Title:
ANTENNA COIL AND TRANSPONDER
Document Type and Number:
WIPO Patent Application WO/2005/069316
Kind Code:
A1
Abstract:
An antenna coil, etc. for vehicle use that can cope with miniaturization. There is provided antenna coil (10) comprising magnetic core member (1) and conductor (2) wound round the magnetic core member (1), wherein the magnetic core member (1) is constituted of a sintered ferrite comprising 54.1 to 57.5 mol% of Fe2O3, the balance substantially composed mainly of MnO and containing as accessory ingredients 60 to 800 ppm, in terms of SiO2, of Si, 600 to 4000 ppm, in terms of CaCO3, of Ca and 1500 to 4000 ppm of Co3O4. The sintered ferrite can further contain Zn. This antenna coil (10) enables enhancing of inductance as compared with that of conventional Ni antenna coils and enables reducing of the number of turns of the conductor (2), thereby realizing miniaturization of the antenna coil (10).
Inventors:
BABA FUMITAKA (JP)
MURASE TAKU (JP)
SAKANO SHINICHI (JP)
NAKANO MANABU (JP)
MURASE TAKU (JP)
SAKANO SHINICHI (JP)
NAKANO MANABU (JP)
Application Number:
PCT/JP2005/000380
Publication Date:
July 28, 2005
Filing Date:
January 14, 2005
Export Citation:
Assignee:
TDK CORP (JP)
BABA FUMITAKA (JP)
MURASE TAKU (JP)
SAKANO SHINICHI (JP)
NAKANO MANABU (JP)
BABA FUMITAKA (JP)
MURASE TAKU (JP)
SAKANO SHINICHI (JP)
NAKANO MANABU (JP)
International Classes:
H01F1/34; H01F1/37; H01Q1/22; H01Q7/08; (IPC1-7): H01F1/34; H01F1/37; H01Q7/08
Foreign References:
| JP2000173841A | 2000-06-23 | |||
| JP2002246828A | 2002-08-30 | |||
| JPH0653023A | 1994-02-25 | |||
| JPH07130527A | 1995-05-19 |
Attorney, Agent or Firm:
Oba, Mitsuru (8F KM Building, 4-3, Iwamotocho 1-chom, Chiyoda-ku Tokyo 32, JP)
Download PDF: