Maximum Power Output of SODAQ ONE's LoRa Anntena Connector?

ONE
1

As the title says what is maximum output of the LoRa connector.
Is it possible to connect a antenna to the module with a 1 meter long cable?

2

Hi Christiaan,

The maximum output is +14dBm.
By default the modules is transmitting on +14dBm.

14dBm = 25mW output power

It is no problem to connect a cable of 1 meter.
The signal loss is depending on the quality of the coax cable.
The loss should be minimal with a high quality cable.

Regards,
Jan

3

Hi Jan,

I see that the RN2903 module has an output power of 18.5dBm. What is the cause for the 4.5dBm loss? When addressing the module directly the power id can be set to 5 which though the lorawan regional parameters translates to 20dBm.
is there an explanation for this?
In saying this, what should the Output Index (pwr) in the tracker software be set to to achieve maximum output? Would it be 7 or 8 (between 14 and 16dBm)? However I notice the default is 1.

Cheers
Cam

4

Hi Can,

Where did you find this table 29?

When I look at the datasheet from Microchip of the RN2903 on page 1:
• TX Power: adjustable up to +18.5 dBm high
efficiency PA
http://ww1.microchip.com/downloads/en/DeviceDoc/50002390B.pdf

Output Index (pwr) is by default 1, maximum power for the RN2483
By default the RN2903 is using pwr 5
You can choose 5, 7, 8, 9 or 10

See 2.4.8.7

Regards,
Jan

1 Like
5

Hi Jan,

Thanks for the reply, the table came form the regional parameters for Lorawan. I just use as a guide for translation.

I ended up using a spectrum analyser to find the max power :smile:

Cheers
Cam

6

And what was your result?

Best Regards,
Thomas

7

I can’t remember the exact values but I believe it was between -10dBm and -14dBm depending on the bandwidth (spread spectrum). If you are concerned, you should use a spectrum analyser. I noticed a higher output when measuring the output of a Microchip RN lora mote. There could be losses from Microchip RN module on the Sodaq to the output connector.

HTH
Cam