| 摘要 |
An adjustable monopole antenna apparatus and methods. In one embodiment, the antenna apparatus is intended for mobile terminals. In an exemplary implementation, there is an adjusting point is provided, from which a conductor is branched to an adjusting circuit. The adjusting circuit comprises a switch and alternative reactive elements connected to ground, selectable by the switch. When a reactive element is changed, the electric length and resonance frequency of the radiator change, and the corresponding operating band shifts. If the antenna is configured as a dual-band antenna, the above-mentioned operating band is the lower band. One or more higher operating bands are based e.g. on radiating slots implemented by the same radiator conductor. The operating band of the exemplary embodiment of the antenna below the frequency 1 GHz can be shifted in a wider range than in the corresponding known antennas. |
