QUESTION

Question

According to the datasheet  SR4L002  Average efficiency is about 60% at 868 mhz band.  so is it possible to achieve better efficiency with single band matching for the SR4L002 antenna for 868 mhz ISM band ?

We have the equipment and experience to design the matching circuit. However, I want to make sure whether this is possible during the design phase.

Answer 1

Hi Sir,

it may improve the efficiency with single band matching for 868MHz ISM band, but not be improved significantly due to the antenna efficiency for sub-GHz frequency is much relied on the PCB dimension (length).

For ISM band application, we have a solution Gatun - SR42I110, which has better efficiency at 868MHz.

Comments

Hi Raymong

we changed our design to SR4I052,   Gatun - SR42I110 seems a bit better but it is not available in global stocks.

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Hi Sir,

I believe the Gatun is available now.  let us check the stock internally.
How many quantity you need for your sample build?

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Hi

do you think gatun is a better choice than SR4I052 ? 

sample production needs 150 qty. 

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Hi Sir,

do you mind telling what the PCB size is?
if the PCB size is large ( same as Velox EVB dimension), then the performance will be similiar.

however, Gatun has better performance when the PCB length is reduced.

we have few thousand samples in stock, and you can request the sample in Antenova Website.

thanks

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the pcb size is 82x43 mm, antenna is located long end of the pcb. 

However, there is a 1-meter-long cable that extends down from the PCB. That cable has a 3x0.35mm ground wire. I'm not sure, but could that long ground cable also act as an additional counterpoise ?

i will also tune the matching circuit centered to the 868 mhz to have better efficiency.  By the way, ignore these header pins. They will not be there in production.

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Hi Sir,

thanks for your information.  the placement looks fine.

the ground wire in the cable can be treated as ground extension, however, it may not work as good as a solid ground plane.