Magnetodielectric Metamaterials and Articles Including Magnetodielectric Metamaterials

Patent metadata

Field	Value
Publication number	US-2020119451-A1
Application number	US-201916600292-A
Country	US
Kind code	A1
Filing date	Oct 11, 2019
Priority date	Oct 11, 2018
Publication date	Apr 16, 2020
Grant date	—

Abstract

Magnetodielectric (MD) metamaterials have a magnetodielectric (MD) substrate of a ferrite composition or composite having a characteristic impedance matching an impedance of free space and at least one frequency selective surface (FSS). The FSS has a plurality of frequency selective surface elements disposed in a pattern and supported on the MD substrate. The FSS has a conducting composition and is configured to permit one or more of transmission, reflection, or absorption at a selected resonant frequency or selected frequency band. Articles incorporating magnetodielectric metamaterials are provided.

First claim

What is claimed is:

1 . A magnetodielectric (MD) metamaterial comprising:
a magnetodielectric (MD) substrate comprising a ferrite composition or composite having a characteristic impedance matching an impedance of free space within 5%; and at least one frequency selective surface (FSS) having a plurality of frequency selective surface elements disposed in a pattern and supported on the MD substrate, the FSS comprising a conducting composition, and configured to permit one or more of transmission, reflection, or absorption at a selected resonant frequency or selected frequency band.

2 . The MD metamaterial of claim 1 , wherein a real permittivity of the ferrite composition or composite is equal to a real permittivity of the ferrite composition or composite within 10%.

3 . The MD metamaterial of claim 1 , wherein the frequency selective surface element is selected from the group consisting of loop type, center-connected type, N-pole type, solid interior type, and plate type, and combinations thereof

4 . The MD metamaterial of claim 1 , wherein the ferrite composition or composite is a hexaferrite composition selected from the group consisting of a Z-type phase hexaferrite, a Y-type phase hexaferrite, an M-type phase hexaferrite, a W-type hexaferrite, an X-type hexaferrite, and a U-type hexaferrite, and combinations thereof.

5 . The MD metamaterial of claim 1 , wherein the ferrite composition or composite is a spinel ferrite of stoichiometry (TM)Fe 2 O 4 , where TM is a transition metal selected from the group consisting of iron, cobalt, manganese, nickel, zinc, copper, magnesium, chromium, and titanium of valence +1, +2, +3, or +4, and combinations thereof.

6 . The MD metamaterial of claim 1 , wherein the ferrite composition or composite comprises a hexaferrite composition comprising a Z-type hexaferrite phase, a Y-type hexaferrite phase, or both a Z-type hexaferrite phase and a Y-type hexaferrite phase.

7 . The MD metamaterial of claim 1 , wherein the ferrite composition or composite comprises a hexaferrite composition comprising an oxide structure having iron, cobalt, zinc, nickel, chromium, manganese, magnesium, and/or titanium and one or more of barium, strontium, iridium, hafnium, and molybdenum having a composition comprising Ba 3 Co 2-x Fe 24-2x O 41 , where x=0.05 to 0.20 of quadrivalent iridium, hafnium, and molybdenum.

8 . The MD metamaterial of claim 1 , wherein the ferrite composition or composite comprises Ba(CoTi) 2 Fe 9.6 O 19 and an amount of Bi 2 O 3 , the amount Bi 2 O 3 ranging between 0 and 10 wt %.

9 . The MD metamaterial of claim 1 , wherein the ferrite composition or composite comprises a hexaferrite composition comprising Co2Z and Co2Y ferrite particles, having nominal compositions Ba 3 Co 2 Fe 24 O 41 and Ba 2 Co 2 Fe 12 O 22 , respectively.

10 . The MD metamaterial of claim 1 , wherein the ferrite composition or composite comprises a spinel ferrite comprising Ni 0.5 Zn 0.3 Co 0.2 Fe 2 O 4 (NiZnCo) with B 2 O 3 —Bi 2 O 3 —SiO 2 —ZnO (BBSZ) glass additions.

11 . The MD metamaterial of claim 1 , wherein the ferrite composition or composite comprises a hexaferrite composite comprising Ba(CoTi) 1.2 Fe 9.6 O 19 M-type hexaferrites and an amount of Bi 2 O 3 , wherein the amount of Bi 2 O 3 ranges between 1 and 20 wt. %.

12 . The MD metamaterial of claim 1 , wherein the FSS comprises a low-pass filter, high-pass filter, bandpass filter, or bandstop filter.

13 . The MD metamaterial of claim 1 , wherein the FSS is operable at a frequency equal to or greater than 0.05 GHz.

14 . The MD metamaterial of claim 1 , wherein the FSS is operable at a frequency between about 0.05 GHz to about 2 GHz.

15 . The MD metamaterial of claim 1 , wherein the FSS and MD substrate have a magnetic loss tangent tan δ μ less than 0.40 at 50 MHz or greater bandwidth about a center frequency between about 0.05 to about 2 GHz.

16 . The MD metamaterial of claim 1 , wherein the FSS and MD substrate have a dielectric loss tangent tan δ 68 less than 0.01 over a frequency of about 0.05 to about 2 GHz.

17 . An article comprising the MD metamaterial of claim 1 .

18 . The article of claim 11 , wherein the article is a radome, an antenna substrate and/or superstrate, an electromagnetic bandgap (EBG) substrate and/or superstrate, or a coating.

19 . The article of claim 11 , further comprising a multiferroic component comprising a ferrimagnetic or ferromagnetic component, a ferroelectric component, or a ferroelastic component, or a combination thereof.

20 . The article of claim 11 , wherein the article is operable at a frequency equal to or greater than 0.05 GHz.

Assignees

• Univ Northeastern

Inventors

• Harris Vincent

Classifications

• C01G51/66

  containing alkaline earth metals, e.g. SrCoO3 · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title

• C01P2006/42

  Magnetic properties · CPC title

• C01P2006/40

  Electric properties · CPC title