Dexerials Corporation

Sony Corporation

Toshiaki Yokota

Masayoshi Kanno

Makoto Watanabe

Kazutaka Habu

Noritaka Sato

Katsuhisa Orihara

Satoru Sugita

Yoshimi Takahashi

To suppress changes in capacitance due to displacement between electrodes opposing each other across a dielectric layer, thereby allowing stable manufacturing of a capacitance device having a desired capacitance. A capacitance device is of a configuration including a dielectric layer, a first electrode formed on a predetermined surface of the dielectric layer, and a second electrode formed on a surface on the opposite side of the dielectric layer from the predetermined surface. The forms of the first and second electrodes are set so that even in the event that the first electrode is relatively displaced regarding position in a predetermined direction as to the second electrode, the area of the opposing-electrode region between the first electrode and to the second electrode is unchanged.

Capacitance device and resonance circuit

An antenna device, capable of stable communications without increasing a space of the entire device by keeping a resonance frequency substantially constant even if the temperature changes, includes: an antenna circuit having an antenna coil with an electrically connected capacitor; the coil receiving a magnetic field transmitted from a reader/writer at a predetermined oscillation frequency; the circuit becoming communicable when inductively coupled to the reader/writer; and a magnetic sheet formed at a position superposed on the coil to change its inductance, wherein the coil has a temperature characteristic in which the inductance is changed with a temperature change, and the sheet has a temperature characteristic of changing the inductance to achieve a characteristic inverse to the inductance change with the temperature change in a predetermined use temperature range, and substantially matching a resonance frequency of the circuit with the oscillation frequency in the use temperature region.

Antenna device and communication device

A contactless receiver is provided with a receiving section and a rectification section. The receiving section has a resonant circuit including a resonant capacitor having a variable capacitance element formed with a ferroelectric material, a capacitance of the variable capacitance element changing according to a received voltage at a predetermined frequency, and a resonance coil connected to the resonant capacitor. The rectification section converts an alternating current voltage output from the receiving section into a direct current voltage.

Contactless receiver, resonant circuit, and variable capacitance element

To suppress changes in capacitance due to displacement between electrodes opposing each other across a dielectric layer, thereby allowing stable manufacturing of a capacitance device having a desired capacitance. The capacitance device according to the present invention is of a configuration including a dielectric layer (), a first electrode () formed on a predetermined surface () of the dielectric layer (), and a second electrode () formed on a surface () on the opposite side of the dielectric layer () from the predetermined surface (). The forms of the first and second electrodes () are set so that even in the event that the first electrode () is relatively displaced regarding position in a predetermined direction as to the second electrode (), the area of the opposing-electrode region between the first electrode () and to the second electrode () is unchanged.

A variable capacitor and a control method thereof capable of responding to applications of electronic apparatuses including various electronic devices and communication mobile devices. The variable capacitor includes a pair of electrodes formed so as to sandwich a ferroelectric material layer, in which polarization processing higher than a coercive field in hysteresis characteristics of polarization has been performed to the ferroelectric material layer, and the capacitance can be varied in accordance with a control voltage applied to the electrodes.

Variable capacitor, control method thereof, electronic device and communication mobile device

Disclosed is a variable capacitor that includes signal electrodes configured to sandwich a dielectric layer so as to generate a signal electric field, and control electrodes configured to sandwich the dielectric layer so as to generate a control electric field in a direction intersecting with the signal electric field generated between the signal electrodes.

Growing community of inventors

Miyagi, Japan

Toshiaki Yokota