A method is presented to serially feed a patch and a ring antenna etched on upper surface of a first FR4 substrate. A meandered strip is etched on upper surface of a second FR4 substrate. On the bottom surface of the second substrate, there are slots cut from the ground plane. Slots are classified into two parts, the first part is associated with the patch and the second part is associated with the ring. By this way, the structure can easily be operated as a dual band circularly polarized antenna to cover both 0.915GHz and 2.45 GHz band.

可單獨使環狀天線以槽孔耦合方式激發,並可搭配貼片天線完成雙頻操作

需天線之通訊產品