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I am designing a PCB that will require a GNSS antenna. The antenna will feed directly into a GNSS module located on the same board. It seems a popular antenna choice for this is a ceramic patch antenna.

For example, this Abracon antenna seems like it would work well for me.

I am a bit confused on how this antenna is actually supposed to attach to a circuit board.

Is the only electrical connection that this antenna makes with the PCB from the through hole post near the center of the antenna? Does the antenna require an electrical connection to the ground plane on my PCB somehow, or does the ground plane on my PCB under the antenna become an integral part of the antenna, thus not requiring a direct connection to the patch anywhere?

I have looked at several other similar antennas and their associated documentation and haven't been able to come to a conclusion. I am looking for some extra guidance on how to design this antenna into my PCB.

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In my experience using these devices (not designing) the antenna is only connected to the rf feed, not the ground plane. In addition there is a large ground plane provided under the antenna, and the antenna is glued or adhesive taped down.

Note that these observations are alluded to in the data sheet you linked:

enter image description here

Ultimately the best bet is to contact the manufacturer for layout guidelines. If they offer a sample assembly there might be cad files you can poach the layout best practices from as well

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  • \$\begingroup\$ ah, even specs for thje ground plane, thoughh I'm somehow missing a unit for 15×15. Centimeter seems very generous, millimeter too small. \$\endgroup\$ May 27 at 14:30
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    \$\begingroup\$ It’s a 13x13 mm antenna and these ceramics are almost magical! I would bet that 15mm is “enough” to achieve rated performance, and anything more will be gravy \$\endgroup\$
    – Bryan
    May 27 at 14:34
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Abracon has Application Notes for antennas: https://abracon.com/resources/?&section=applicationNotes?&line=48090?&type=13940

You'll want to read the "Antennas for High-Precision GNSS Applications" note. It tells you that

Abracon’s internal passive stacked patch solutions can be mounted on the metal plane, which acts as ground using the through-hole pin and adhesive tape. The pin can be soldered to the feedline on the back side of the PCB

So, you PCB contains the ground plane, and the pin extends through the board to the feed line on the other side of the antenna. And that's it! No other electrical connection.

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The C (xxx pF) coupling between metal planes is low enough impedance if done with minimal gap.

Otherwise with no gnd plane under antenna, both are needed to couple the signal.

This is adequate for most signal antenna in the 1 to 10 GHz range.

The gnd plane geometry ought to be >100:1 width:gap ratio for good coupling.

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