US4453145A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Band pass filter
Assignee: Telefunken Systemtechnik AG
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Filing: 1982-09-21
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Granted: 1984-06-05
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Expires: 2002-09-21
Abstract
Abstract A band-pass filter circuit has series elements, comprising a parallel resonant circuit and a first inductance, and shunt elements comprising a series resonant circuit and a second inductance, the resonant circuits comprising variable capacitances to permit variation of the frequency over a frequency band. The second inductance may be a transformer. The variable capacitances may be constituted by a plurality of switchable component capacitances, having switches connected between the capacitances and ground.
Inventors
- 👤 Harald Schuster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:28
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/01; H03H7/17; H03H7/1741; H03H7/1783; H03H7/0115; H03H7/1791; H03J; H03J5/00; H03J5/24
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
53 words
A band-pass filter comprising series elements and shunt elements, said series elements comprising a parallel resonant circuit and a first inductance means, said shunt elements comprising a series resonant circuit and a second inductance means, and said resonant circuits comprising variable capacitance means, whereby the frequency may be varied over a frequency band.
Claim 2
Dependent Claim
53 words
A band-pass filter comprising series elements and shunt elements, said series elements comprising a parallel resonant circuit and a first inductance means, said shunt elements comprising a series resonant circuit and a second inductance means, and said resonant circuits comprising variable capacitance means, whereby the frequency may be varied over a frequency band.
Claim 3
Dependent Claim
18 words
A band-pass filter as claimed in claim 1, said variable capacitance means being settable in a stepwise manner.
Claim 4
Dependent Claim
18 words
A band-pass filter as claimed in claim 2, said variable capacitance comprising a plurality of switchable component capacitances.
Claim 5
Dependent Claim
16 words
A band-pass filter as claimed in claim 3, said component capacitances being stepped in binary manner.
Claim 6
Dependent Claim
27 words
A band-pass filter as claimed in claim 1 and comprising an input and an output, said series elements being arranged between said input and said shunt elements.
Claim 7
Dependent Claim
43 words
A band-pass filter as claimed in claim 5, said parallel resonant circuit comprising third inductance means and said series resonant circuit comprising fourth inductance means, the value of said first inductance means being large relative to the values of the other inductance means.
Claim 8
Dependent Claim
20 words
A band-pass filter arrangement comprising a plurality of band-pass filter as claimed in claim 6 connected to a single source.
Claim 9
Dependent Claim
17 words
A band-pass filter as claimed in claim 1, said second inductance means being constituted by a transformer.
Claim 10
Dependent Claim
28 words
A band-pass filter as claimed claim 8, said transformer having a primary winding and a secondary winding, each of said windings having a respective terminal coupled to ground.
Claim 11
Dependent Claim
20 words
A band-pass filter as claimed in claim 9, said parallel resonant circuit being connected between said primary winding and ground.
Claim 12
Dependent Claim
43 words
A band-pass filter as claimed in claim 10, the variable capacitance means of said parallel resonant circuit comprising a plurality of component capacitances, and having switching means for switching said component capacitances, said switching means being arranged between said component capacitances and ground.
References Cited (Backward Citations)
US1850146A
Cited
US4369416A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-05 | 1987-12-05 | 1988-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-05 | 1991-12-05 | 1992-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-05 | 1995-12-05 | 1996-06-05 | $7700.00 | Window Closed / Lapsed |