单馈电双模方形微带天线及圆极化实现

Single-feed dual-mode square microstrip antenna and realization of circular polarization

基于展开理论 ,给出了沿贴片对角线馈电时方形微带天线的内场分布和输入阻抗公式。通过在贴片四周切割缝隙 ,有效地降低了天线双主模的谐振频率并实现了圆极化辐射 ,讨论了缝隙长度与天线极化之间的关系。为实现微带天线的小型化提供了一种新途径 ,给出了

The field distribution inside antenna and the input impedance for square microstrip antenna excited along diagonal are presented by using mode expansion theory. The resonant frequencies of two dominant modes can efficently be reduced and circularly polarized radiation can easily be achieved by cutting silits in outer boundary of square patch.The relation between slit length and antenna polarization charactersistics is presented. A new approach to miniaturization of microstrip antenna is presented, and a UHF microstrip antenna is designed.