| 摘要 |
A dielectrically-loaded loop antenna has a cylindrical dielectrical core (12), a feeder structure passing axially through the core, a sleeve balun (20) encircling one end portion of the core and helical antenna elements (10A - 10B) extending from a feed connection with the feeder structure at the other end of the core to the rim of the balun. the antenna elements (10A - 10D) are arranged as a pair of laterally opposed groups (10AB, 10CD) of conductive elongate helical elements each having at least first and second conductive elements of different electrical lengths to form a plurality of looped conductive paths. By forming at least one of the conductive elements in each group as a conductive strip with one or both edges meandered, such that the edges of the strip are non-parallel and have different electrical lengths, additional modes of resonance are created, yielding an improvement in bandwidth. |
