Patent · US Expired

Near isotropic circularly polarized antenna

US4958162A · kind A · utility

7Cited by
12References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 6, 1988
Grant dateSep 18, 1990
Priority date
Expiry dateSep 6, 2008

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01Q21/205
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

An antenna for transmitting and/or receiving circularly polarized (CP) electromagnetic radiation throughout a substantial portion of a sphere. A cylindrical waveguide (3,5) is associated with a transmit portion and a receive portion of the antenna, respectively. The outer surface of each waveguide (3,5) is covered with several conductive radiating patches (30,50) equidistant axially and circumferentially arranged. The patches (30,50) may be fed by elongated apertures (51,52) or by coaxial transmission line (41,42). In the former embodiment, CP is present within the waveguide (3,5), while in the latter embodiment, linear polarization is present within the coaxial transmission line (41,42). The individual patches (30,50) radiate CP in a direction normal to the patch (30,50) to produce CP in the broadside direction. The several patches (30,50) arranged in a circularly symmetric fashion working together create, by a process of constructive interference, CP axially, with opposite senses in the forward and reverse directions.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.