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US3673521A
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Equalizing transmission loss utilizing graphical method for selecting equalizer networks
Assignee: KDDI Corp
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Filing: 1971-01-11
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Granted: 1972-06-27
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Expires: 1991-01-11
Abstract
Abstract In an attenuation equalizer used to make the total transmission loss of a transmission path essentially the same for all frequencies in the range being transmitted, a desired characteristic determined for compensating a distorted frequency characteristic of the transmission path to be equalized is divided into a plurality of equilateral triangles so that each characteristic of the equilateral triangles is realized by a unit circuit, such as a constant resistance circuit of second degree function type.
Inventors
- 👤 Hiroshi Yuguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:11
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/04; H04B3/14; H04B3/141
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
183 words
A method of equalizing the transmission loss of a transmission path to make the total transmission essentially the same for all frequencies in the range of frequencies to be transmitted which comprises plotting the frequency transmission level characteristic curve of said transmission path with ordinates representing transmission level and abscissae plotted on a logrithmic scale representing frEquency, plotting a corresponding but opposite frequency attenuation equalizing curve, dividing said equalizing curve into segments by a plurality of equally spaced vertical lines, drawing a graph approximating said equalizing curve but composed of a series of connected straight lines having their junction points on said dividing lines, dividing the area between said graph and the abscissa base line into a plurality of triangles or quadrangles having their apices located on said dividing lines at equal intervals, converting said triangles or quadrangles into corresponding equilateral triangles having respectively the same areas and the same vertical heights at the same frequencies, selecting a constant resistance circuit having a frequency characteristic curve approximating each of said equilateral triangles, and connecting said circuits with one another in a cascade connection.
Claim 2
Independent Claim
183 words
A method of equalizing the transmission loss of a transmission path to make the total transmission essentially the same for all frequencies in the range of frequencies to be transmitted which comprises plotting the frequency transmission level characteristic curve of said transmission path with ordinates representing transmission level and abscissae plotted on a logrithmic scale representing frEquency, plotting a corresponding but opposite frequency attenuation equalizing curve, dividing said equalizing curve into segments by a plurality of equally spaced vertical lines, drawing a graph approximating said equalizing curve but composed of a series of connected straight lines having their junction points on said dividing lines, dividing the area between said graph and the abscissa base line into a plurality of triangles or quadrangles having their apices located on said dividing lines at equal intervals, converting said triangles or quadrangles into corresponding equilateral triangles having respectively the same areas and the same vertical heights at the same frequencies, selecting a constant resistance circuit having a frequency characteristic curve approximating each of said equilateral triangles, and connecting said circuits with one another in a cascade connection.
Claim 3
Dependent Claim
19 words
A method according to claim 1, in which said constant resistance circuits are of a second degree function type.
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) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |