Planar printed-circuit-board transformers with effective electromagnetic interference (EMI) shielding

Patent 6501364 Issued on December 31, 2002. Estimated Expiration Date:

June 15, 2021. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

3866086

Planar inductors
Patent #: 4494100
Issued on: 01/15/1985
Inventor: Stengel , et al.

Plasma ignition system for an internal combustion engine
Patent #: 4510915
Issued on: 04/16/1985
Inventor: Ishikawa , et al.

Planar coil magnetic transducer
Patent #: 4613843
Issued on: 09/23/1986
Inventor: Esper , et al.

Transformer coupled power switching circuit
Patent #: 4748532
Issued on: 05/31/1988
Inventor: Commander , et al.

Shielding material and shielded room
Patent #: 4890083
Issued on: 12/26/1989
Inventor: Trenkler, et al.

Inductance and capacitance noise filter
Patent #: 5039964
Issued on: 08/13/1991
Inventor: Ikeda

Noise filter
Patent #: 5431987
Issued on: 07/11/1995
Inventor: Ikeda

Flat transformer and power supply unit having flat transformer
Patent #: 5502430
Issued on: 03/26/1996
Inventor: Takahashi, et al.

Transformer device
Patent #: 5579202
Issued on: 11/26/1996
Inventor: Tolfsen, et al.

More ...

Inventors

Assignee

City University of Hong Kong

Application

No. 883145 filed on 06/15/2001

US Classes:

336/200, Printed circuit-type coil336/223, Having conductor of particular shape (e.g., tapered longitudinally or of noncircular cross section)336/232Planar type

Examiners

Primary: Mai, Anh

Attorney, Agent or Firm

Merchant & Gould P.C.

Foreign Patent References

0 147 499 EP. 07/10/1985
54-110424 JP. 08/10/1979
4-10680 JP. 01/10/1992
6013247 JP. 01/10/1994
200111651 JP. 04/10/2012

International Class

H01F 005/00

Abstract

Novel designs for printed circuit board transformers, and in particular for coreless printed circuit board transformers designed for operation in power transfer applications, are disclosed in which shielding is provided by a combination of ferrite plates and thin copper sheets.

Other References

Tang et al., "Coreless planar printed-circuit-board (PCB) transformers--A fundamental concept for signal and energy transfer," IEEE Transactions on Power Electronics, vol. 15, No. 5, pp. 931941 (Sep. 2000)
Hui et al., "Coreless printed-circuit board transformers for signal and energy transfer," Electronics Letters, vol. 34, No. 11, pp. 1052-1054 (May 1998)
Hui et al., "Some electromagnetic aspects of coreless PCB transformers," IEEE Transactions on Power Electronics, vol. 15, No. 4, pp. 805-810 (Jul. 2000)
Onda et al., "Thin type DC/DC converter using a coreless wire transformer," IEEE Power Electronics Specialists Conference, pp. 1330-1334 (Jun. 1994)
Coombs, C.F., "Printed Circuits Handbook," 3rd Ed. McGraw-Hill, p. 6.32 (1998). No month
Tang et al., "Characterization of coreless printed circuit board (PCB) transformers," IEEE Transactions on Power Electronics, vol. 15, No. 6, pp. 1275-1282 (Nov. 2000)
Paul, C.R., Introduction to Electromagnetic Compatibility, Chapter 11--Shielding, pp. 632-637 (1992), no month
Tang et al., "A low-profile power converter using printed-circuit board (PCB) power transformer with ferrite polymer composite," IEEE Transactions on Power Electronics, vol. 16, No. 4, pp. 493-498 (Jul. 2001)
Hui et al., "Coreless PCB based transformers for power MOSET/IGBT gate drive circuits," IEEE Power Electronics Specialists Conference, vol. 2, pp. 1171-1176 (1997). No month
Bourgeois, J.M., "PCB Based Transformer for Power MOSFET Drive," IEEE, pp. 238-244 (1994). No month
Goyal, R., "High-Frequency Alalog Integrated Circuit Design," pp. 107-126 (1995). No mont