Broadband, Nonreciprocal Network Element

• US 20080203855A1
• Filed: 06/05/2006
• Published: 08/28/2008
• Est. Priority Date: 06/10/2005
• Status: Abandoned Application

• Current Assignee: Novgorod State University, Virginia Tech Intellectual Properties, Inc. (Virginia Polytechnic Institute and State University)
• Original Assignee: Virginia Tech Intellectual Properties, Inc. (Virginia Polytechnic Institute and State University)
• Inventors: Li, Jie-Fang, Viehland, Dwight D., Bichurin, Mirza I.
• Application Number:
  US11/916,472
• Publication Number:
  US 20080203855A1
• Time in Patent Office: Days
• US Class Current: 310/357
• CPC Class Codes: H01F 10/126 containing rare earth metals H01F10/133 takes precedence
• CPC Class Codes: H01F 10/265 Magnetic multilayers non exchange-coupled H01F10/32 takes precedence
• CPC Class Codes: H03H 2/001 comprising magnetostatic wave network elements
• CPC Class Codes: H03H 9/22 Constructional features of resonators consisting of magnetostrictive material
• CPC Class Codes: H10N 30/00 Piezoelectric or electrostrictive devices integrated devices or assemblies of multiple devices H10N39/00

Abstract

A magneto-electric (ME) gyrator, which is a discrete, passive network element, comprises a laminated composite of piezoelectric and magnetostrictive layers. The ME gyrator approximately meets the following criteria: Vy=−α/,, where V is voltage, /is current, and a is a conversion (or gyration) coefficient between voltage and current and non-reciprocity is manifested as a 180° phase shift between open and short circuit (/,F) conditions, and =* 1 (Ib) where c0 is the speed of light in vacuum, εêis the effective relative dielectric constant, and μĉis the effectβive relative permeability.

Claims

1. A magneto-electric (ME) gyrator which is a discrete, non-reciprocal, passive network element comprising a laminated composite of piezoelectric and magnetostrictive layers which approximately meets the following criteria:

V₁=α

I₂,

V₂=α

I₁  

 

(1a)

where V is voltage, I is current, and α

is a conversion (or gyration) coefficient between voltage and current and non-reciprocity is manifested as a 180°

phase shift between open and short circuit (I,V) conditions, and

$\begin{array}{cc}\frac{\mathrm{\alpha <br><br>}<br><br><br><br>c_0}{\sqrt{{\mathrm{\varepsilon <br><br>}}_{\mathrm{eff}}<br><br>{\mathrm{\mu <br><br>}}_{\mathrm{eff}}}}\approx <br><br>1& \left(1<br><br>b\right)\end{array}$

where c₀ is the speed of light in vacuum, ε

_eff is the effective relative dielectric constant, and μ

_eff is the effective relative permeability.

2. The ME gyrator recited in claim 1, wherein the laminated composite comprises a longitudinally-poled piezoelectric layer sandwiched between two longitudinally-magnetized magnetostrictive layers.

3. The ME gyrator recited in claim 1, wherein the laminated composite comprises a piezoelectric plate having a push-pull polarization laminated between two magnetostrictive plates.

4. The ME gyrator recited in claim 1, wherein the laminated composite comprises a transversely-poled piezoelectric layer sandwiched between two longitudinally-magnetized magnetostrictive layers.

5. The ME gyrator recited in claim 1, wherein the laminated composite comprises a symmetrically-poled piezoelectric layer sandwiched between two longitudinally-magnetized magnetostrictive layers.

6. The ME gyrator recited in claim 1, wherein the piezoelectric layer is a Pb(Zr_1-xTi_1-x)O₃ (PZT) layer having a polycrystalline structure.

7. The ME gyrator recited in claim 1, wherein the piezoelectric layer is a (1-x)Pb(Mg_1/3Nb_2/3)O₃-xPbTiO₃ (PMN-PT) layer having a (001) oriented crystalline structure.

8. The ME gyrator recited in claim 1, wherein the piezoelectric layer is a (1-x)Pb(Mg_1/3Nb_2/3)O₃-xPbTiO₃ (PMN-PT) layer having a (111) oriented crystalline structure.

9. The ME gyrator recited in claim 1, wherein the piezoelectric layer is a (1-x)Pb(Mg_1/3Nb_2/3)O₃-xPbTiO₃ (PMN-PT) layer having a (110) oriented crystalline structure.

10. The ME gyrator recited in claim 1, wherein the magnetostrictive layer is Tb_xDy_1-xFe_y (Terfenol-D).

11. The ME gyrator recited in claim 1, wherein the magnetostrictive layer is Fe_1-xGa_x (Galfenol).

12. The ME gyrator recited in claim 1, wherein the laminate composite comprises a uni-morph structure consisting of one transversely-poled piezoelectric layer epoxied to one longitudinally magnetized magnetostrictive layer.

13. The ME gyrator recited in claim 1, wherein the laminate composite comprises a uni-morph structure of claim which operates in a low frequency bending mode.

14. The ME gyrator recited in claim 1, wherein piezoelectric and magnetostrictive layers are repeatedly stacked together in sequence to create a multi-layer laminate.

15. The ME gyrator recited in claim 1, wherein the piezoelectric layer is in general a perovskite ferroelectric, in ceramic or single crystal form.