Multilayered ferroelectric composite waveguides

• US 5,830,591 A
• Filed: 04/29/1996
• Issued: 11/03/1998
• Est. Priority Date: 04/29/1996
• Status: Expired due to Term

• Current Assignee: United States Of America As Represented By The Secretary Of The Army (Government of the United States of America)
• Original Assignee: United States Of America As Represented By The Secretary Of The Army (Government of the United States of America)
• Inventors: Sengupta, Louise, Klushens, Michael S.
• Primary Examiner(s): Speer, Timothy M.
• Application Number:
  US08/639,152
• Time in Patent Office: 918 Days
• Field of Search: 428/699, 428/701, 428/702, 428/1 A, 385/130, 385/131
• US Class Current: 428/701
• CPC Class Codes: B32B 18/00 Layered products essentially comprising ceramics, e.g. refractory products
• CPC Class Codes: C04B 2237/34 Oxidic
• CPC Class Codes: C04B 2237/343 Alumina or aluminates
• CPC Class Codes: C04B 2237/346 Titania or titanates
• CPC Class Codes: C04B 2237/348 Zirconia, hafnia, zirconates or hafnates
• CPC Class Codes: C04B 2237/68 Forming laminates or joining articles wherein at least one substrate contains at least two different parts of macro-size, e.g. one ceramic substrate layer containing an embedded conductor or electrode
• CPC Class Codes: C04B 2237/704 of one or more of the ceramic layers or articles
• CPC Class Codes: C04B 35/4682 based on BaTiO3 perovskite phase
• CPC Class Codes: C04B 35/645 Pressure sintering
• CPC Class Codes: C04B 37/001 directly with other burned ceramic articles
• CPC Class Codes: H01P 1/181 using ferroelectric devices
• CPC Class Codes: Y10T 428/24174 including sheet or component perpendicular to plane of web or sheet

Abstract

A multi-layer Ferroelectric composite wave guide in which the effective dielectric constant of the waveguide can be reduced while maintaining tunability. The waveguide is constructed of high and low dielectric constant layers. The multi-layer waveguide is comprised of bias plates which are perpendicular to the laminate direction on direction of film deposition to maintain tunability in the structure.

Claims

1. A multi-layer ferroelectric composite wave-guide comprising:

a biased, tape cast laminated layers of Barium-Strontium-Titanate represented by the formula Ba_1-x Sr_x TiO₃, wherein x is greater than 0.0, but less than or equal to 0.75, and

a binary compound selected from the group consisting of ZrO₂, Al₂ O₃, MgO, MgZrO₃, MgZrTiO₃, MgAl₂ O₄, and MgTiO₃, in an amount sufficient to provide a composite having a dielectric constant in the range of approximately 5 to 200, a low loss tangent of approximately 0.001, and tunability of approximately 10.41% to about 15.03% at an electric field of 2 V/micron.

2. The multi-layer ferroelectric composite wave-guide of claim 1, comprising biased plates positioned perpendicular to the laminate direction.

3. The multi-layer ferroelectric composite wave-guide of claim 1, wherein the weight ratio of said Barium-Strontium-Titanate to the binary compound is in the range of from approximately 99%-40% Barium-Strontium-Titanate to approximately 1%-40% binary compound.

4. The multi-layer ferroelectric composite wave-guide of claim 1, wherein the weight of said Barium-Strontium-Titanate to said binary compound is in the ranges of approximately 70% Barium-Strontium-Titanate to 30% binary compound.

5. The multi-layer ferroelectric composite wave-guide of claim 1 comprising alternating layers of high dielectric constant and low dielectric constant materials sufficient to produce a tunability of >

5% with 2.0 V/micron.

6. The multi-layer ferroelectric composite wave-guide of claim 5 wherein the alternating layers of the high dielectric constant material are 400 <

ε

_r <

1500, and the alternating layer of the low dielectric constant material are 11<

ε

_r <

100.

7. The multi-layer ferroelectric composite wave-guide of claim 6, wherein the alternating layer of the high dielectric constant is a screen printed layer of high constant material deposited onto a alternating layer of a low dielectric constant substrate.

8. The multi-layer ferroelectric composite wave-guide of claim 7, further comprising bias means wherein the bias means is a plate positioned perpendicular to the printed screen and to the alternating layer of a low dielectric constant substrate.