Patent · US Expired

Planar antenna

US6700542B2 · kind B2 · utility

16Cited by
15References
40Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 15, 2002
Grant dateMar 2, 2004
Priority date
Expiry dateApr 15, 2022

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01S7/024
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

The invention is a planar antenna which comprises a plurality of antenna elements positioned relative to each other in a predetermined orientation. Each of the elements is selectively electrically connectable to one or more of the other antenna elements. A plurality of switches electrically connect the plurality of antenna elements to each other. The switches are opened and closed by a signal operating at high speed enabling the antenna to act alternately in a first antenna configuration and a second antenna configuration using the same antenna structure. Doppler signals from the first and second antenna configurations are processed to determine the direction of a person or object in relation to a door.

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