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US 2015/0109072 A1Published application
System and Method for a Tunable Capacitance Circuit
AssigneeInfineon Technologies AG
InventorWinfried Bakalski
Life of this patent
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Abstract
A tunable capacitance circuit comprises a plurality of varactor transistors which are coupled in series. An antenna tuner comprises such a tunable capacitance circuit.
Claims37
A tunable capacitance circuit, comprising:
- a plurality of varactor transistors coupled in series.
A method for providing a tunable capacitance, the method comprising:
- providing a first capacitance using a plurality of varactor transistors which are coupled in series, wherein the varactor transistors are operated at a first bias condition;
- and
- providing a second capacitance using the plurality of varactor transistors, wherein the varactor transistors are operated at a second bias condition.
A tunable capacitance circuit, comprising:
- a plurality of varactor transistors, which are coupled in series, wherein
- the varactor transistors are formed in or on a substrate, and wherein the substrate is biased such that drain-bulk diodes and source-bulk diodes of the varactor transistors are reverse-biased,
- a source terminal of a first field-effect transistor of the plurality of varactor transistors is coupled with a drain terminal of the first field-effect transistor,
- a source terminal of a second field-effect transistor of the plurality of varactor transistors is coupled with a drain terminal of the second field-effect transistor, and
- a gate terminal of the first field-effect transistor is coupled with a gate terminal of the second field-effect transistor, such that the first field-effect transistor acts as a first varactor transistor, and such that the second field-effect transistor acts as a second varactor transistor,
- a capacitance of the first field-effect transistor depends on a gate-source bias voltage applied to the first field-effect transistor, and
- a capacitance of the second field-effect transistor depends on a gate-source bias voltage applied to the second field-effect transistor;
- wherein a source terminal and a drain terminal of the second field-effect transistor are coupled to a reference potential via an impedance element,
- a gate terminal of the first field-effect transistor and a gate terminal of the second field-effect transistor are coupled to a control voltage provider via a gate impedance element, and
- the control voltage provider is configured to switch a control voltage, which is applied to the gate terminals of the field-effect transistors, between two discrete values.
7 more elements
A tunable capacitance circuit comprising:
- a plurality of varactor elements coupled in series, wherein each varactor element comprises a first transistor comprising
- a control node coupled to a first terminal of the varactor element and to a tuning node, and
- a plurality of output nodes coupled to a second terminal of the varactor element.
A circuit comprising:
- a plurality of tunable capacitance branches coupled to a respective plurality of branch tuning nodes, wherein each tunable capacitance branch comprises a plurality of varactor elements coupled in series, each varactor element comprising a first transistor having a control node coupled to a first terminal of the varactor element and to the respective branch tuning node, and a plurality of output nodes coupled to a second terminal of the varactor element.
Dependencies are inferred from the claim text.