I'm integrating an nRF24L01+ chip into a PCB I'm designing, but I'm a little confused about the best PCB antenna design. In the datasheet for the chip, they specify an antenna like this:
However, all of the boards you can buy with this chip use a different design:
The design is quite different. Not only is it a different shape, it also has that extra stub track with a via.
What is the reason they do this? Is it a more effective antenna, or does it just take up less PCB space?
If it is a superior design, how can I create my own? Do I just draw a wiggly line that looks roughly similar, or do I have to get the dimensions precise for it to work properly?