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US 6,674,321 B1Granted
Circuit configuration for DC-biased capacitors
AssigneeAgile Materials and Technologies, Inc.
InventorRobert A. York
Life of this patent
Estimating the term…
Abstract
A capacitive element includes two or more voltage-variable capacitors (varactors). The varactors are configured so that they are coupled in series with respect to an applied AC signal and are coupled in parallel with respect to an applied DC bias voltage. The effective capacitance of the overall capacitive element can be tuned by varying the DC bias voltage.
Claims26
A voltage-variable capacitive element comprising:
- a first DC bias node and a second DC bias node for receiving a DC bias voltage;
- a first AC node and a second AC node for receiving an AC signal;
- N parallel-plate varactors, wherein N is at least two and each varactor has a capacitance that varies according to a voltage applied across the varactor, each varactor comprising a top electrode, a bottom electrode and a thin film of ferroelectric material sandwiched between the top electrode and the bottom electrode, wherein the N varactors are coupled in parallel between the DC bias nodes with respect to the DC bias voltage and are coupled in series between the AC nodes with respect to the AC signal;
- and
- a substrate, wherein the DC bias nodes, the AC nodes and the N varactors are integrated on the substrate.
2 more elements
An RF power amplifier comprising a tunable reactive matching network, the tunable reactive matching network comprising:
- N parallel-plate varactors, wherein N is at least two and each varactor has a capacitance that varies according to a voltage applied across the varactor, each varactor comprising a top electrode, a bottom electrode and a thin film of ferroelectric material sandwiched between the top electrode and the bottom electrode;
- a first DC bias node and a second DC bias node for receiving a DC bias voltage, wherein the N varactors are coupled in parallel between the DC bias nodes with respect to the DC bias voltage;
- and
- a first AC node and a second AC node for receiving an AC signal, wherein the N varactors are coupled in series between the AC nodes with respect to the AC signal;
- and
- a substrate, wherein the DC bias nodes, the AC nodes and the N varactors are integrated on the substrate.
3 more elements
An RF tunable filter comprising:
- N parallel-plate varactors, wherein N is at least two and each varactor has a capacitance that varies according to a voltage applied across the varactor, each varactor comprising a top electrode, a bottom electrode and a thin film of ferroelectric material sandwiched between the top electrode and the bottom electrode;
- a first DC bias node and a second DC bias node for receiving a DC bias voltage, wherein the N varactors are coupled in parallel between the DC bias nodes with respect to the DC bias voltage;
- and
- a first AC node and a second AC node for receiving an AC signal, wherein the N varactors are coupled in series between the AC nodes with respect to the AC signal;
- and
- a substrate, wherein the DC bias nodes, the AC nodes and the N varactors are integrated on the substrate.
3 more elements
A voltage-variable capacitive element comprising:
- a first DC bias node and a second DC bias node for receiving a DC bias voltage;
- a first AC node and a second AC node for receiving an AC signal;
- N parallel-plate varactors, wherein N is at least two and each varactor has a capacitance that varies according to a voltage applied across the varactor, each varactor comprising top electrode, a bottom electrode and a thin film of ferroelectric material sandwiched between the top electrode and the bottom electrode;
- AC coupling means for coupling the N varactors in series between the AC nodes with respect to the AC signal;
- and
- DC coupling means for coupling the N varactors in parallel between the DC bias nodes with respect to the DC bias voltage.
3 more elements
Dependencies are inferred from the claim text.