[RF] 天線好文

https://physics.stackexchange.com/questions/326727/how-can-an-antenna-pick-up-thousands-of-frequencies-at-the-same-time

http://120.101.8.4/lyhsu/database/grade/%E9%82%B1%E5%BB%BA%E6%96%87/%E6%89%8B%E6%8C%81%E8%A3%9D%E7%BD%AE%E5%A4%A9%E7%B7%9A%E8%A8%AD%E8%A8%88Ch2-RF%E6%A6%82%E5%BF%B5%E8%88%87%E5%A4%A9%E7%B7%9A.pdf