Microwave permittivity and permeability of ferrite–polymer thick films

Verma, Anjali; Saxena, Abhinav; Dube, D. C.

doi:10.1016/s0304-8853(02)01569-x

Cited by 155 publications

(63 citation statements)

References 15 publications

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“…4. It can be seen that compared with the carbonyl iron, the dendritic iron has a higher complex permittivity (e), which stands for larger energy storage and loss [27]. Within the measured frequency (f) range, the real permittivity (e 0 ) fluctuates between 6.3 and 15.3, while imaginary permittivity (e 00 ) fluctuates between 3.4 and 7.6.…”

Section: Magnetic Property Of Dendritic Ironmentioning

confidence: 94%

Synthesis, magnetic and microwave electromagnetic properties of dendritic iron

Yan

Zhao

et al. 2015

Appl. Phys. A

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Iron dendritic micropines are synthesized by a hydrogen reduction, where the hematite dendritic micropines prepared by a hydrothermal method are used as starting materials. The as-obtained dendritic iron exhibits enhanced coercivity and remanent magnetization at room temperature and high complex permittivity at 2-18 GHz due to the peculiar shape anisotropy and good crystallinity. The negative imaginary permeability is observed at 14.5-18.0 GHz, suggesting it has a potential as a lefthanded material. The paraffin-based composites containing 30 wt% dendritic irons show large permittivity resulting from the charge polarization and the conductivity and have a minimal reflection loss (RL) of -37.4 dB at 7.4 GHz when the thickness (d) is 2.0 mm. The RL values less than -20 dB are obtained in the frequency range of 5.5-12.9 GHz when d increases from 0.9 to 3.0 mm.

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Section: Magnetic Property Of Dendritic Ironmentioning

confidence: 94%

Synthesis, magnetic and microwave electromagnetic properties of dendritic iron

Yan

Zhao

et al. 2015

Appl. Phys. A

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“…Some recently synthesized materials include graphene nanoribbons or metallic inclusions for use in miniaturization of electronic components [1,2], ferrite loaded polymers to increase EMI shielding [3], cellular materials such as honeycomb structures to decrease radar cross-section [4], and anisotropic materials used to enhance antenna operation [5]. Since the properties of these materials are often hard to accurately predict (due to modeling uncertainties and variability in the manufacturing process), they are usually measured in a laboratory.…”

Section: Introductionmentioning

confidence: 99%

A Waveguide Verification Standard Design Procedure for the Microwave Characterization of Magnetic Materials

Crowgey

Tang

Rothwell

et al. 2015

PIER

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Abstract-A waveguide standard is introduced for validation purposes on the measurement accuracy of electric and magnetic properties of materials at microwave frequencies. The standard acts as a surrogate material with both electric and magnetic properties and is useful for verifying systems designed to characterize engineered materials using the Nicolson-Ross-Weir technique. A genetic algorithm is used to optimize the all-metallic structure to produce a surrogate with both relative permittivity and permeability within a target range across S-band. A mode-matching approach allows the user to predict the material properties with high accuracy, and thus compensate for differences in geometry due to loose fabrication tolerances or limited availability of component parts. The mode-matching method also allows the user to design standards that may be used within other measurement bands. An example standard is characterized experimentally, the errors due to uncertainties in measured dimensions and to experimental repeatability are explored, and the usefulness of the standard as a verification tool is validated.

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“…The spinel ferrites possess properties of both magnetic materials and insulators. They can be used as electromagnetic wave absorbers or electromagnetic interference (EMI) suppressor in the MHz frequency range like the TV ghost suppressor (Green et al 1964, Goldman 1990, Verma et al 2003, Han et al 1995, Luo et al 2000, Meshram et al 2002. Ferrites are also used in camouflaging military aircrafts and missiles against radar detection (Meshram et al 2002).…”

Section: Introductionmentioning

confidence: 99%