| 摘要 |
PURPOSE:To attain the transmission reception of a radio wave over all azimuths with a small size and to set a frequency interval by disposing a parasitic 2nd helix concentrically with a 1st helix constituting a helical antenna. CONSTITUTION:The 1st helix 1 constituting a driving helix formed by winding a conductor in spiral to the front face of a reflecting plate 3 and the spiral axis is intersected orthogonally with the reflecting plate 3. A feeder 5 is connected to a feeding terminal 4 at a prescribed feeding point. Moreover, the parasitic helix 2 formed by winding a conductor in spiral forming a parasitic helix is arranged concentrically at the outside. Since the helix sets 1, 2 are air-core coils, then the antenna is miniaturized. By, this constitution, transmission/reception of a radio wave is implemented over all azimuths and the structure parameter of the helix 2 is changed to set the mutual frequency interval adjustably. |
