| 摘要 |
A compact multi-band antenna structure consisting of overlapping elements formed like tree rings is described. A dipole multi-band antenna includes a first arm having a first conductive cylinder with a predetermined length corresponding to a first frequency and a second conductive cylinder having a predetermined length corresponding to a second frequency positioned over the first conductive cylinder without contact between the first conductive cylinder and the second conductive cylinder. A first end of the first conductive cylinder is in the same plane as and is electrically coupled to a first end of the second conductive cylinder. A second arm is similarly formed. A feed line is coupled to the first and second conductive cylinders and to the cylinders in the second arm. Additional frequencies may be added by similarly stacking additional conductive cylinders. The structure is also applied to monopole, circular, spiral, helical and slot antennas. |
