RE: Radio Test Example Channel Selection Issue : FCC Certification

dev_000 — Tue, 14 Jun 2016 08:02:01 GMT

Thanks Kristen. That should I ideally solve it. I thought radio_tx_sweep_start was only channel sweep. My mistake.

Regarding the emissions, Thanks for the inputs, I was under the limits for fundamental and higher when I was "using" the advertising channels for testing. :)

RE: Radio Test Example Channel Selection Issue : FCC Certification

FormerMember — Tue, 14 Jun 2016 07:37:05 GMT

1) From what I can see in your code, the radio is never set to start transmitting, the function radio_tx_sweep_start(..) makes it start transmitting. For your reference, I have attached a modified version of the radio test example that is set up to transmit one channel: radio_test_setup_one_channel.zip (SDK 11, folder: ..\examples\peripheral)

2) You can use a timer to make the radio_test example switch frequency every given time interval.

3) It looks like Triarchy Technologies has some smaller and cheaper spectrum analyzers.

Note that in addition to check the output power in the in the 2.4 GHz band, FCC does also have maximum radiation requirements for the harmonics and RX Lo. For FCC, the maximum peak level for the harmonics is -21 dBm, and the average for the harmonics should be less than -41 dBm. RX Lo should be less than - 41 dBm. I would recommend you to have a few dB margin to those requirements, in order to make sure that you pass.

The middle of the harmonic bands will be at approximately 4.85 GHz, 7.3 GHz, 9.75 GHz, 12.2 GHz, and the RX Lo and RX Lo/2 will have center frequency at 2.79 GHz and 1.395 GHz, respectively.

I would recommend you to take a look at the whitepaper "Regulatory and Compliance Standards for RF Devices"