CAPACITANCE ELEMENT AND RESONANCE CIRCUIT

• US 20110037536A1
• Filed: 07/28/2010
• Published: 02/17/2011
• Est. Priority Date: 08/11/2009
• Status: Active Grant

• Current Assignee: Sony Chemical & Information Device Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Sato, Noritaka, Kanno, Masayoshi
• Granted Patent: US 8,884,720 B2
• Time in Patent Office: Days
• US Class Current: 333/185
• CPC Class Codes: H01G 4/005 Electrodes

Abstract

A capacitance element includes a first electrode, a second electrode, a third electrode, a fourth electrode, a first dielectric portion, a second dielectric portion, and a third dielectric portion. To the first electrode, a signal having a first polarity is applied. To the second electrode, a signal having a second polarity is applied. The second polarity is opposite to the first polarity. To the third electrode, the signal having the second polarity is applied. The third electrode is disposed on a position opposed to the second electrode. To the fourth electrode, the signal having the first polarity is applied. The first dielectric portion is provided between the first electrode and the second electrode. The second dielectric portion is provided between the second electrode and the third electrode. The third dielectric portion is provided between the third electrode and the fourth electrode.

Claims

1. A capacitance element comprising:

a first electrode to which a signal having a first polarity is applied;

a second electrode to which a signal having a second polarity is applied, the second polarity being opposite to the first polarity;

a third electrode to which the signal having the second polarity is applied, the third electrode being disposed on a position opposed to the second electrode;

a fourth electrode to which the signal having the first polarity is applied;

a first dielectric portion provided between the first electrode and the second electrode;

a second dielectric portion provided between the second electrode and the third electrode; and

a third dielectric portion provided between the third electrode and the fourth electrode.

2. The capacitance element according to claim 1,

wherein the first dielectric portion is formed of a first dielectric layer, the first electrode is formed on a first surface of the first dielectric layer, and the second electrode is formed on a second surface of the first dielectric layer, the second surface being opposite to the first surface,

wherein, when the first electrode is projected on the second surface on which the second electrode is formed, a projection pattern of the first electrode is overlapped with the second electrode,

wherein the third dielectric portion is formed of a third dielectric layer, the third electrode is formed on a first surface of the third dielectric layer, and the fourth electrode is formed on a second surface of the third dielectric layer, the second surface being opposite to the first surface, and

wherein, when the third electrode is projected on the second surface on which the fourth electrode is formed, a projection pattern of the third electrode is overlapped with the fourth electrode.

3. The capacitance element according to claim 2,

wherein the first electrode includes a first electrode portion that is extended in a first direction on the first surface of the first dielectric layer,

wherein the second electrode includes a second electrode portion that is extended in a second direction on the second surface of the first dielectric layer, the second direction and the first direction being intercrossed,

wherein the third electrode includes a third electrode portion that is extended in the second direction on the first surface of the third dielectric layer, and

wherein the fourth electrode includes a fourth electrode portion that is extended in the first direction on the second surface of the third dielectric layer.

4. The capacitance element according to claim 1,

wherein the first dielectric portion is formed of a first dielectric layer, the first electrode is formed on a first surface of the first dielectric layer, and the second electrode is formed on a second surface of the first dielectric layer, the second surface being opposite to the first surface,

wherein, when the first electrode is projected on the second surface on which the second electrode is formed, a projection pattern of the first electrode is not overlapped with the second electrode,

wherein the third dielectric portion is formed of a third dielectric layer, the third electrode is formed on a first surface of the third dielectric layer, and the fourth electrode is formed on a second surface of the third dielectric layer, the second surface being opposite to the first surface, and

wherein, when the third electrode is projected on the second surface on which the fourth electrode is formed, a projection pattern of the third electrode is not overlapped with the fourth electrode.

5. The capacitance element according to claim 1,

wherein the second dielectric portion includes at least two dielectric layers and a fifth electrode to which the signal having the second polarity is applied, the fifth electrode being formed between the two dielectric layers.

6. The capacitance element according to claim 1,

wherein the first electrode and the second electrode are formed on the same surface while being separated at a predetermined interval, and the first dielectric portion is a part of the second dielectric portion disposed between the first electrode and the second electrode, and

wherein the third electrode and the fourth electrode are formed on the same surface while being separated at a predetermined interval, and the third dielectric portion is a part of the second dielectric portion disposed between the third electrode and the fourth electrode.

7. The capacitance element according to claim 1,

wherein the first dielectric portion and the third dielectric portion are each made of a ferroelectric material, and have a capacitance that is changed in accordance with a control signal externally applied.

8. A resonance circuit comprising:

a resonance capacitor including a capacitance element, the capacitance element including

a first electrode to which a signal having a first polarity is applied,

a second electrode to which a signal having a second polarity opposite to the first polarity is applied,

a third electrode which is disposed on a position opposed to the second electrode and to which the signal having the second polarity is applied,

a fourth electrode to which the signal having the first polarity is applied,

a first dielectric portion provided between the first electrode and the second electrode,

a second dielectric portion provided between the second electrode and the third electrode, and

a third dielectric portion provided between the third electrode and the fourth electrode; and

a resonance coil connected to the resonance capacitor.