Patent US4358733A successfully refreshed from Google Patents.
US4358733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spectrum analyzer without distinct band-pass filter components
Assignee: Fujitsu Ltd
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Filing: 1980-10-22
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Granted: 1982-11-09
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Expires: 2000-10-22
Abstract
Abstract In an n-band spectrum analyzer, separation of frequency bands is performed by n+1 low-pass (or high-pass) filters. The outputs of adjacent low-pass (or high-pass) filters are subtracted. The output of each subtraction circuit is smoothed by an accumulator.
Inventors
- 👤 Keishi Hanahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:51
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/16; G01R23/165; G01R23/167; G10; G10L; G10L19/00; G10L19/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
92 words
A device comprising: a plurality of filters each having separate single cut-off frequencies, said filters being arranged according to said cut-off frequencies; a plurality of squarers, each said squarer being operatively connected to a corresponding one of said filters; a plurality of subtraction circuits, each subtraction circuit having an output and having positive and negative inputs respectively, operatively connected to two corresponding adjacent ones of said squarers; and a plurality of accumulators, each of said plurality of accumulators being operatively connected to said output of a respective one of said subtraction circuits.
Claim 2
Independent Claim
92 words
A device comprising: a plurality of filters each having separate single cut-off frequencies, said filters being arranged according to said cut-off frequencies; a plurality of squarers, each said squarer being operatively connected to a corresponding one of said filters; a plurality of subtraction circuits, each subtraction circuit having an output and having positive and negative inputs respectively, operatively connected to two corresponding adjacent ones of said squarers; and a plurality of accumulators, each of said plurality of accumulators being operatively connected to said output of a respective one of said subtraction circuits.
Claim 3
Dependent Claim
36 words
The device of claim 1 wherein each of said filters is a digital filter, and further comprising: an input terminal; and an analog/digital converter, operatively connected to said input terminal and to all of said filters.
Claim 4
Dependent Claim
35 words
The device of claim 2, wherein said analog/digital converter further comprises means for receiving a clock pulse, said analog/digital converter being adapted to convert the voltage of said input terminal at each said clock pulse.
Claim 5
Dependent Claim
16 words
The device of claim 3, wherein each said accumulator further comprises means for clearing said accumulator.
Claim 6
Dependent Claim
25 words
The device of claim 4, wherein said means for clearing each said accumulator comprises an inverter connected across said accumulator, said inverter being selectively operable.
Claim 7
Dependent Claim
16 words
The device of claim 3, wherein each said accumulator further comprises means for clearing said accumulators.
Claim 8
Dependent Claim
24 words
The device of claim 6, wherein said means for clearing said accumulators comprises an inverter connected across said accumulator, said inverter being selectively actuable.
Claim 9
Dependent Claim
54 words
The device of claim 3, further comprising a plurality of accumulators respectively connected to said respective outputs of said plurality of subtraction circuits, each said accumulator comprising an output and further comprising an inverter and a coeffecient circuit in series with said inverter, said inverter and said coefficient circuit being connected across the accumulator.
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) | 1985-11-08 | 1986-05-10 | 1986-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-08 | 1990-05-10 | 1990-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-08 | 1994-05-10 | 1994-11-09 | $7700.00 | Window Closed / Lapsed |