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US 6,472,957 B1Granted
Low power switchable filter tuner
AssigneeZenith Electronics Corporation
InventorPierre Dobrovolny
Life of this patent
Estimating the term…
Abstract
A switchable filter for passing one of a plurality of frequency bands has n bandpass filter sections coupled in parallel between a filter input terminal and a filter output terminal. Each of the n bandpass filter sections is arranged to pass a different frequency band. Each of n switches is coupled to a respective one of the n bandpass filter sections, and each of the n switches is operable in either an OFF state for activating a corresponding one of the n bandpass filter sections or an ON state for deactivating the corresponding one of the n bandpass filter sections. The n switches are arranged and controlled so that, when any one of then switches is operated to its off state, the remaining n−1 switches are operated to their ON states and form a series circuit for conducting a common current.
Claims35
A switchable filter for passing one of a plurality of frequency bands comprising:
- a filter input terminal;
- a filter output terminal;
- n bandpass filter sections, wherein each of the n bandpass filter sections is coupled between the filter input terminal and the filter output terminal, and wherein each of the n bandpass filter sections is arranged to pass a different frequency band;
- n switches each coupled to a respective one of the n bandpass filter sections, wherein each of the n switches is operable for assuming either an OFF state for activating a corresponding one of the n bandpass filter sections or an ON state for deactivating the corresponding one of the n bandpass filter sections, wherein the n switches are arranged and controlled so that, when any one of the n switches is operated to its OFF state, the remaining n−1 switches are operated to their ON states and form a series circuit for conducting a common current, and wherein n≧3.
1 more element
A switchable filter for passing one of a plurality of frequency bands comprising:
- a filter input terminal;
- a filter output terminal;
- at least first, second, and third bandpass filter sections, wherein each of the at least first, second, and third bandpass filter sections is coupled between the filter input terminal and the filter output terminal, and wherein each of the at least first, second, and third bandpass filter sections is arranged to pass a different frequency band;
- at least first, second, and third switches, wherein the first switch is coupled in controlling relationship to the first bandpass filter section, wherein the second switch is coupled in controlling relationship to the second bandpass filter section, and wherein the third switch is coupled in controlling relationship to the third bandpass filter section;
- and,
- a controller coupled to the at least first, second, and third switches, wherein the controller is arranged to control the first switch to an OFF state so that the first bandpass filter section is activated and to control the second and third switches to ON states so that the second and third switches conduct in series so as to deactivate the second and third bandpass filter sections, wherein the controller is arranged to control the second switch to an OFF state so that the second bandpass filter section is activated and to control the first and third switches to ON states so that the first and third switches conduct in series so as to deactivate the first and third bandpass filter sections, and wherein the controller is arranged to control the third switch to an OFF state so that the third bandpass filter section is activated and to control the first and second switches to ON states so that the first and second switches conduct in series so as to deactivate the first and second bandpass filter sections.
3 more elements
A switchable filter for passing one of a plurality of frequency bands comprising:
- a filter input terminal;
- a filter output terminal;
- a first bandpass filter section coupled between the filter input terminal and the filter output terminal, wherein the first bandpass filter section is arranged to pass a first frequency band;
- a second bandpass filter section coupled between the filter input terminal and the filter output terminal, wherein the second bandpass filter section is arranged to pass a second frequency band;
- a third bandpass filter section coupled between the filter input terminal and the filter output terminal, wherein the third bandpass filter section is arranged to pass a third frequency band;
- a fourth bandpass filter section coupled between the filter input terminal and the filter output terminal, wherein the fourth bandpass filter section is arranged to pass a fourth frequency band, wherein the first, second, third, and fourth frequency bands are different;
- a first switch coupled to the first bandpass filter section;
- a second switch coupled to the second bandpass filter section;
- a third switch coupled to the third bandpass filter section;
- a fourth switch coupled to the fourth bandpass filter section;
- and,
- a controller coupled to the first, second, third, and fourth switches, wherein the controller is arranged to control the first switch so that the first bandpass filter section is activated and to control the second, third, and fourth switches so that the second, third, and fourth switches conduct current in series to deactivate the second, third, and fourth bandpass filter sections, wherein the controller is arranged to control the second switch so that the second bandpass filter section is activated and to control the first, third, and fourth switches so that the first, third, and fourth switches conduct current in series to deactivate the first, third, and fourth bandpass filter sections, wherein the controller is arranged to control the third switch so that the third bandpass filter section is activated and to control the first, second, and fourth switches so that the first, second, and fourth switches conduct current in series to deactivate the first, second, and fourth bandpass filter sections, and wherein the controller is arranged to control the fourth switch so that the fourth bandpass filter section is activated and to control the first, second, and third switches so that the first, second, and third switches conduct current in series to deactivate the first, second, and third bandpass filter sections.
9 more elements
Dependencies are inferred from the claim text.