QUESTION

Question

I am developping an IoT node with a LoRa (868MHz) as well as a NB-IoT (791-862MHz) transceiver. For LoRa I am planning to use the SR4C033-R and for NB-IoT the SR41I010-R antenna. I have 150x110mm space for the PCB available, I was planning to use the full space to have the largest ground plane possible and to place the two antennas in opposed corners.

Would you recommend any other configuration (both antennas on same side, smaller PCB/ ground plane)?

Answer 1

Hi Severin, Thanks for your question.

Both these antennas, as with all of our cellular antennas, work best on the short edge of the PCB. On this PCB I'd recommend SR4I010 on the 110mm edge and SR4C033 on the 150mm edge, in the corners, at 90 degrees to each other. However, if you have the option to reduce the PCB to say 150x50mm then they should be placed on the opposite short edges. We offer a free design review service which your regional Sales Representative can engage you with for a more tailored response; please contact techsupport@antenova.com to get in touch.

Thanks

Steve

Comments

Hello Steve,

thanks for the answer. Unfortunately I did not receive a reply from techsupport@antenova.com.

I have the option to reduce the PCB to 150x50mm, will this lead to better performance than 150x110mm?
Can the ground plane be "too wide" and decrease performance? It would be interesting to know what the effect of the width of the plane is, this is not described in any of the resources. Are the 115x35mm of the reference board the ideal dimensions?

Thank you

Severin

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Hi Severin,

Apologies that you didn't get a response. Can you please provide your country/region so I can get someone local to get in touch with you immediately?

In general the ground plane being too wide may not be ideal, depending on the general layout of the PCB. Just to be sure of optimum performance we would certainly recommend 150x50mm, which is a similar shape to the EVB.

Many Thanks

Steve

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Hello Steve,

thank you, my country is Switzerland.

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Hi Severin,

Many thanks, I've passed your contact details on to your regional representative.

Steve