US3721932A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Broadband radio frequency ferrite transformer providing close coupling
Assignee: Motorola Solutions Inc
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Filing: 1971-09-14
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Granted: 1973-03-20
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Expires: 1991-09-14
Abstract
Abstract A broadband radio frequency transformer for use in the frequency range from 25 to 175 megahertz includes closely coupled windings on a ferrite rod providing low leakage inductance. A plurality of primary coils and a single continuous secondary coil are provided, with each primary coil bifilar wound with a portion of the secondary coil. The number of turns in the secondary coil is equal to the total number of turns in all the primary coils, or may be up to 50% greater than the total number of turns in the primary coils. The primary coils are connected in parallel to provide a step-up transformer having an impedance ratio related to the ratio of the number of turns in each primary coil to the number of turns in the secondary coil. The single coil can be used as the primary winding and the plurality of coils connected in parallel as the secondary winding for an impedance step-down transformer.
Inventors
- 👤 G Fierstien
- 👤 P Jacobs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:33
CPC Classifications
H; H01; H01F; H01F30/00; H01F30/06; H01F30/10
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
257 words
A broadband, closely coupled transformer for use on a printed circuit board at frequencies in the range from 25 to 175 megahertz including in combination, a ferrite rod core formed of nickel-zinc ferrite material and having low loss, first and second winding means on said ferrite rod core, means securing said winding means to said core, said first winding means including a plurality of separate coils wound on said rod core and positioned axially therealong, said second winding means including a single continuous coil wound on said rod core having a plurality of coil portions corresponding in number to the number of separate coils of said first winding means, each of said coil portions of said second winding means being wound in a bifilar relation with one of said coils of said first winding means, said continuous coil of said second winding means having a number of turns in the range from the same number of turns as the total number of turns in all said coils of said first winding means to a number 50 percent greater than the total number of turns of all said coils of said first winding means, said plurality of coils of said first winding means and said continuous coil of said second winding means all having coil ends extending in the same direction for insertion through openings in the printed circuit board for mounting the transformer on the printed circuit board, and conductor means on the printed circuit board for connecting said coils of said first winding means in parallel.
Claim 2
Dependent Claim
257 words
A broadband, closely coupled transformer for use on a printed circuit board at frequencies in the range from 25 to 175 megahertz including in combination, a ferrite rod core formed of nickel-zinc ferrite material and having low loss, first and second winding means on said ferrite rod core, means securing said winding means to said core, said first winding means including a plurality of separate coils wound on said rod core and positioned axially therealong, said second winding means including a single continuous coil wound on said rod core having a plurality of coil portions corresponding in number to the number of separate coils of said first winding means, each of said coil portions of said second winding means being wound in a bifilar relation with one of said coils of said first winding means, said continuous coil of said second winding means having a number of turns in the range from the same number of turns as the total number of turns in all said coils of said first winding means to a number 50 percent greater than the total number of turns of all said coils of said first winding means, said plurality of coils of said first winding means and said continuous coil of said second winding means all having coil ends extending in the same direction for insertion through openings in the printed circuit board for mounting the transformer on the printed circuit board, and conductor means on the printed circuit board for connecting said coils of said first winding means in parallel.
Claim 3
Dependent Claim
79 words
A transformer in accordance with claim 1 wherein said first winding means is the primary winding of said transformer and includes three separate coils each having a number of turns iN the range from one to two turns, and wherein said second winding means is the secondary winding of the transformer and has a number of turns in the range from three to four times the number of turns in each of said coils of said first winding means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-19 | 1976-09-18 | 1977-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-19 | 1980-09-18 | 1981-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-19 | 1984-09-18 | 1985-03-20 | $7700.00 | Window Closed / Lapsed |