Voltage tuning of microwave magnetic devices using magnetoelectric transducers

• US 9,142,870 B2
• Filed: 01/18/2011
• Issued: 09/22/2015
• Est. Priority Date: 01/21/2010
• Status: Expired due to Fees

• Current Assignee: Northeastern University
• Original Assignee: Northeastern University
• Inventors: Harris, Vincent, Geiler, Anton, Vittoria, Carmine
• Primary Examiner(s): Lee, Benny
• Assistant Examiner(s): SALAZAR JR, JORGE L
• Application Number:
  US13/574,780
• Publication Number:
  US 20120293023A1
• Time in Patent Office: 1,708 Days
• Field of Search: 333/24.1, 333/158, 333/161, 333/204, 333/238, 333/205
• US Class Current: 1/1
• CPC Class Codes: H01P 1/184 Strip line phase-shifters H01P1/181, H01P1/185, H01P1/19 take precedence
• CPC Class Codes: H01P 1/19 using a ferromagnetic device
• CPC Class Codes: H10N 35/00 Magnetostrictive devices integrated devices or assemblies of multiple devices H10N39/00

Abstract

Tunable microwave magnetic devices that provide increased performance with reduced size, weight, and cost. The disclosed microwave magnetic devices are voltage-tunable devices that include ferrite substrates. To tune the devices, the magnetic permeability of the respective ferrite substrates is varied by external, voltage-tuned, magnetic fringe fields created by one or more magnetoelectric (ME) transducers.

Claims

1. A tunable microwave magnetic device, comprising:

a ferrite substrate;

a micro-strip circuit formed on the ferrite substrate; and

at least one magnetoelectric (ME) transducer, wherein the at least one ME transducer includes one or more piezoelectric layers and one or more magnetostrictive layers,

wherein the at least one ME transducer is operative, in response to a voltage applied across the at least one ME transducer, to create an external magnetic fringe field emanating from the at least one ME transducer, the external magnetic fringe field effectively penetrating the ferrite substrate for tuning the microwave magnetic device.

2. The device of claim 1, each of the one or more magnetostrictive layers being bonded to at least one of the one or more piezoelectric layers.

3. The device of claim 2 wherein at least one of the one or more magnetostrictive layers is disposed in a plane of the ferrite substrate.

4. The device of claim 2 wherein at least one of the one or more magnetostrictive layers is disposed in contact with the ferrite substrate.

5. The device of claim 2 wherein the one or more magnetostrictive layers are implemented using Terfenol-D.

6. The device of claim 2 wherein the one or more piezoelectric layers are implemented using lead magnesium niobate-lead titanate (PMN-PT) single crystal.

7. The device of claim 2 wherein the voltage applied across the at least one ME transducer also creates an electric field in the at least one ME transducer, the electric field producing, via an ME effect, a mechanical strain in the one or more piezoelectric layers, and wherein each of the one or more piezoelectric layers is operative, in response to the mechanical strain, to transmit a force in at least one of the one or more magnetostrictive layers, thereby inducing an effective internal magnetic field within the at least one of the one or more magnetostrictive layers.

8. The device of claim 7 wherein the effective internal magnetic field within the at least one of the one or more magnetostrictive layers varies a magnetization state of the at least one of the one or more magnetostrictive layers, and wherein the at least one of the one or more magnetostrictive layers is operative, in response to the varied magnetization state, to create the external magnetic fringe field emanating from the at least one ME transducer.

9. The device of claim 1 wherein the at least one ME transducer includes two piezoelectric layers of the one or more piezoelectric layers, and a single magnetostrictive layer of the one or more magnetostrictive layers between the two piezoelectric layers.

10. The device claim 9 wherein the single magnetostrictive layer is disposed in contact with the ferrite substrate.

11. The device of claim 9 wherein the single magnetostrictive layer is mechanically coupled to each of the two piezoelectric layers.

12. The device of claim 9 wherein the single magnetostrictive layer is disposed in a plane of the ferrite substrate.

13. The device of claim 1 wherein the at least one ME transducer operates with a high remnant magnetization, obviating a need for external biasing components.

14. The device of claim 1 wherein the micro-strip circuit formed on the ferrite substrate is a meander line micro-strip circuit.

15. The device of claim 14 wherein the meander line micro-strip circuit is a meander line micro-strip ferrite phase shifter.

16. A method of tuning a microwave magnetic device, comprising the steps of:

disposing the microwave magnetic device proximate to at least one magnetoelectric (ME) transducer, wherein the at least one ME transducer includes one or more piezoelectric layers and one or more magnetostrictive layers; and

applying a voltage across the at least one ME transducer to create an external magnetic fringe field emanating from the at least one ME transducer, the external magnetic fringe field effectively penetrating the microwave magnetic device for tuning the microwave magnetic device.

17. The method of claim 16 wherein the microwave magnetic device includes a ferrite substrate, each of the one or more magnetostrictive layers being bonded to at least one of the one or more piezoelectric layers, and wherein the disposing of the microwave magnetic device includes disposing the microwave magnetic device proximate to the at least one ME transducer such that at least one of the one or more magnetostrictive layers of the at least one ME transducer is in a plane of the ferrite substrate.

18. The method of claim 16 wherein the microwave magnetic device includes a ferrite substrate, each of the one or more magnetostrictive layers being bonded to at least one of the one or more piezoelectric layers, and wherein the disposing of the microwave magnetic device further includes disposing the microwave magnetic device proximate to the at least one ME transducer such that at least one of the one or more magnetostrictive layers of the at least one ME transducer is in contact with the ferrite substrate.

19. A tunable microwave magnetic device, comprising:

a substrate having a magnetic permeability;

a circuit formed on the substrate; and

at least one magnetoelectric (ME) transducer, wherein the at least one ME transducer includes one or more piezoelectric layers and one or more magnetostrictive layers,

wherein the at least one ME transducer is operative, in response to a voltage applied across the at least one ME transducer, to create an external magnetic fringe field emanating from the at least one ME transducer, the external magnetic fringe field varying the magnetic permeability of the substrate for tuning the microwave magnetic device.

20. The device of claim 19 wherein the substrate is a ferrite substrate.