다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

In this chapter, we will restrict our attention to the ferrites and a few other closely related materials. The great interest in ferrites stems from their unique combination of a spontaneous magnetization and a high electrical resistivity. The observed magnetization results from the difference in the magnetizations of two non-equivalent sub-lattices of the magnetic ions in the crystal structure. Materials of this type should strictly be designated as “ferrimagnetic” and in some respects are more closely related to anti-ferromagnetic substances than they are to ferromagnetics in which the magnetization results from the parallel alignment of all the magnetic moments present. We shall not adhere to this special nomenclature except to emphasize effects, which are due to the existence of the sub-lattices.

Ferromagnetic materials

Introduction to Electromagnetic Compatibility

Nickel Spinel Ferrites: A review

How to apply the moment method to wire antenna analysis evaluation of the basic performance of microstrip antennas key points in the design and measurement of microstrip antennas analysis of planar inverted-F antennas and antenna design for portable radio equipment design and analysis of small-aperture antennas design and measurement of small AM broadcasting antennas mutual coupling effects between antenna elements on antenna performance some considerations of small antenna measurements.

Analysis, design, and measurement of small and low-profile antennas

Structural refinement, optical and microwave dielectric properties of BaZrO3

Structural and microwave characterization of Ni0.2CoxZn0.8−xFe2O4 for antenna applications

Structural, microwave dielectric properties and dielectric resonator antenna studies of Sr(ZrxTi1―x)O3 ceramics

A low-profile planar four-element MIMO antenna is proposed in this paper that can be integrated inside wireless handheld devices. Every unit antenna is made of simple planar L-shaped monopole placed over etched non-ground area of 10 × 5 mm2. The optimized antenna elements cover three 5G New Radio bands falling within C-band: n77 band (3.3–4.2 GHz), n78 band (3.3–3.8 GHz) and n79 band (4.4–5 GHz), with isolation better than 18.8 dB, without the requirement of any additional decoupling structure. The designed antenna is fabricated on FR4 substrate of dimension 120 × 65 × 1.6 mm3. Antenna characteristics regarding reflection coefficient, mutual coupling, radiation pattern and gain are measured and discussed. The envelop correlation coefficient is computed and is lower than 0.018 for the entire range of frequency under consideration. The simplicity and compactness of the proposed MIMO antenna provides adequate space for integration of other circuits inside handheld mobile terminal. Further the integration with lower generation antennas are investigated; the result indicates that the placement of the proposed antenna system on the two long arms of ground plane offer adequate space for integration of lower generation antenna without adversely affecting each other’s performance.

Design and Development of Low Profile MIMO Antenna for 5G New Radio Smartphone Applications

Structural, vibrational and microwave dielectric properties of Nickel-Copper-Zinc ferrite (Ni0.2CuxZn0.8−xFe2O4) ceramics have been presented in this paper. Samples have been prepared using conventional auto-combustion method. The X-ray diffraction (XRD) results confirmed the ferrite samples to be of cubic spinel structure, which further was validated by Fourier transform infrared (FT-IR) and Raman spectroscopy. The relative permittivity (εr) increased from 7.474 to 8.132 with successive increase in Cu content. The observed and calculated permittivity using ClausiusMossoitti relation have been in good agreement. The temperature coefficient of resonant frequency (τf ) decreased from −75.85 ppm/◦C to −32.12 ppm/◦C with increase in successive Cu content. The relative permeability (μr) have been calculated by using the Nicholson-Ross-Weir conversion technique. Using Ni0.2Cu0.2Zn0.6Fe2O4 sample the ferrite resonator antennas have been designed in three different shapes. The experimental and theoretical characteristics of the antennas have been compared and a good agreement has been achieved.

https://www.jpier.org/pierb/pierb57/11.13090705.pdf

Vibha Rani Gupta

Papers

Structural refinement, optical and microwave dielectric properties of BaZrO3

Structural and microwave characterization of Ni0.2CoxZn0.8−xFe2O4 for antenna applications

Structural, microwave dielectric properties and dielectric resonator antenna studies of Sr(ZrxTi1―x)O3 ceramics

Design and Development of Low Profile MIMO Antenna for 5G New Radio Smartphone Applications

Microwave Dielectric Properties of Ni 0.2 Cu X Zn 0.8-X FE 2 O 4 for Application in Antenna