Maximum allowed output power ESB

[TinyRick]

Hi Nordic folks,

We are developing a product using nRF52832 with a Power Amplifier (RFX2401C) for extended range. For communication we are using ESB with some modifications to allow the use of a PA. The PA will add +22dBm to the output power.

We plan to release the product in Europe and USA.

Do anyone have a summary of what we will have to do to comply with the regulations in these countries? I am sure that someone has had the same kind of problem before here.

I have read a bit of the regulations for devices operating in the 2.4GHz band in Europe (EN 300 328), but as most of these documents this can be hard to read sometimes. Therefore we would like to know if someone on this forum has some tips.

[bjorn-spockeli]

Hi Rick,

As far as I know, you're allowed to transmit up-to +30dBm in the US as long as the bandwidth at 6dB is larger than 500kHz.

In Europe there are several regulations when transmitting above 10dBm, described in ETSI EN 300 328 Chapter 4.3.2. The most "problematic" part is 4.3.2.3 Power Spectral Density, which is limited to to 10dBm per MHz. Thus, with a 2MHz bandwidth the maximum output power of 13dBm, transmitting above this limit will require you to hop between frequencies (minimum of 15 channels)

In addition there is a requirement to "Listen Before Talk" (chapter 4.3.2.6.2.2), i.e. you need to check whether the channel is used or not before transmitting as well as requirements of the Medium Utilization, i.e. duty cycle.

Best regards

Bjørn

[bjorn-spockeli]

@AmbystomaLabs: Yes, I should have stated that, I just reckoned it wasnt necessary since we're talking about ESB. Yes, I strongly recommend contacting a testing facility/lab regarding which parts of the regulation your design will have to comply to.