BG77 GPS antenna circuit for onboard antenna

Hi, I am trying to design a GPS antenna circuit for animal/cattle tracking.

  1. I am using BG95 LTE/GPS modem.
  2. ANT_GNSS goes to modem antenna pin.
  3. Using SKY65723 RF front end chip which has built in SAW + LNA + SAW and matching
  4. C33 will be removed during antenna tuning.
  5. J3 is SMA connector for antenna tuning during testing. Will be removed during production.
  6. R19, R20, R21 is pi matching network to be decided during antenna tuning before production.
  7. Using W3011A ceramic chip antenna from pulse electronics.

Any comments and suggestions appreciated.

Do you need additional LNA? Connecting ANT_GNSS directly to C33 should work fine.
What is the purpose of C31 and C33?
You have default values for R19 and R21 specified as 0R, but they should be NI or NM or however you call the situation when they are not populated.
I’d go for Passive antenna design (solution 1) as specfied in BG77 Reference design document. We use W3011A this way (but with different GNSS module).

The design looks good. But the important part is on the PCB RF layout. I suggest you send the design to Quectel Local FAE or support team (support@quectel.com) for a free design checking. Thanks.

Hi winston ,

we have no datasheet of sky56723 and W3011A ,without enough info , We can’t guarantee that the antenna can work in the linear amplification area instead of the saturation area .

I enclosed one mature design for BG95 GNSS antenna for your reference ,

As Rachel said , the best way is that , send your sch and PCB layout to

support@quectel.com , it will be assigned to professional expert , they will review your design and modify it .