ANTENNA DEVICE WITH GROUNDING WIRE ELEMENT

摘要

PROBLEM TO BE SOLVED: To improve the antenna strength and to obtain an excellent characteristic equal to that when a grounding wire element and an antenna support are directly connected. SOLUTION: A power feeding coaxial line 14 is connected to a radiation element 18 and an antenna support 11 is provided at the outside. A sleeve 10 whose the length is aboutλ(wavelength)/2 is inserted between the antenna support 11 and the power feeding coaxial line 14 and its lower end is fitted to the antenna support 11 by using a short-circuit metallic fixture 31. A center conductor 12 of the power feeding coaxial line 14 is led out externally from the vicinity of an upper end and fitted to the sleeve 10 by using a mount metallic fixture 15. Moreover, this antenna device is provided with a radiator cover 19 consisting of an insulating material covering a part or all of the radiation element 18 and the antenna support 11. A belt-like metallic fixture 21 coupling capacitively with the antenna support 11 is provided to the outside of the radiator cover 19 along an outer circumferential face of an end of the antenna support 11 and plural ground wire elements 20 are mounted to the belt-like metallic fixture 21.