| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem of difficulty in obtaining excellent communication environment caused by low radiation efficiency of a short type dipole antenna required in the case of lacking space for installation of an antenna in an area where houses are densely packed or the like because the length of the dipole antenna used for radio communication is about 1/2λ.SOLUTION: There is provided an antenna for radio communication comprising a radiator, and two different spiral, swirl-like, or concentric circular conductors A and B connected to an end point radiator on the inside. The numbers of turns of the conductors A and B are set so that impedance determined by viewing the antenna from a power supply point, which is the center point of the radiator, resonates with a specific radio communication frequency. Thereby, the antenna can minimize loss by requiring no loading coil without reducing radiation resistance more than necessary even when the whole length of the antenna is short. |
