Patent US781166A successfully refreshed from Google Patents.
US3671889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Broadband composite filter circuit
Assignee: Individual
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Filing: 1970-06-01
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Granted: 1972-06-20
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Expires: 1990-06-01
Abstract
Abstract A broadband composite filter circuit is disclosed which includes a plurality of filter networks, each being tuned to respond to a respective frequency bandwidth of electrical signals. Each of the filter networks is a four terminal filter network having a positive and a negative network input terminal and a positive and a negative network output terminal. The input terminals of all of the filter networks are connected in series with each other in a first predetermined order. The output terminals of all of the filer networks are connected in a series circuit with each other in a second predetermined order which is the opposite to the above mentioned first predetermined order. The input signal is then applied across the series input circuits and the output signal is derived from across the series output circuits. A switch is provided across the input terminals of each of the filter networks to enable each network to be selectively shorted out of the composite circuit to selectively vary the overall frequency response characteristic of the composite filter circuit.
Inventors
- 👤 Hollice A Favors
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:32
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/01; H03H7/09
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
335 words
A composite filter circuit comprising, in combination: a. a plurality of filter networks each having a respective input section and output section, each of said filter network having respective positive and negative network input terminals for effecting electrical connection to its input section and respective positive and negative network output terminals for effecting electrical connection to its output section and being tuned to respond to a respective frequency bandwidth of electrical signals; b. means for connecting said input terminals of said filter networks into an input circuit in which each of said input sections of said filter network is located at a different impedance level relative to a reference potential, said first means comprising means for connecting said input terminals of said filter networks in series with each other in a first predetermined order; c. second means for connecting said output terminals of said filter networks into an output circuit in which each of said output sections of said filter networks is located at an impedance level relative to said reference potential which is a compensating impedance level relative to the impedance level at which its corresponding input section is located, said second means comprising means for connecting said output terminals of said filter networks in series with each other in a second predetermined order opposite to said first predetermined order, whereby those filter networks which have their input sections located at relatively higher impedance levels, and which accordingly exhibit relatively greater gain, have their output sections located at relatively lower impedance levels, and accordingly exhibit relatively lower gain, and those filter networks which have their input sections located at relatively lower impedance levels, and which accordingly exhibit relatively lower gain, have their output sections located at relatively higher impedance levels, and accordingly exhibit relatively higher gains, all whereby compensation is provided for non-uniformity of gain caused by said different impedance levels; d. means for applying an input signal to said input circuit; and e. means for deriving an output signal from said output circuit.
Claim 2
Dependent Claim
335 words
A composite filter circuit comprising, in combination: a. a plurality of filter networks each having a respective input section and output section, each of said filter network having respective positive and negative network input terminals for effecting electrical connection to its input section and respective positive and negative network output terminals for effecting electrical connection to its output section and being tuned to respond to a respective frequency bandwidth of electrical signals; b. means for connecting said input terminals of said filter networks into an input circuit in which each of said input sections of said filter network is located at a different impedance level relative to a reference potential, said first means comprising means for connecting said input terminals of said filter networks in series with each other in a first predetermined order; c. second means for connecting said output terminals of said filter networks into an output circuit in which each of said output sections of said filter networks is located at an impedance level relative to said reference potential which is a compensating impedance level relative to the impedance level at which its corresponding input section is located, said second means comprising means for connecting said output terminals of said filter networks in series with each other in a second predetermined order opposite to said first predetermined order, whereby those filter networks which have their input sections located at relatively higher impedance levels, and which accordingly exhibit relatively greater gain, have their output sections located at relatively lower impedance levels, and accordingly exhibit relatively lower gain, and those filter networks which have their input sections located at relatively lower impedance levels, and which accordingly exhibit relatively lower gain, have their output sections located at relatively higher impedance levels, and accordingly exhibit relatively higher gains, all whereby compensation is provided for non-uniformity of gain caused by said different impedance levels; d. means for applying an input signal to said input circuit; and e. means for deriving an output signal from said output circuit.
Claim 3
Dependent Claim
250 words
The composite filter circuit of claim 1 in which: a. said plurality of filter networks comprises N filter networks, where N is any integer greater than 1; b. said means for applying an input signal comprises positive and negative circuit input terminals and said means for deriving an output signal comprises positive and negative circuit output terminals; c. said input circuit comprises a series connection of said network input terminals in which the positive input terminal of the nth filter network is connected to the negative input terminal of the (n +1)th filter network and the negative input terminal of said nth filter network is connected to the positive input terminal of the (n -1)th filter network, with the positive input terminal of the Nth filter network being connected to said positive circuit input terminal and the negative input terminal of the first filter network being connected to said negative circuit input terminal; and d. said output circuit comprises a series connection of said network output terminals in which the positive output terminal of the nth filter network is connected to the negative output terminal of the (n -1)th filter network and the negative output terminal of the nth filter network is connected to the positive output terminal of the (n +1)th filter network, with the positive output terminal of said first filter network beIng connected to said positive circuit output terminal and the negative output terminal of said Nth filter network being connected to said negative circuit output terminal.
Claim 4
Dependent Claim
25 words
The composite filter circuit of claim 2 which further includes selective means for connecting individual ones of said filter networks into said composite filter circuit.
Claim 5
Dependent Claim
33 words
The composite filter circuit of claim 3 in which said selective means comprises a respective switch for selectively shorting across the positive and negative network input terminals of each of said filter networks.
Claim 6
Dependent Claim
103 words
The composite filter circuit of claim 4 in which each of said filter networks comprises: a. an input transformer comprising a primary winding having positive and negative terminals connected to said positive and negative network input terminals, respectively, and a secondary winding having positive and negative terminals; b. an output transformer comprising a primary winding having positive and negative terminals and a secondary winding having positive and negative terminals connected to said positive and negative network output terminals, respectively; and c. a plurality of filter elements connected between said secondary winding of said input transformer and said primary winding of said output transformer.
Claim 7
Dependent Claim
80 words
The composite filter circuit of claim 5 in which said plurality of filter elements comprises first and second capacitors connected in series between said positive terminal of said secondary winding of said input transformer and said positive terminal of said primary winding of said output transformer and a third capacitor connected between the junction of said first and second capacitors and the negative terminals of said secondary winding of said input transformer and said primary winding of said output transformer.
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) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |