Double omni-directional antenna

US3945013A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Anton Brunner · Starnberg, DE
• Nikolaus Willburger · Olching, DE

Key dates

• Filing date: Oct 23, 1974
• Grant date: Mar 16, 1976
• Expiry date: Oct 23, 1994

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01Q5/50
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

A double omni-directional antenna for use with a transponder is disclosed allowing simultaneous operation within two different frequency bands. A double coaxial line is provided having outer, central, and inner concentric conductors. The outer and central conductors form a coaxial feed for a lower frequency antenna and the central and inner connectors form a coaxial feed for a high frequency antenna. The higher frequency antenna is located directly above the lower frequency antenna and each is either a unipole for vertically polarized radiation or a slot radiator for horizontally polarized radiation.