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GB2274207B - Magnetic antenna system having independently controllable electrical field shielding and magnetic field balance - Google Patents

Magnetic antenna system having independently controllable electrical field shielding and magnetic field balance

Info

Publication number
GB2274207B
GB2274207B GB9403898A GB9403898A GB2274207B GB 2274207 B GB2274207 B GB 2274207B GB 9403898 A GB9403898 A GB 9403898A GB 9403898 A GB9403898 A GB 9403898A GB 2274207 B GB2274207 B GB 2274207B
Authority
GB
United Kingdom
Prior art keywords
magnetic
antenna system
independently controllable
controllable electrical
balance
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.)
Expired - Fee Related
Application number
GB9403898A
Other versions
GB2274207A (en
GB9403898D0 (en
Inventor
Robert Arthur Cordery
Michael Frank Hartings
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sensormatic Electronics Corp
Original Assignee
Sensormatic Electronics Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from US07/401,962 external-priority patent/US4999641A/en
Application filed by Sensormatic Electronics Corp filed Critical Sensormatic Electronics Corp
Publication of GB9403898D0 publication Critical patent/GB9403898D0/en
Publication of GB2274207A publication Critical patent/GB2274207A/en
Application granted granted Critical
Publication of GB2274207B publication Critical patent/GB2274207B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q7/00—Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
    • H01Q7/04—Screened antennas
GB9403898A 1989-09-01 1994-02-28 Magnetic antenna system having independently controllable electrical field shielding and magnetic field balance Expired - Fee Related GB2274207B (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US07/401,962 US4999641A (en) 1989-09-01 1989-09-01 Magnetic antenna system having independently controllable electrical field shielding and magnetic field balance
GB9018598A GB2236909B (en) 1989-09-01 1990-08-24 Magnetic antenna system having independently controllable electrical field shielding and magnetic field balance

Publications (3)

Publication Number Publication Date
GB9403898D0 GB9403898D0 (en) 1994-04-20
GB2274207A GB2274207A (en) 1994-07-13
GB2274207B true GB2274207B (en) 1994-10-05

Family

ID=26297551

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9403898A Expired - Fee Related GB2274207B (en) 1989-09-01 1994-02-28 Magnetic antenna system having independently controllable electrical field shielding and magnetic field balance

Country Status (1)

Country Link
GB (1) GB2274207B (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1982000378A1 (en) * 1980-07-14 1982-02-04 J Vandebult Modified loop antenna for security systems
US4326198A (en) * 1976-08-18 1982-04-20 Knogo Corporation Method and apparatus for the promotion of selected harmonic response signals in an article detection system
US4633250A (en) * 1985-01-07 1986-12-30 Allied Corporation Coplanar antenna for proximate surveillance systems
US4751516A (en) * 1985-01-10 1988-06-14 Lichtblau G J Antenna system for magnetic and resonant circuit detection
US4872018A (en) * 1987-08-31 1989-10-03 Monarch Marking Systems, Inc. Multiple loop antenna

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4326198A (en) * 1976-08-18 1982-04-20 Knogo Corporation Method and apparatus for the promotion of selected harmonic response signals in an article detection system
WO1982000378A1 (en) * 1980-07-14 1982-02-04 J Vandebult Modified loop antenna for security systems
US4633250A (en) * 1985-01-07 1986-12-30 Allied Corporation Coplanar antenna for proximate surveillance systems
US4751516A (en) * 1985-01-10 1988-06-14 Lichtblau G J Antenna system for magnetic and resonant circuit detection
US4872018A (en) * 1987-08-31 1989-10-03 Monarch Marking Systems, Inc. Multiple loop antenna

Also Published As

Publication number Publication date
GB2274207A (en) 1994-07-13
GB9403898D0 (en) 1994-04-20

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 20020824