US6160524A
Expired / Lapsed
US
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Apparatus and method for reducing the temperature sensitivity of ferroelectric microwave devices
Assignee: United States Department of the Army
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Filing: 1999-03-17
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Granted: 2000-12-12
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Expires: 2019-03-17
Abstract
Abstract To control the temperature sensitivity of a ferroelectric microwave device, a microwave waveguide in the device is loaded with a modified ferroelecc material of reduced grain size less than 100 nm, preferably about 50 nm. The electrical properties of this material are less sensitive to temperature change. Thus, when a dc bias voltage is applied across the ferroelectric to tune the dielectric constant, changes in temperature will have a minimal effect on the desired tuning of the device.
Inventors
- 👤 William D. Wilber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:10
CPC Classifications
H; H01; H01Q; H01Q1/00; H01Q1/002
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
159 words
A ferroelectric microwave device with reduced temperature sensitivity, comprising: a ferroelectric body is placed between a waveguide structure means and a ground plane; said ferroelectric body, being loaded with a ferroelectric material composed of a plurality of ferroelectric grains, is connected to a high frequency transmission line of said waveguide structure; a dc bias voltage means applies a dc voltage across said ferroelectric material to provide a dc electric field across said ferroelectric material; a propagating electromagnetic energy is generated by dc electric field; said ferroelectric body having a given dielectric constant in the presence of a zero bias electric field secured to said waveguide structure whereby at least a portion of said propagating electromagnetic field is propagated through said ferroelectric body; a means for producing a dc bias field through said ferroelectric body for modifying the dielectric constant thereof in a predetermined manner; and said ferroelectric body having a grain size which is less than about 100 nm.
Claim 2
Dependent Claim
159 words
A ferroelectric microwave device with reduced temperature sensitivity, comprising: a ferroelectric body is placed between a waveguide structure means and a ground plane; said ferroelectric body, being loaded with a ferroelectric material composed of a plurality of ferroelectric grains, is connected to a high frequency transmission line of said waveguide structure; a dc bias voltage means applies a dc voltage across said ferroelectric material to provide a dc electric field across said ferroelectric material; a propagating electromagnetic energy is generated by dc electric field; said ferroelectric body having a given dielectric constant in the presence of a zero bias electric field secured to said waveguide structure whereby at least a portion of said propagating electromagnetic field is propagated through said ferroelectric body; a means for producing a dc bias field through said ferroelectric body for modifying the dielectric constant thereof in a predetermined manner; and said ferroelectric body having a grain size which is less than about 100 nm.
Claim 3
Dependent Claim
16 words
The microwave device of claim 1, in which said wave guide structure is a microstrip waveguide.
Claim 4
Dependent Claim
20 words
The microwave device of claim 2, in which said ferroelectric body has a grain size which is about 50 nm.
Claim 5
Dependent Claim
15 words
The microwave device of claim 1, in which said ferroelectric body is barium strontium titanate.
Claim 6
Dependent Claim
20 words
The microwave device of claim 4, in which said ferroelectric body has a grain size which is about 50 nm.
Claim 7
Dependent Claim
20 words
The microwave device of claim 1, in which said ferroelectric body has a grain size which is about 50 nm.
Claim 8
Dependent Claim
19 words
The microwave device of claim 1, in which said ferroelectric body is heated to slightly above its Curie temperature.
Claim 9
Dependent Claim
20 words
The microwave device of claim 7, in which said ferroelectric body has a grain size which is about 50 nm.
Claim 10
Independent Claim
200 words
A method of reducing sensitivity of a ferroelectric microwave device, the steps of: loading a ferroelectric body with a ferroelectric material composed of a plurality of ferroelectric grains, each of said plurality of grains having a grain size of less than 100 nm; forming said ferroelectric body to a given shape; placing said ferroelectric body between a waveguide structure means and a ground plane; connecting said ferroelectric material to a high frequency transmission line of said waveguide structure; securing said ferroelectric body to an interior surface of said high frequency transmission line which guides the transmission therethrough of a propagating electromagnetic energy; said ferroelectric body providing a given dielectric constant in the presence of a zero bias electric field secured to said waveguide structure whereby at least a portion of said propagating electromagnetic field is propagated through said ferroelectric body; applying an electric field bias means to said ferroelectric body in such a way that the variation of an electric field from said bias means will vary the dielectric constant of said ferroelectric body in a predetermined manner, whereby an energy propagating field through said transmission line is controlled in a predetermined manner and is relatively insensitive to temperature variations.
Claim 11
Independent Claim
200 words
A method of reducing sensitivity of a ferroelectric microwave device, the steps of: loading a ferroelectric body with a ferroelectric material composed of a plurality of ferroelectric grains, each of said plurality of grains having a grain size of less than 100 nm; forming said ferroelectric body to a given shape; placing said ferroelectric body between a waveguide structure means and a ground plane; connecting said ferroelectric material to a high frequency transmission line of said waveguide structure; securing said ferroelectric body to an interior surface of said high frequency transmission line which guides the transmission therethrough of a propagating electromagnetic energy; said ferroelectric body providing a given dielectric constant in the presence of a zero bias electric field secured to said waveguide structure whereby at least a portion of said propagating electromagnetic field is propagated through said ferroelectric body; applying an electric field bias means to said ferroelectric body in such a way that the variation of an electric field from said bias means will vary the dielectric constant of said ferroelectric body in a predetermined manner, whereby an energy propagating field through said transmission line is controlled in a predetermined manner and is relatively insensitive to temperature variations.
Claim 12
Dependent Claim
21 words
The method of manufacture of a microwave device of claim 9, in which said wave guide structure is a microstrip waveguide.
Claim 13
Dependent Claim
25 words
The method of manufacture of a microwave device of claim 9, in which said ferroelectric body has a grain size which is about 50 nm.
Claim 14
Dependent Claim
27 words
The method of manufacture of a microwave device of claim 9, in which said ferroelectric body is adapted to be heated to slightly above its Curie temperature.
References Cited (Backward Citations)
US5557286A
Cited
US5731220A
Cited
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