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US 10,476,478 B2Granted
Tunable HF filter having series resonators
AssigneeSnapTrack, Inc.
InventorEdgar Schmidhammer
Life of this patent
Estimating the term…
Abstract
The specification relates to an RF filter in which characteristic filter variables have a decreased dependency on tuning. A filter in this case comprises series-interconnected basic elements that each have an electroacoustic resonator and impedance converters interconnected in series between the basic elements.
Claims14
A Radio Frequency (RF) filter, comprising
- a plurality of basic elements connected in series, each having an electroacoustic resonator, wherein each electroacoustic resonator is a series resonator and at least one electroacoustic resonator is tunable;
- and
- a plurality of impedance converters, each impedance converter connected in series between two basic elements, wherein the impedance converters are impedance inverters,
- wherein the at least one tunable resonator comprises a resonator element and a tunable impedance element that is interconnected in series or in parallel with the resonator element,
- wherein the RF filter is described by a symmetrical representation matrix B with Bij=Bji.
2 more elements
A Radio Frequency (RF) filter, comprising
- a plurality of basic elements connected in series, each having an electroacoustic resonator, wherein each electroacoustic resonator is a series resonator and at least one electroacoustic resonator is tunable;
- a plurality of impedance converters, each impedance converter connected in series between two basic elements, wherein the impedance converters are impedance inverters, wherein the at least one tunable resonator comprises a resonator element and a tunable impedance element that is interconnected in series or in parallel with the resonator element;
- and
- an additional impedance converter connected in parallel with a segment of the filter, wherein the segment comprises a series connection having one of the plurality of basic elements and two of the plurality of impedance converters connected in series on either side of the basic element.
1 more element
A Radio Frequency (RF) filter, comprising
- a plurality of basic elements connected in series, each having an electroacoustic resonator, wherein each electroacoustic resonator is a series resonator and at least one electroacoustic resonator is tunable;
- and
- a plurality of impedance converters, each impedance converter connected in series between two basic elements, wherein the impedance converters are impedance inverters, wherein the at least one tunable resonator comprises a resonator element and a tunable impedance element that is interconnected in series or in parallel with the resonator element,
- wherein a capacitive element is interconnected in parallel with two of the series-interconnected basic elements.
1 more element
A Radio Frequency (RF) filter, comprising
- a plurality of basic elements connected in series, each having an electroacoustic resonator, wherein each electroacoustic resonator is a series resonator and at least one electroacoustic resonator is tunable;
- and
- a plurality of impedance converters, each impedance converter connected in series between two basic elements, wherein the impedance converters are impedance inverters, wherein the at least one tunable resonator comprises a resonator element and a tunable impedance element that is interconnected in series or in parallel with the resonator element,
- wherein at least one of the plurality of impedance converters comprises two parallel capacitive elements and one parallel inductive element.
1 more element
A Radio Frequency (RF) filter, comprising
- a plurality of basic elements connected in series, each having an electroacoustic resonator, wherein each electroacoustic resonator is a series resonator and at least one electroacoustic resonator is tunable;
- and
- a plurality of impedance converters, each impedance converter connected in series between two basic elements, wherein the impedance converters are impedance inverters, wherein the at least one tunable resonator comprises a resonator element and a tunable impedance element that is interconnected in series or in parallel with the resonator element,
- wherein at least one of the plurality of impedance converters comprises three parallel capacitive elements.
1 more element
A Radio Frequency (RF) filter, comprising
- a plurality of basic elements connected in series, each having an electroacoustic resonator, wherein each electroacoustic resonator is a series resonator and at least one electroacoustic resonator is tunable;
- and
- a plurality of impedance converters, each impedance converter connected in series between two basic elements, wherein the impedance converters are impedance inverters, wherein the at least one tunable resonator comprises a resonator element and a tunable impedance element that is interconnected in series or in parallel with the resonator element,
- wherein at least one of the plurality of impedance converters comprises three parallel inductive elements.
1 more element
Dependencies are inferred from the claim text.