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US 9,484,880 B2Granted
Variable capacitor, impedance matching device, mobile terminal thereof and method for matching impedance
AssigneeLG Innotek Co., Ltd.
InventorChang Wook Kim
Life of this patent
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Abstract
Disclosed is an impedance matching device. Variable devices of the impedance matching device installed in a mobile terminal, such as a portable terminal, are configured to have a MEMS structure. The MEMS structure and other components are integrated as one package, so the manufacturing cost is reduced and the manufacturing efficiency is improved.
Claims10
An impedance matching device comprising:
- a substrate;
- a variable device unit mounted on the substrate and including at least one MEMS variable capacitor to change a capacitance value according to applied voltage;
- a fixed device unit mounted on the substrate and including at least one inductor coupled with the MEMS variable capacitor to form a predetermined time constant;
- a reflective power measurement unit mounted on the substrate to measure an intensity of a reflective wave of a signal transmitted from the variable device unit and the fixed device unit;
- and
- a converting unit mounted on the substrate to output a direct current voltage value by converting the intensity of the reflective wave of the signal measured by the reflective power measurement unit into the direct current voltage value;
- wherein the MEMS variable capacitor comprises:
- a first electrode;
- a second electrode floating above the first electrode;
- a fixed electrode spaced apart from a lateral side of the second electrode;
- and
- a movable electrode interposed between the second electrode and the fixed electrode and connected to the second electrode to physically make contact with the fixed electrode as voltage is applied to the fixed electrode;
- and
- wherein a first insulating layer is formed on the first electrode to inhibit an electrical short between the first electrode and the second electrode, and a second insulating layer is formed on the fixed electrode to inhibit an electrical short between the fixed electrode and the movable electrode.
11 more elements
An impedance matching device comprising:
- a substrate;
- a variable device unit mounted on the substrate and including at least one MEMS variable capacitor to change a capacitance value according to applied voltage;
- a fixed device unit mounted on the substrate and including at least one inductor coupled with the MEMS variable capacitor to form a predetermined time constant;
- a reflective power measurement unit mounted on the substrate to measure an intensity of a reflective wave of a signal transmitted from the variable device unit and the fixed device unit;
- and
- a converting unit mounted on the substrate to output a direct current voltage value by converting the intensity of the reflective wave of the signal measured by the reflective power measurement unit into the direct current voltage value, wherein the MEMS variable capacitor comprises:
- a first electrode;
- a second electrode spaced apart from the first electrode;
- a third electrode floating above the first and second electrodes;
- fourth electrodes connected to the third electrode through a spring structure;
- and
- fifth electrodes formed in opposition to the fourth electrodes and configured to variably adjust a capacitance value of the MEMS variable capacitor;
- wherein when a voltage is applied to the fifth electrodes, a distance between the third electrode and the first and second electrodes is increased in response to the applied voltage, and
- wherein the third electrode is vertically disposed between the fifth electrode and a collection of the first, second, and fourth electrodes.
11 more elements
Dependencies are inferred from the claim text.