, due to the internal bypass. Also, the input and output impedance are 50 ohm, so no matching network is required on any side of the amplifier, this implies a very simple layout design.

The bad is the 5V supply required for maximize output power, but with 3.3V also works well.

Shipping cost from hittite to Spain is very high too, even if purchase only a couple of pieces. Anybody knows other sources for this chip? Maybe would be an interesting thing that Sparkfun can include this item on its product list.

I think this is the easiest way to increase output power on the NRF24L01, but any other solution will be welcome.

Greetings from Spain.

Sounds good!

Can you share some more details with us, like how much extra range did you get (at what bitrate / error rate) ?

Best regards,

Marco

I did not make a line-of-sight range test, because in my final application there is many obstacles between transceivers and line-of-sight range is not a useful value, but for your reference:

bitrate: 1Mbit, shockburst mode, auto ACK enabled, auto retransmit enabled (max 15 rtx), 5 address bytes + 32 payload bytes (32 00´s , worst case), 0 dbm power on NRF24L01, rf channel: 2. I have used the “Mica” antenna from “Antenova” on both sides, mounted closer to the PA in the same board as Nordic, on 1.6mm FR4 2 layer PCB.

without amp:

maximun aceptable range: about 15m (50 ft), with 2 brick walls between transceivers.

with amp (3,3V supply):

maximun aceptable range: about 40m (130ft), with 5 brick walls between transceivers.

“maximun aceptable range” means that in 80 pecent cases, the data is transmited and ACK received on the first attempt (number of rtx=0). On remaining 20 percent, a number of rtx are needed or transmission definitely failed after the 15th rtx (I have noted that, if do not achieve the transmission at first attempt, will probably do not achieve it either on further retransmits).

I have ordered the NRF24L01P to test it at 250kbps. I will report the results.

by the way: sorry for my poor english.