US5993947A
Expired / Lapsed
US
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Low temperature coefficient dielectric material comprising binary calcium niobate and calcium tantalate oxides
Assignee: Nokia of America Corp
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Filing: 1997-11-17
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Granted: 1999-11-30
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Expires: 2017-11-17
Abstract
Abstract Dielectric materials comprising Ca2Ta2-xNbxO7 have high dielectric constants (Ks) and relatively low temperature coefficients of dielectric constants (TCKs). Preferably, in this composition 0.20</=x</=1.20 and more preferably 0.32</=x</=0.40, and particularly preferred is the composite where x is 0.36. With a preferred embodiment where x is about 0.36, the dielectric constant is near 30 and the TCK is about 2 ppm/ DEG C., and the Q of the polycrystalline ceramic at 1 MHz is approximately 5000. The dielectric materials are particularly useful in microwave communications applications
Inventors
- 👤 Robert Joseph Cava
- 👤 James Joseph Krajewski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:35
CPC Classifications
H; H01; H01P; H01P7/00; H01P7/10; C; C04; C04B; C04B35/00; C04B35/01; C04B35/495; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24926
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
35 words
A material comprising a composite of Ca 2 Ta 2 O 7 and Ca 2 Nb 2 O 7 for use as a dielectric material having a dielectric constant and temperature coefficient of dielectric constant.
Claim 2
Dependent Claim
35 words
A material comprising a composite of Ca 2 Ta 2 O 7 and Ca 2 Nb 2 O 7 for use as a dielectric material having a dielectric constant and temperature coefficient of dielectric constant.
Claim 3
Dependent Claim
46 words
The dielectric material of claim 1, wherein when measured in bulk polycrystalline form at 20° C. and 1 MHz the dielectric constant of said material is about at least 25 and the temperature coefficient of dielectric constant of said material is less than about 20 ppm/°C.
Claim 4
Dependent Claim
18 words
A dielectric resonator for use in a microwave telecommunication system comprising the dielectric material according to claim 1.
Claim 5
Dependent Claim
35 words
A dielectric resonator according to claim 3 comprising a substrate having surfaces fabricated with the composite according to claim 1 and a plurality of conductors forming a conductor pattern on the surfaces of the substrate.
Claim 6
Dependent Claim
22 words
A dielectric resonator according to claim 3 comprising a block of dielectric material according to claim 1 coated with a metal electrode.
Claim 7
Dependent Claim
19 words
A dielectric filter for use in a microwave telecommunication system comprising a plurality of resonators according to claim 3.
Claim 8
Dependent Claim
46 words
A composite having a dielectric constant and temperature coefficient of dielectric constant for use as a dielectric material prepared by mixing powders of CaCO 3 , Nb 2 O 5 and Ta 2 O 5 and firing the mixture at temperatures of above 1350 degrees Centigrade.
Claim 9
Dependent Claim
46 words
A composite having a dielectric constant and temperature coefficient of dielectric constant for use as a dielectric material prepared by mixing powders of CaCO 3 , Nb 2 O 5 and Ta 2 O 5 and firing the mixture at temperatures of above 1350 degrees Centigrade.
Claim 10
Dependent Claim
40 words
A material comprising Ca 2 Ta 2-x Nb x O 7 , in which x is in the range of about 0.20 to 1.20, for use as a dielectric material having a dielectric constant and temperature coefficient of dielectric constant.
Claim 11
Dependent Claim
40 words
A material comprising Ca 2 Ta 2-x Nb x O 7 , in which x is in the range of about 0.20 to 1.20, for use as a dielectric material having a dielectric constant and temperature coefficient of dielectric constant.
Claim 12
Dependent Claim
9 words
The dielectric material of claim 8, in which 0.32≦x≦0.40.
Claim 13
Dependent Claim
12 words
The dielectric material of claim 9, in which x is about 0.36.
Claim 14
Dependent Claim
47 words
The dielectric material of claim 10, in which when measured in bulk polycrystalline form at 20° C. and 1 MHz the dielectric constant of said material is about at least 25 and the temperature coefficient of dielectric constant of said material is less than about 20 ppm/°C.
Claim 15
Dependent Claim
18 words
A dielectric resonator for use in a microwave telecommunication system comprising a dielectric material according to claim 11.
Claim 16
Dependent Claim
19 words
A dielectric filter for use in a microwave telecommunication system comprising a plurality of resonators according to claim 12.
Claim 17
Independent Claim
142 words
A method of fabricating a dielectric substrate comprising Ca 2 Ta 2 O 7 and Ca 2 Nb 2 O 7 for use in a dielectric resonator or dielectric filter for microwave application, the method comprising the steps of: mixing a first powder of CaCO 3 , a second powder of Nb 2 O 5 and a third powder of Ta 2 O 5 to provide a powder mixture; mechanically grinding the mixture; firing the mixture for more than 15 hours at temperatures above 1350 degrees Centigrade; and pressing the mixture into a disk for use as the dielectric substrate; and firing the disk for a period of 2 to 3 hours at a temperature of about 1425 to 1550 degrees Centigrade to provide the dielectric substrate comprising Ca 2 Ta 2 O 7 and Ca 2 Nb 2 O 7 .
Claim 18
Independent Claim
142 words
A method of fabricating a dielectric substrate comprising Ca 2 Ta 2 O 7 and Ca 2 Nb 2 O 7 for use in a dielectric resonator or dielectric filter for microwave application, the method comprising the steps of: mixing a first powder of CaCO 3 , a second powder of Nb 2 O 5 and a third powder of Ta 2 O 5 to provide a powder mixture; mechanically grinding the mixture; firing the mixture for more than 15 hours at temperatures above 1350 degrees Centigrade; and pressing the mixture into a disk for use as the dielectric substrate; and firing the disk for a period of 2 to 3 hours at a temperature of about 1425 to 1550 degrees Centigrade to provide the dielectric substrate comprising Ca 2 Ta 2 O 7 and Ca 2 Nb 2 O 7 .
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| 3.5 Years (Year 4) | 2002-11-29 | 2003-05-31 | 2003-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-11-29 | 2007-05-31 | 2007-11-30 | $3760.00 | Window Closed / Lapsed |
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