Taiyo Yuden Co., Ltd.

Tomokazu Ikenaga

Daiki Ishii

Kentaro Morito

Masashi Natsume

Kentaro Nakamura

A variable capacitor includes: capacitors connected in series between first and second signal terminals, capacitances of the capacitors varying in accordance with variable voltage applied to a variable terminal; a first resistor connected between a first node between adjacent capacitors of the capacitors and the variable terminal, a second resistor connected between a second node between adjacent capacitors of the capacitors and a fixed terminal applied with fixed voltage, and a third resistor connected between a third node and the fixed terminal, the third node being located between the first and/or second signal terminal and a capacitor located closest to the first and/or signal terminal among the capacitors, wherein a resistance of the second resistor is less than 1 and &#xbd; or greater with respect to a resistance of the third resistor, and the resistance of the second resistor is not equal to a resistance of the first resistor.

Variable capacitor and electronic device

A variable capacitance device includes: (A) a first signal line that contains multiple first variable capacitance elements connected in series; (B) a second signal line that contains multiple second variable capacitance elements connected in series; (C) a first bias line used for applying a first direct-current voltage to each of the multiple first variable capacitance elements and multiple second variable capacitance elements; and (D) a second bias line used for applying a second direct-current voltage to each of the multiple first variable capacitance elements and multiple second variable capacitance elements. And, a part of at least one of the first bias line and second bias line is arranged so that it passes between two adjacent first variable capacitance elements among the multiple first variable capacitance elements.

Variable capacitance device and communication apparatus

The variable capacitance device includes one or more of directional elements inserted between the third and fourth terminals that allow current to pass only in prescribed directions, such that a diagram formed of current paths from the third terminal to the fourth terminal for the plurality of third-terminal side resistors and the plurality of fourth-terminal side resistors when the third terminal is biased higher than the fourth terminal is line-symmetric to a diagram formed of current paths from the fourth terminal to the third terminal for the plurality of third-terminal side resistors and the plurality of fourth-terminal side resistors when the fourth terminal is biased higher than the third terminal, with respect to the serial chain of variable capacitance elements between the first and second terminals.

Variable capacitance device and antenna device

A variable capacitance capacitor element according to an embodiment of the present invention comprises: a supporting substrate; a first electrode layer provided on the supporting substrate; a second electrode layer provided opposite to the first electrode layer; and a dielectric layer positioned between the first electrode layer and the second electrode layer. In accordance with an aspect, a main component of the dielectric layer is represented by a composition formula BaSrTiO(0.5&#x2266;x&#x2266;0.8), and the first thin film dielectric layer has a thickness of 200 nm or smaller.

Variable capacitance capacitor element

A variable capacitance device includes: a supporting substrate having a plurality of variable capacitance elements formed thereon, the plurality of variable capacitance elements being connected in series, wherein each of the plurality of variable capacitance elements has a separate lower electrode, or at least some of the plurality of variable capacitance elements share a lower electrode, thereby forming a plural set of the lower electrodes that serves as the lower electrodes of the respective variable capacitance elements, wherein the variable capacitance device further includes an insulating moisture-resistant film and a conductive adhesive film, and wherein the conductive adhesive film and the insulating moisture-resistant film have a gap in a plan view between at least some of regions where the plural set of the lower electrodes are respectively formed so as to avoid electrical leakage between said at least some of regions through the conductive adhesive film.

A variable capacitance device includes: a first and second terminal for signals; a plural, even number of variable capacitance elements connected in-series between the first and second terminal; a third and fourth terminal for receiving a same voltage; a fifth and sixth terminal for grounding; a plurality of first resistors connected to either the third or fourth terminal on one end; and a plurality of second resistors connected to either the fifth or sixth terminal on one end. With respect to a series of successive nodes beginning with the first terminal and ending with the second terminal, respective other ends of a pair of the first resistors are connected to every other node, and respective other ends of a pair of the second resistors are connected to the remaining every other node, such that the pairs of first and second resistors are alternately connected to the series of successive nodes.

Variable capacitance device and antenna apparatus

A variable capacity composite component has structures connecting four variable capacitors, for example, to signal terminals in series with bias application terminals of opposite polarities facing each other, connecting a power supply terminal to the bias+ sides of the first and second variable capacitors via a first bias resistance, and also to the bias+ sides of the third and fourth variable capacitors via a second bias resistance, connecting a grounding terminal to the bias&#x2212; side of the first variable capacitor via a third bias resistance, also to the bias&#x2212; sides of the second and third variable capacitors via a fourth bias resistance, and also to the bias&#x2212;sides of the fourth variable capacitor via a fifth bias resistance, and setting the value of the first, second, and fourth bias resistances to one-half the value of the third and fifth bias resistances.

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Tokyo, Japan

Tomokazu Ikenaga