知识与财富的链接
介绍了一种新型的宽频带双极化辐射单元,该辐射单元采用了新型的电磁带隙(electromagnetic bandgap,EBG)结构加载,该EBG结构结合对称振子进行一体化设计,缩小了辐射单元的高度,其高度约为中心频率的0.16个波长.利用这种辐射单元组阵,形成四单元基站天线.HFSS仿真结果表明,在1.71-2.69 GHz频段内,该辐射单元的电压驻波比(voltage standing wave ratio,VSWR)小于1.5,隔离度大于22 dB.同时,组阵后的四单元基站天线辐射参数良好,水平面半功率波束宽度58.1°-72.1°,轴向交叉极化比大于21 dB,前后比大于20 dB,基本能够满足移动通信对基站天线的使用要求.
Micro-culture is an emerging cultural phenomenon in recent years. At present, the academic research on micro-culture is gradually developed, and lots of achievements about the source, connotation, characteristics of the term, the influence of micro-culture and development countermeasures are published. However, as a new cultural expression means, the research about micro-culture has further space of expansion, such as the systematicness of micro-culture and the holistic research needs to be strengthened; the relationship between culture and other cultures is weak; Both the carrier of the transmission of micro-culture and the process of its spreading the discourse transformation of ideological and political education need to be studied, and the empirical research also needs to be strengthened.