CA2217459A1 - Eas system antenna configuration for providing improved interrogation field distribution - Google Patents
Eas system antenna configuration for providing improved interrogation field distributionInfo
- Publication number
- CA2217459A1 CA2217459A1 CA002217459A CA2217459A CA2217459A1 CA 2217459 A1 CA2217459 A1 CA 2217459A1 CA 002217459 A CA002217459 A CA 002217459A CA 2217459 A CA2217459 A CA 2217459A CA 2217459 A1 CA2217459 A1 CA 2217459A1
- Authority
- CA
- Canada
- Prior art keywords
- loops
- field distribution
- phase
- antenna configuration
- providing improved
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Variable-Direction Aerials And Aerial Arrays (AREA)
Abstract
In an electronic article surveillance system (24), quadrature transmitting and receiving antennas are used to improve field distribution.
A transmitting antenna arrangement includes first and second adjacent co-planar antenna loops (42, 44) and excitation circuitry (46) for generating respective alternating currents in the first and second loops such that the respective alternating currents are 90° out of phase. In a receiving arrangement (300), respective signals received from two adjacent co-planar antenna loops (302, 304) are respectively phase-shifted by +45° and -45° and the resulting phase-shifted signals are summed. A far-field canceling transmitting antenna arrangement includes four loops (66', 78, 68, 70) operated at phases of 0°, 90°, 180° and 270° respectively. All four loops may be co-planar, with any bucking vertical segments being horizontally displaced from each other. Alternatively, the 0° and 180° loops may also be arranged in a common plane that is close to and parallel with another plane in which the 90°
and 270° loops are arranged.
A transmitting antenna arrangement includes first and second adjacent co-planar antenna loops (42, 44) and excitation circuitry (46) for generating respective alternating currents in the first and second loops such that the respective alternating currents are 90° out of phase. In a receiving arrangement (300), respective signals received from two adjacent co-planar antenna loops (302, 304) are respectively phase-shifted by +45° and -45° and the resulting phase-shifted signals are summed. A far-field canceling transmitting antenna arrangement includes four loops (66', 78, 68, 70) operated at phases of 0°, 90°, 180° and 270° respectively. All four loops may be co-planar, with any bucking vertical segments being horizontally displaced from each other. Alternatively, the 0° and 180° loops may also be arranged in a common plane that is close to and parallel with another plane in which the 90°
and 270° loops are arranged.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US45296895A | 1995-05-30 | 1995-05-30 | |
US08/452,968 | 1995-05-30 | ||
PCT/US1996/007442 WO1996038877A1 (en) | 1995-05-30 | 1996-05-22 | Eas system antenna configuration for providing improved interrogation field distribution |
Publications (2)
Publication Number | Publication Date |
---|---|
CA2217459A1 true CA2217459A1 (en) | 1996-12-05 |
CA2217459C CA2217459C (en) | 2006-04-25 |
Family
ID=36253020
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002217459A Expired - Fee Related CA2217459C (en) | 1995-05-30 | 1996-05-22 | Eas system antenna configuration for providing improved interrogation field distribution |
Country Status (1)
Country | Link |
---|---|
CA (1) | CA2217459C (en) |
-
1996
- 1996-05-22 CA CA002217459A patent/CA2217459C/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
CA2217459C (en) | 2006-04-25 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
EEER | Examination request | ||
MKLA | Lapsed |
Effective date: 20130522 |