dual-band 基本例句 n.双频段 For the indoor wireless communication system, a new dual-band antenna with U-shaped reflector is designed. By increasing the thickness of the air medium, the wider frequency band is achieved. 对于室内覆盖无线接收系统，提出了一种新型的基于 U型反射板的双频天线单元形式，采用厚的空气介质层以展宽带宽。 cnki