I'm working on a 4-layer PCB that has a wifi module and a chip antenna, the antenna is placed at the corner of the PCB and the copper beneath it is removed, I see that via fences are used on the breakout board of the same module, but the reference design doesn't say much about it, so I was wondering how they work ? how many via do I need ? their placement, sizes and the spaces between them ?
This is the breakout board
This is my current design
Edit: This is the reference design for the module
In addition to the references in the answer, I've also found a paper that mentions via fences in RF design, and has some evaluation of different layouts, High Density RF Loadboard Design section 4.3. Ground Via Shielding Evaluation
Also, I've calculated the spacing between the vias for 2.4GHz to be around 100mils.