Dielectric resonator antenna: Operation of the magnetodielectric composites Cr0.75Fe1.25O3 (CRFO)/Fe0.5Cu0.75Ti0.75O3 (FCTO)

Rocha, H.H.B.; Freire, Francisco Nivaldo Aguiar; Costa, Rafael Santiago da; Sohn, R. S. T. M.; Orjubin, G.; Junqueira, Cynthia; Cordaro, T.; Sombra, A. S. B.

doi:10.1002/mop.22160

Cited by 9 publications

(4 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the numerical study, it was observed that the increase of the air gaps leads to a frequency shift upward and a decrease of the resistance at resonance. Such behavior has been explained in [13,14]. The resistance R of the first resonant frequency of each DRA is also indicated in table 1 and figure 3.…”

Section: Resultsmentioning

confidence: 56%

“…In an experiment introduced by Long [7], the dielectric resonators are excited by a wire antenna above a ground plane. The configuration of the cylindrical DRAs is shown in figure 1 [13]. The DRA is placed above a conducting ground plane (the ground plane is made of copper, with 35.5 cm × 30 cm × 2.14 mm), and excited by a coaxial probe (L = 9 mm).…”

Section: Antenna Configurationmentioning

confidence: 99%

See 1 more Smart Citation

Electrical properties of the electroceramic composite in the microwave frequency range: Pb(Fe_0.5Nb_0.5)O₃(PFN)–Cr_0.75Fe_1.25O₃(CRFO)

et al. 2008

View full text Add to dashboard Cite

In this paper, a new electroceramic composite [Pb(Fe 0.5 Nb 0.5 )O 3 (PFN)] Z [Cr 0.75 Fe 1.25 O 3 (CRFO)] 100−Z (Z = 0, 10) is investigated in the microwave (MW) frequency range. The dielectric permittivity and loss in the region of 4-8 GHz (G and H MW bands) were studied. The performance of cylindrical resonator antennas based on CRFO100 and on PFN10 was examined. The experimental and theoretical results of the dielectric resonator antenna (DRA) such as return loss, bandwidth, input impedance and radiation patterns are in good agreement for both composites: PFN10 (10% PFN + 90% CRFO) and CRFO100 (100% CRFO). A numerical validation was made considering an air gap between the dielectric resonator and the metallic conductors. The PFN10 matrix composite PFN10 (10% PFN + 90% CRFO) presents the highest dielectric permittivity (9.9 at 4.44 GHz) and the lowest bandwidth (9.9%). The CRFO100 phase (100% CRFO) presents a dielectric permittivity of 8.35 at 4.67 GHz and a bandwidth of 11.8%. The Hakki-Coleman procedure was also used in this study. The dielectric permittivity of 8.35 (tan δ = 1 × 10 −3 ) at 7.94 GHz was obtained for CRFO100. The PFN10 presents a dielectric permittivity of 10.17 (tan δ = 4.9 × 10 −3 ) at 7.05 GHz. These measurements confirm the possible use of such material for small DRAs.

show abstract

Section: Resultsmentioning

confidence: 56%

Section: Antenna Configurationmentioning

confidence: 99%

Electrical properties of the electroceramic composite in the microwave frequency range: Pb(Fe_0.5Nb_0.5)O₃(PFN)–Cr_0.75Fe_1.25O₃(CRFO)

et al. 2008

View full text Add to dashboard Cite

show abstract

“…Materials with mixed permittivity and permeability present a problem to all TCM solution sets. Even though magnetic materials may not be as common as dielectric materials in antenna design, they can play a vital role in antenna miniaturization [35] and absorbing materials [36]. In recent years, nano-ferrites have been proven useful at higher frequencies, with reduced loss while maintaining high permeability [37] These new materials, while still lossy, can significantly reduce the resonant frequency of multi-GHz dielectric resonator antennas (DRAs).…”

Section: Comparison Of Sie Modes To Vie Modesmentioning

confidence: 99%

Computational Analysis and Verifications of Characteristic Modes in Real Materials

Miers

Lau

2016

IEEE Trans. Antennas Propagat.

View full text Add to dashboard Cite

Despite its long history, the Theory of Characteristic Modes has only been utilized in antenna design for perfect electric conductors. This is due to computational problems associated with dielectrics and magnetic materials. In particular, the symmetric form of the PMCHWT surface formulation for the Method of Moments (MoM) solves for both external (real) and internal (non-real) resonances of a structure. The external resonances are the characteristic modes, whereas the internal resonances are not. This article proposes a new post-processing method capable of providing unique and real characteristic modes in all physical mediums, including lossy magnetic and dielectric materials. The method removes the internal resonances of a structure by defining a minimum radiated power, which is found through utilizing the physical bounds of the structure. The characteristic modes found using the proposed method are verified through the use of a MoM volume formulation, time domain antenna simulations, and experiments involving multiple antenna prototypes.

show abstract

“…As a result, it seems to be a candidate for devising a promising spintronic material when incorporating Cr 4+ ions with 3d 2 spins in a ZrO 2 -like dielectric oxide. In particular, such magnetoceramics can be explored in developing devices such as dielectric resonator antenna, solid electrolyte cell, magnetic hydrodynamic generator, magnetic sensor, phosphor, magnetic switch, and spin-charge transducer [7,[11][12][13]. Using a polymer precursor route [7], Ram demonstrated synthesis of Zr 1-x Cr x O 2 , with the Cr 4+ /Cr 3+ content as much as x = 0.2, stabilized in a cubic (c)-ZrO 2 -like polymorph.…”

Section: Introductionmentioning

confidence: 99%

Magnetism in a Spintronic Compound Zr0.8Cr0.2O2 of Small Crystallites

Sengupta

Misra

Ram

2014

JNanoR

View full text Add to dashboard Cite

A transition metal ion Cr4+(3d2 spins) doped ZrO2 of small crystallites presents tailored magnetic, electrical and optical properties useful for magnetodielectric and spintronic applications. A liquid polymer precursor gel (Cr4+ and Zr4+ complex with glycerol) when heated in an autoclave at a small pressure 0.6-0.7 atm at 420–470 K results in a compound Zr0.8Cr0.2O2 with an average 5 nm crystallite size of a stabilized cubic (c)-ZrO2-type phase (after 2 h annealing at 773 K in air). A broad Raman band is observed at ~300 cm-1 in acoustic and transverse optic phonons characteristic of the c-ZrO2-type structure, with a prominent O–Cr–O stretching band at 878 cm-1 in a ferromagnetic order. A CrO2/Cr2O3 surface layer exhibits two weak bands at ~1011 cm-1 and 1032 cm-1. The sample exhibits an ‘S’-shaped ferromagnetic hysteresis loop (does not saturate below 60 kOe fields) at 5 K, with a magnetization M = 85.79 emu/g (in the CrO2 part) at 60 kOe and coercivity Hc = 100 Oe. With warming above 5 K, the loop converges progressively with only a weak ferromagnetism at room temperature, M = 9.08 emu/g and Hc = 54.2 Oe. As a pinning barrier, the uncompensated spins in the surface layer supports coercivity at low temperature. A model magnetic structure describes the magnetic properties in correlation to the microstructure.

show abstract

Dielectric resonator antenna: Operation of the magnetodielectric composites Cr_0.75Fe_1.25O₃ (CRFO)/Fe_0.5Cu_0.75Ti_0.75O₃ (FCTO)

Abstract: ABSTRACT:

Cited by 9 publications

References 11 publications

Electrical properties of the electroceramic composite in the microwave frequency range: Pb(Fe_0.5Nb_0.5)O₃(PFN)–Cr_0.75Fe_1.25O₃(CRFO)

Electrical properties of the electroceramic composite in the microwave frequency range: Pb(Fe_0.5Nb_0.5)O₃(PFN)–Cr_0.75Fe_1.25O₃(CRFO)

Computational Analysis and Verifications of Characteristic Modes in Real Materials

Magnetism in a Spintronic Compound Zr<sub>0.8</sub>Cr<sub>0.2</sub>O<sub>2</sub> of Small Crystallites

Contact Info

Product

Resources

About

Dielectric resonator antenna: Operation of the magnetodielectric composites Cr0.75Fe1.25O3 (CRFO)/Fe0.5Cu0.75Ti0.75O3 (FCTO)

Abstract: ABSTRACT:

Cited by 9 publications

References 11 publications

Electrical properties of the electroceramic composite in the microwave frequency range: Pb(Fe0.5Nb0.5)O3(PFN)–Cr0.75Fe1.25O3(CRFO)

Electrical properties of the electroceramic composite in the microwave frequency range: Pb(Fe0.5Nb0.5)O3(PFN)–Cr0.75Fe1.25O3(CRFO)

Computational Analysis and Verifications of Characteristic Modes in Real Materials

Magnetism in a Spintronic Compound Zr<sub>0.8</sub>Cr<sub>0.2</sub>O<sub>2</sub> of Small Crystallites

Contact Info

Product

Resources

About

Dielectric resonator antenna: Operation of the magnetodielectric composites Cr_0.75Fe_1.25O₃ (CRFO)/Fe_0.5Cu_0.75Ti_0.75O₃ (FCTO)

Electrical properties of the electroceramic composite in the microwave frequency range: Pb(Fe_0.5Nb_0.5)O₃(PFN)–Cr_0.75Fe_1.25O₃(CRFO)

Electrical properties of the electroceramic composite in the microwave frequency range: Pb(Fe_0.5Nb_0.5)O₃(PFN)–Cr_0.75Fe_1.25O₃(CRFO)