US6100773A
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Impedance matching device
Assignee: Sharp Corp
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Filing: 1998-09-18
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Granted: 2000-08-08
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Expires: 2018-09-18
Abstract
Abstract An impedance matching device includes a variable capacitor constituted by a non-linear dielectric thin film and an upper electrode disposed on a lower electrode formed on a substrate. The non-linear dielectric thin film is formed by a deposition, screen-printing, electroplating, or other technique, and changes its relative dielectric constant according to applied voltage. Therefore, the capacity of the variable capacitor is controlled and the impedance is matched, by simply controlling the applied voltage across the non-linear dielectric thin film. Consequently, the arrangement makes it possible to cut down the impedance matching device in size and cost, compared to an arrangement incorporating a capacitor and a coil for adjustment, effects a much simpler matching operation, and facilitates a manufacturing process.
Inventors
- 👤 Masumi Nakamichi
- 👤 Yoshiyuki Masuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:28
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/38
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
115 words
An impedance matching device incorporated in a high frequency circuit board, comprising: a voltage-controlled variable capacitor including a non-linear dielectric thin film having a relative dielectric constant in accordance with a strength of an applied electric field, a first electrode formed on one of the sides of the non-linear dielectric thin film, and a second electrode formed on an opposite side of the non-linear dielectric thin film; and a control voltage application section for applying a control voltage across the first and second electrodes, one of the first and second electrodes receiving a high frequency signal as an input and another of the first and second electrodes providing a high frequency signal as an output.
Claim 2
Dependent Claim
115 words
An impedance matching device incorporated in a high frequency circuit board, comprising: a voltage-controlled variable capacitor including a non-linear dielectric thin film having a relative dielectric constant in accordance with a strength of an applied electric field, a first electrode formed on one of the sides of the non-linear dielectric thin film, and a second electrode formed on an opposite side of the non-linear dielectric thin film; and a control voltage application section for applying a control voltage across the first and second electrodes, one of the first and second electrodes receiving a high frequency signal as an input and another of the first and second electrodes providing a high frequency signal as an output.
Claim 3
Dependent Claim
33 words
The impedance matching device as set forth in claim 1, wherein the non-linear dielectric thin film is made of BaTiO 3 , SrTiO 3 , or Ba x Sr 1-x TiO 3 (0<x<1).
Claim 4
Dependent Claim
29 words
The impedance matching device as set forth in claim 2, wherein the non-linear dielectric thin film has a uniform thickness in a range of 0.05 μm to 10 μm.
Claim 5
Dependent Claim
35 words
The impedance matching device as set forth in claim 1, wherein the non-linear dielectric thin film is formed directly on a high frequency circuit substrate made of a dielectric ceramic substrate or a glass substrate.
Claim 6
Dependent Claim
41 words
The impedance matching device as set forth in claim 4, wherein the non-linear dielectric thin film is formed directly on the high frequency circuit substrate by a deposition technique, a printing technique, or a sol-gel technique using an organic metal salt.
Claim 7
Dependent Claim
23 words
The impedance matching device as set forth in claim 5, wherein the non-linear dielectric thin film is formed by a photo etching technique.
Claim 8
Dependent Claim
19 words
The impedance matching device as set forth in claim 6, wherein the photo etching technique is a lift-off technique.
Claim 9
Dependent Claim
30 words
The impedance matching device as set forth in claim 1, wherein the non-linear dielectric thin film is made of Ba x Sr 1-x TiO 3 (0<x<1) by a sol-gel technique.
Claim 10
Dependent Claim
36 words
The impedance matching device as set forth in claim 5, wherein the non-linear dielectric thin film has an outer circumferential edge covered with an insulating film made of a material having a low relative dielectric constant.
Claim 11
Dependent Claim
25 words
The impedance matching device as set forth in claim 9, wherein the insulating film is made of SiO 2 or Al 2 O 3 .
Claim 12
Dependent Claim
30 words
The impedance matching device as set forth in claim 1, wherein the non-linear dielectric thin film is formed on a high frequency circuit substrate by a ceramic green sheet process.
Claim 13
Dependent Claim
38 words
The impedance matching device as set forth in claim 1, wherein the first and second electrodes each are a thick film conductive body each having a thickness in accordance with a frequency range of the high frequency signal.
Claim 14
Dependent Claim
27 words
The impedance matching device as set forth in claim 12, wherein the first and second electrodes each are made of a laminated layer of Pt and Ta.
Claim 15
Dependent Claim
53 words
The impedance matching device as set forth in claim 1, wherein the voltage-controlled variable capacitor has a capacity that is specified to change with a relative dielectric constant of the non-linear dielectric thin film, so as to compensate for an irregularity in design and manufacture of the capacity of the voltage-controlled variable capacitor.
Claim 16
Dependent Claim
107 words
An impedance matching device, comprising: a voltage-controlled variable capacitor, for receiving an input signal, including a non-linear dielectric thin film having a relative dielectric constant in accordance with a strength of an applied electric field, a first electrode formed on one of the sides of the non-linear dielectric thin film, and a second electrode formed on an opposite side of the non-linear dielectric thin film; and a control voltage application section for applying a control voltage across the first and second electrodes, the non-linear dielectric thin film having an outer circumferential edge covered with an insulating film made of a material having a low relative dielectric constant.
Claim 17
Dependent Claim
107 words
An impedance matching device, comprising: a voltage-controlled variable capacitor, for receiving an input signal, including a non-linear dielectric thin film having a relative dielectric constant in accordance with a strength of an applied electric field, a first electrode formed on one of the sides of the non-linear dielectric thin film, and a second electrode formed on an opposite side of the non-linear dielectric thin film; and a control voltage application section for applying a control voltage across the first and second electrodes, the non-linear dielectric thin film having an outer circumferential edge covered with an insulating film made of a material having a low relative dielectric constant.
Claim 18
Dependent Claim
22 words
The impedance matching device of claim 15, wherein the insulating film is made of SiO 2 or Al 2 O 3 .
Claim 19
Independent Claim
105 words
A method of matching an impedance comprising the steps of: providing a non-linear thin-film dielectric between first and second electrodes, the first and second electrodes being thick films; applying a high frequency input signal to one of the first and second electrodes; applying a control voltage across the first and second electrodes to selectively vary a dielectric constant of the non-linear thin-film dielectric; and providing a high frequency output signal from another of the first and second electrodes, the dielectric constant being selectively varied by the control voltage so that a capacity between the first and second electrodes has a reactance matching a desired impedance.
Claim 20
Independent Claim
105 words
A method of matching an impedance comprising the steps of: providing a non-linear thin-film dielectric between first and second electrodes, the first and second electrodes being thick films; applying a high frequency input signal to one of the first and second electrodes; applying a control voltage across the first and second electrodes to selectively vary a dielectric constant of the non-linear thin-film dielectric; and providing a high frequency output signal from another of the first and second electrodes, the dielectric constant being selectively varied by the control voltage so that a capacity between the first and second electrodes has a reactance matching a desired impedance.
Claim 21
Dependent Claim
33 words
The method of impedance matching of claim 17, further comprising the step of covering an outer circumferential edge of the non-linear thin-film dielectric with an insulating film having a low relative dielectric constant.
Claim 22
Dependent Claim
21 words
The method of impedance matching of claim 18, wherein the insulating film is SiO 2 or Al 2 O 3 .
Claim 23
Dependent Claim
30 words
The method of impedance matching of claim 17, wherein thicknesses of the first and second electrodes are selected in accordance with a frequency range of the high frequency input signal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-08-08 | 2004-02-07 | 2004-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-08-08 | 2008-02-07 | 2008-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-08-08 | 2012-02-07 | 2012-08-08 | $7700.00 | Window Closed / Lapsed |