US4631504A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Impedance conversion transformer
Assignee: SMK Corp
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Filing: 1984-11-20
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Granted: 1986-12-23
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Expires: 2004-11-20
Abstract
Abstract An impedance conversion transformer which comprises a ferrite core and a pair of coils wound about the ferrite core. The ferrite core has permittivity which reduces in proportion to increase in frequency within a band used and the pair of coils are wound in a bifilar arrangement so that the electric length of the coils becomes half-wave length. One of the coils has the opposite terminals electrically connected to each other and grounded and impedance variation and balanced to unbalanced conversion are achieved between the opposite terminals of the other coil.
Inventors
- 👤 Takeshi Matsuda
- 👤 Harumi Kano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:43
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/42
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
98 words
An impedance conversion transformer comprising: a ferrite core having a permeability which reduces in proportion to an increase in frequency within a frequency band used; and a pair of coils wound about said ferrite core in a bifilar arrangement so that the electric length of each of said coils is a half-wave length for each frequency within said band used, with one of said coils having the opposite terminals thereof being electrically connected to each other and grounded and with the impedance conversion and balanced to unbalanced conversion being achieved between the opposite terminals of the other coil.
Claim 2
Dependent Claim
98 words
An impedance conversion transformer comprising: a ferrite core having a permeability which reduces in proportion to an increase in frequency within a frequency band used; and a pair of coils wound about said ferrite core in a bifilar arrangement so that the electric length of each of said coils is a half-wave length for each frequency within said band used, with one of said coils having the opposite terminals thereof being electrically connected to each other and grounded and with the impedance conversion and balanced to unbalanced conversion being achieved between the opposite terminals of the other coil.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-22 | 1990-06-23 | 1990-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-22 | 1994-06-23 | 1994-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-22 | 1998-06-23 | 1998-12-23 | $7700.00 | Window Closed / Lapsed |