Communications: radio wave antennas – Antennas – High frequency type loops
Patent
1997-07-03
2000-06-27
Wimer, Michael C.
Communications: radio wave antennas
Antennas
High frequency type loops
343867, H01Q 700
Patent
active
060812389
ABSTRACT:
In an electronic article surveillance system, quadrature transmitting and receiving antennas are used to improve field distribution. A transmitting antenna arrangement includes first and second adjacent co-planar antenna loops and excitation circuitry for generating respective alternating currents in the first and second loops such that the respective alternating currents are 90.degree. out of phase. In a receiving arrangement, respective signals received from two adjacent co-planar antenna loops are respectively phase-shifted by +45.degree. and -45.degree., and the resulting phase-shifted signals are summed. A far-field cancelling transmitting antenna arrangement includes four loops operated at phases of 0.degree., 90.degree., 180.degree. and 270.degree. respectively. All four loops may be co-planar, with any bucking vertical segments being horizontally displaced from each other. Alternatively, the 0.degree. and 180.degree. loops may also be arranged in a common plane that is close to and parallel with another plane in which the 90.degree. and 270.degree. loops are arranged.
REFERENCES:
patent: 2207781 (1940-07-01), Brown
patent: 4243980 (1981-01-01), Lichtblau
patent: 4251808 (1981-02-01), Lichtblau
patent: 4309697 (1982-01-01), Weaver
patent: 4373163 (1983-02-01), Vandebult
patent: 4394645 (1983-07-01), Humble et al.
patent: 4486731 (1984-12-01), Westcott
patent: 4633250 (1986-12-01), Anderson, III et al.
patent: 4634975 (1987-01-01), Eccleston et al.
patent: 4679046 (1987-07-01), Curtis et al.
patent: 4701764 (1987-10-01), Malcombe
patent: 4859991 (1989-08-01), Watkins et al.
patent: 4872018 (1989-10-01), Feltz et al.
patent: 4922261 (1990-05-01), O'Farrell
patent: 5049857 (1991-09-01), Plonsky et al.
patent: 5051726 (1991-09-01), Copeland et al.
patent: 5061941 (1991-10-01), Lizzi et al.
patent: 5081469 (1992-01-01), Bones
patent: 5126749 (1992-06-01), Kaltner
patent: 5130697 (1992-07-01), McGinn
patent: 5218371 (1993-06-01), Copeland et al.
patent: 5321412 (1994-06-01), Kopp et al.
patent: 5341125 (1994-08-01), Plonsky et al.
patent: 5373301 (1994-12-01), Bowers et al.
patent: 5387900 (1995-02-01), Plonsky et al.
patent: 5404147 (1995-04-01), Drucker et al.
patent: 5440296 (1995-08-01), Nelson
Sensormatic Electronics Corporation
Wimer Michael C.
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