I am currently designing a board with a PCB trace NFC-antenna and spent some time trying to figure out a good shape of the antenna.
ST has a nice tool in their eDesignSuite to calculate the inductance based on the size and number of turns. But if you end up with a lot of turns it can be quite boring to draw the antenna yourself, so I made a tool for it. Could have done it in any language but ended up using javascript since it can be used directly in the browser.
Behold, the NFC Antenna Generator. It generates a footprint in any resolution that can easily be imported in KiCad or similar. Enjoy!
