https://blog.wongcw.com/2020/03/02/fcc%e6%8a%95%e7%a5%a8%e9%80%9a%e9%81%8e3-7ghz-3-98ghz%e9%a0%bb%e6%ae%b5%e5%88%86%e9%85%8d%e7%94%a8%e6%96%bc5g%e6%9c%8d%e5%8b%99/