MULTIFERROIC ANTENNA/SENSOR

• US 20110062955A1
• Filed: 09/17/2009
• Published: 03/17/2011
• Est. Priority Date: 09/17/2009
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Geren, William P., Hubbell, Stephen P., Miller, Robert J.
• Granted Patent: US 8,760,157 B2
• Time in Patent Office: Days
• US Class Current: 324/249
• CPC Class Codes: G01R 33/18 Measuring magnetostrictive properties
• CPC Class Codes: H01Q 1/32 Adaptation for use in or on road or rail vehicles
• CPC Class Codes: H01Q 1/52 Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure absorbing means H01Q17/00
• CPC Class Codes: H01Q 17/00 Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems

Abstract

A multiferroic antenna and sensor where the sensor includes a multiferroic stack of multiple connected multiferroic layer-pairs, each multiferroic layer-pair comprising an alternating layer of a magnetostrictive material and a piezoelectric material bonded together enabling a high signal sensitivity, a magnetic field of an incident signal causing mechanical strain in the magnetostrictive material layers that strains adjacent piezoelectric material layers producing an electrical voltage in each multiferroic layer-pair proportional to the incident signal. An output of the multiferroic stack comprises the electrical voltage amplified proportional to a total number of multiple connected multiferroic layer-pairs in the multiferroic stack.

Claims

1. A multiferroic sensor comprising:

a multiferroic stack of multiple connected multiferroic layer-pairs, each multiferroic layer-pair comprising an alternating layer of a magnetostrictive material and a piezoelectric material bonded together enabling a high signal sensitivity, a magnetic field of an incident signal causing mechanical strain in the magnetostrictive material layers that strains adjacent piezoelectric material layers producing an electrical voltage in each multiferroic layer-pair proportional to the incident signal,

wherein an output of the multiferroic stack comprises the electrical voltage amplified proportional to a total number of multiple connected multiferroic layer-pairs in the multiferroic stack.

2. The sensor according to claim 1, wherein a length and width of the multiferroic stack are a size allowing the incident signal'"'"'s magnetic field to penetrate an interior of the multiferroic stack from the sides.

3. The sensor according to claim 1, wherein a length and width of the multiferroic stack are a size causing a mechanical resonance that is at least one of higher than an intended operating frequency of the antenna or at the intended operating frequency of the antenna.

4. The sensor according to claim 1, further comprising an array of at least two multiferroic stacks, the at least two multiferroic stacks being connected at least one of in series or in parallel, wherein when the at least two multiferroic stacks are connected in series an amount of voltage delivered by the array is proportional to a number of the at least two multiferroic stacks connected in series, and wherein when the at least two multiferroic stacks are connected in parallel an amount of current delivered by the array is proportional to a number of the at least two multiferroic stacks connected in parallel.

5. The sensor according to claim 4, wherein the at least two multiferroic stacks in the array are separated by gaps and mounted on a ground plane.

6. The sensor according to claim 1, wherein the magnetostrictive material comprises one of Terfenol or nickel.

7. The sensor according to claim 1, wherein the magnetostrictive material is one of magnetically biased or not magnetically biased.

8. The sensor according to claim 1, wherein the magnetostrictive material is less than one electrical skin depth.

9. The sensor according to claim 1, wherein the piezoelectric material layers are polarized in a direction perpendicular to a ground plane of the antenna/sensor.

10. The sensor according to claim 1, wherein the piezoelectric material comprises one of zirconium titrate (PZT) or lead-magnesium-niobium-Ti—

O (PMN-PT).

11. The sensor according to claim 1, further comprising a thickness ratio of the magnetostrictive material layers to the piezoelectric material layers being related to a relative mechanical modulii of the layers.

12. The sensor according to claim 11, wherein a thickness ratio of the magnetostrictive material layers to the piezoelectric material layers comprises ½

.

13. An aircraft comprising:

a skin; and

an antenna including a multiferroic sensor, the multiferroic sensor comprising a multiferroic stack residing on an outside of the skin, the multiferroic stack comprising multiple connected multiferroic layer-pairs, each multiferroic layer-pair comprising an alternating layer of a magnetostrictive material and a piezoelectric material bonded together enabling a high signal sensitivity, a magnetic field of an incident signal causing mechanical strain in the magnetostrictive material layers that strains adjacent piezoelectric material layers producing an electrical voltage in each multiferroic layer-pair proportional to the incident signal,

wherein an output of the multiferroic sensor comprises the electrical voltage amplified proportional to a total number of multiple connected multiferroic layer-pairs in the multiferroic stack.

14. The aircraft according to claim 13, wherein the antenna further comprises a receiver, the receiver amplifying and processing the multiferroic sensor output.

15. The aircraft according to claim 13, wherein the antenna further comprises a matching circuit connected between the multiferroic sensor and the receiver, the matching circuit matching an impedance of the multiferroic sensor to an impedance of the receiver.

16. The aircraft according to claim 13, wherein a length and width of the multiferroic stack are a size allowing the incident signal'"'"'s magnetic field to penetrate an interior of the multiferroic stack from the sides.

17. The aircraft according to claim 13, wherein a length and width of the multiferroic stack are a size causing a mechanical resonance that is at least one of higher than an intended antenna operating frequency of the antenna or at the intended antenna operating frequency of the antenna.

18. The aircraft according to claim 13, further comprising the multiferroic sensor comprising an array of at least two multiferroic stacks, the at least two multiferroic stacks being connected at least one of in series or in parallel, wherein when the at least two multiferroic stacks are connected in series an amount of voltage delivered by the array is proportional to a number of the at least two multiferroic stacks connected in series, and wherein when the at least two multiferroic stacks are connected in parallel an amount of current delivered by the array is proportional to a number of the at least two multiferroic stacks connected in parallel.

19. The aircraft according to claim 13, wherein the at least two multiferroic stacks in the array are separated by gaps and mounted on a ground plane.

20. An antenna comrprising:

a multiferroic sensor, the multiferroic sensor comprising a multiferroic stack residing on an outside of the skin, the multiferroic stack comprising multiple connected multiferroic layer-pairs, each multiferroic layer-pair comprising an alternating layer of a magnetostrictive material and a piezoelectric material bonded together enabling a high signal sensitivity, a magnetic field of an incident signal causing mechanical strain in the magnetostrictive material layers that strains adjacent piezoelectric material layers producing an electrical voltage in each multiferroic layer-pair proportional to the incident signal, an output of the multiferroic sensor comprising the electrical voltage amplified proportional to a total number of multiple connected multiferroic layer-pairs in the multiferroic stack;

a receiver, the receiver amplifying and processing the multiferroic sensor output; and

a matching circuit connected between the multiferroic sensor and the receiver, the matching circuit matching an impedance of the multiferroic sensor to an impedance of the receiver.