It’s a module called TinySparrow ... can submit your own PCB designs for my review! Send in your board into our tips line, with [design review] in the subject. KiCad is preferred, and a Git ...

Fortunately, there is e.g. a free KiCad library with ready-to-use PCB antenna designs to help one get started with a custom design, as well as many other resources, covered in the article.