So I've just completed my Inverted F Antenna (IFA) as a polygon in the brd view on Eagle, I can connect the input section quite easily with an wire.

Whilst the GND section of the IFA I'm having a bit more difficulty with. As according to the datasheet I'm following GND section on the IFA requires a via which connects to the GND. Now if I add a via and set the name to GND suddenly the part of the polygon that was situated where the polygon is disappears.

Likewise if I name the via as to the name of polygon in this case its called "ANTENNA_2.4GHZ" then the bottom layer for GND will disappear.

enter image description here


As an alternative option I have created a footprint of the IFA for an Antenna library with pads within the input and GND sections of IFA, wondering if this would work instead or if not what would I have to change on it?

Don't judge me on the symbol, will get a better one later. enter image description here


1 Answer 1


I believe making the antenna a library part would be the preferred way to go; this way you can also add rectangles in the appropriate keepout layers in order to keep the ground plane from invading your antenna.

  • \$\begingroup\$ Hi Dave, cheers for the advice. Small question about the library part. I've managed to get everything done minus the GND section. As according to the datasheet the GND needs a via to the bottom ground layer. Now do I actually need to do this? Or can I just place a smd pad and allow it to connect to the top ground layer? Because when making the footprint there's no option to place a via but instead I have to put a through hole which as you can guess is alot larger than that of a via. \$\endgroup\$ Commented Oct 3, 2018 at 19:05
  • \$\begingroup\$ Well, first of all, you can control the size of all holes you make in the board. Second, you haven't shown us the datasheet you're working from, but my assumption would be that the antenna basically needs to have a solid ground along one side as shown -- but whether that ground is in the same layer or a different layer doesn't matter much. That would mean the via is optional. You could just as well connect the feedpoint through a via and have a solid ground on the same layer as the antenna itself. \$\endgroup\$
    – Dave Tweed
    Commented Oct 3, 2018 at 20:01
  • \$\begingroup\$ The datasheet can be found here. The 2nd image in my main post is what the via question is referring to as it shows an arrow pointing to a via to GND layer. I know you can change the hole size in the board although you can't get around the exact size pad hole as you would for a via. Put exact drill and diameter and still turned out larger when it compared the antenna part on board vs a fresh via. I hope the via itself as you said is optional and that I can simply put a smd pad to represent the GND. \$\endgroup\$ Commented Oct 3, 2018 at 21:54

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