Electronic – What are the use cases for a closed solder jumper on a PCB

How about this document about antenna design for the PN512? The rectangular antenna on page 47 looks like it will meet your needs.

Texas instruments also makes some fairly decent HF antenna design guides.

I've fabricated some of these rectangular antennas for 13.56MHz NFC before (the ones specified by TI), they're fairly simple and work well as can be expected.

Copper pour has a couple of functions:

1. Create power & ground planes. These can improve the performance of PCB containing high speed signals. I'm guessing that high speed signals are not a part of your design. Anywhere you're not going to be able to do this without considerable re-layout of your design, probably moving most of the components on the underside onto the top side.

2. Improve etching. Firstly, having large pour areas (even if they are not connected to anything) reduces the amount of etchant that's used up in the etching process. This means you have to replace the etchant less often, and saves money.

3. Improve etching again. If you're etching the board yourself, you may notice that the board doesn't etch evenly across its surface. Large areas with no copper are using up the etchant more than areas with lots of copper. This makes the etchant weaker in those areas. By adding hatched copper fill across the board means the copper density varies less, and so it etches more evenly.

So my advice would be:

• If you're etching it yourself, then add copper pour connected to nothing.
• If your having it etched by a company, then leave the board without a pour.