323无线传输介质 电磁波谱 f(Hz)10910210410610910101012101410161018102010221024 Radio Microwave Infrared UV X-ray Gamma ray Visible f(Hz)10410510610710810910101011012101310141015-106 Twisted pair Satellite Fiber Coax optics Terrestrial microwave Maritime radio radio TV Band LF MF HF VHF UHF SHF EHF THF 网络和现代通信技术基础—一物理层网络和现代通信技术基础——物理层 电磁波谱 3.2.3 无线传输介质