Helical antenna device

Abstract

Abstract PURPOSE:To obtain an excellent circularly polarized wave characteristic by bending one end of a helical element conductor toward the helical center axis and prolonging the end so as to constitute a coaxial center conductor of a receptacle, inserting a dielectric, holding the center conductor with an outer conductor of the receptacle and providing a reflecting plate. CONSTITUTION:The antenna device consists of a helical element 30, the receptacle 50 and the reflecting plate 40. A terminal 31 at a feeding point of the element 30 is bent gently toward the helical center axis A-A', enters the outer conductor 51 of the receptacle 50 and becomes a center conductor 32. A hole 52 having a diameter less than the maximum diameter of the element 30 is drilled in the center of the outer conductor 51, and the hole 52 is linked to a hole 53 being a 50-ohm impedance via a section having a specific constant impedance. The holes 52, 53 are filled with ''Teflon,'' which supports the center conductor 32. The element 30 is supported in a free space, the axial symmetry of the directivity is improved, the cross polarized wave characteristic and the axis ratio are improved and stable and excellent circularly polarized wave characteristics are attained.

Inventors

• 👤 Hisao Iwasaki
• 👤 久雄 岩崎
• 👤 Kazutaka Hidaka
• 👤 一孝 日高

Bibliographic Details