CC1101 compliance with EN300-220-1

Konstantin Bilozor

Other Parts Discussed in Thread: CC430F5137, CC1101, CC1120

Hello guys,

We have an idea to use CC430F5137 SoC with CC1101 radio chip in social alarm frequency band 869.20-869.25 MHz. Channel spacing according to EN300-220-1 is 25kHz.

Symbol rate will be 9600bps. 2-GFSK modulation, deviation 3,25kHz. We use a receiver based on CC1120 with RX filter BW 20kHz.

Currently we are using CC1120 transmitter in this band and we have already certified products with it. But we want to know if CC1101 will be as good as CC1120.

Will it be possible to pass certification (EN300-220) for transmitter with CC1101? The most interesting part will be to know about ACP.

//Konstantin

over 9 years ago

0 PM over 9 years ago

TI__Mastermind 27145 points

Hi,
Please refer to the Spurious emissions in Table-10 (RF Transmit Section) of CC1101.
Thanks,PM

0 Konstantin Bilozor over 9 years ago in reply to PM

Prodigy 135 points

Hey,
Spurious emissions are not the problem. As suggested per "For compliance with modulation bandwidth requirements under EN 300 220 in the 863 to 870 MHz frequency range it is recommended to use a 26 MHz crystal for frequencies below 869 MHz and a 27 MHz crystal for frequencies above 869 MHz." we are using crystal 26 MHz.
In social alarm band channel spacing is 25kHz. I am concerned about ACP measurements, will it be fine or not.
//Konstanitn

0 TER over 9 years ago in reply to Konstantin Bilozor

TI__Guru**** 317180 points

- Why do they want to switch from CC1120 to CC1101?
- Not sure if we have measurement data on this. CC1120 has better ACP and is a narrow band device compared to CC1101
- Which output power do they want to use? I can see if we will be able to do a quick measurement.

0 Konstantin Bilozor over 9 years ago in reply to TER

Prodigy 135 points

We want to use 10dBm output power. It would be perfect if you can provide measurement results.

0 TER over 9 years ago in reply to Konstantin Bilozor

TI__Guru**** 317180 points

I did a quick measurement: https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/156/cc1101_5F00_acp.WMF

0 Konstantin Bilozor over 9 years ago in reply to TER

Prodigy 135 points

Thanks for reply, TER!

Is this unmodulated carrier? How does it look like when you apply 2-GFSK modulation, 3,25kHz deviation and 9,6k baud rate, will it still be within the limits?

//Konstanitn

0 TER over 9 years ago in reply to Konstantin Bilozor

TI__Guru**** 317180 points

https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/156/4010.cc1101_5F00_acp.WMF

0 Konstantin Bilozor over 9 years ago in reply to TER

Prodigy 135 points

Thanks for measurement, TER!

Based on your measurement there will be no problems with certification, correct?

Please, see my measurement below. With CC1101 and same settings, delta between M1 and D2 is 12,58kHz and 25dB. My measurement differs from yours and I wonder, what can be the reason?

//Konstantin

0 TER over 9 years ago in reply to Konstantin Bilozor

TI__Guru**** 317180 points

When measuring ACP the power is measured in given bandwidths, see section 7.6 in www.etsi.org/.../en_30022001v020401o.pdf. The measurement is not a delta as you have done. Check if your spectrum has ACP as built-in measurement method.

0 Konstantin Bilozor over 9 years ago in reply to TER

Prodigy 135 points

Yes, I understand that this is not delta measurement.
I wanted to highlight difference between your measurement and my measurement.
Bandwidth in your case seems to be lower. I wanted to know, what is the reason?
In your opinion, is it something what we can go with further, with CC1101? Or we throw it away and make new design?

0 TER over 9 years ago in reply to Konstantin Bilozor

TI__Guru**** 317180 points

Try a lower RBW, the OBW is 10.5 kHz for this datarate/ deviation (9.6 kbps/ 3.25 kHz) and 3 kHz is too much to measure this accurately.

You plot looks too wide, please recheck your settings.

0 Konstantin Bilozor over 9 years ago in reply to TER

Prodigy 135 points

I was using the same settings as you, you had RBW 3kHz. But results are different. Can this difference be caused by external HW?

0 TER over 9 years ago in reply to Konstantin Bilozor

TI__Guru**** 317180 points

No, the OBW is set mainly by the datarate, deviation and modulation format. Do you use SmartRF Studio to set up your device?

0 Konstantin Bilozor over 9 years ago in reply to TER

Prodigy 135 points

Yes, I use SmartRF Studio.
Signal settings were the same as I wrote in the first message.
Spectrum Analyzer settings were the same as you were using. For this measurement you were using RBW 3kHz, as I see from your screenshots. I was using the same. Why you suggest to lower it for me, however you did not do it?

0 TER over 9 years ago in reply to Konstantin Bilozor

TI__Guru**** 317180 points

Could you send a SmartRF Studio xml config file with the settings you use and I can test with those?

0 Konstantin Bilozor over 9 years ago in reply to TER

Prodigy 135 points

We have custom register settings. First we exported the setting from SmartRF Studio and then some registers were modified manually. So, unfortunately, we do not have xml config file.

Maybe you can send me your xml config file and I can compare them with settings I have?

//Konstantin

0 TER over 9 years ago in reply to Konstantin Bilozor

TI__Guru**** 317180 points

I used one of the standard settings in SmartRF Studio and changed the datarate and deviation to what you use.

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CC1101 compliance with EN300-220-1