US 4,931,807 AGranted

Non-stationary antenna with sleeve and resonant circuit

AssigneeNippon Tsushin Densen Company, Ltd.

InventorKatsumi Naitou

Life of this patent

Estimating the term…

Loading patent…

Abstract

Disclosed is a non-stationary antenna whose characteristics are guaranteed free of the surrounding variables, such as configuration of the land, electrically conductive condition of the earth's surface, buildings of different heights or climatic changes. The non-stationary antenna has upper and lower antenna conductors decoupled by the capacitors of a resonator arrangement. Thus, if the surrounding variables should cause an adverse effect on the upper antenna conductor, it cannot be transmitted to the lower antenna conductor. Also, the antenna can be bent, and can be held in the bending position until it is straightend with hands. Thus, no matter what posture an associated wireless may take, the antenna can be bent so as to take a vertical posture, which is most appropriate for radiating or receiving electromagnetic waves.

Claims3

Dependent claims

A non-stationary antenna, comprising:

a central antenna conductor having an upper antenna section and a lower antenna section, a part of said lower antenna section including a coaxial cable having an inner conductor and an outer sheath, said outer sheath having first and second ends;
a cylindrical metal sleeve encircling said lower antenna section;
said first end of said outer sheath of said coaxial cable not being electrically connected to any other elements and said second end of said outer sheath of said coaxial cable being connected to said cylindrical metal sleeve;
a resonator circuit arrangement placed in said lower antenna section, said resonator circuit arrangement including a plurality of parallel connected resonator circuits, each resonator circuit comprising a coil and a capacitor bank connected in series, each capacitor bank including a variable capacitor and a non-variable capacitor connected in parallel, said resonator circuit arrangement being an only electrical connection between said upper antenna section and said lower antenna section.

1 more element

Dependencies are inferred from the claim text.