Microwave Absorption Study of Nano Synthesized Strontium Ferrite Particles in X Band
Microwave ferrites require high coercivity for their use as microwave absorbers. Strontium hexaferrite is one of the best material due to its magnetic properties , high coercivity, large unilateral magnetic anisotropy and very low cost in comparison to others make it suitable for the use as microwave components specifically microwave absorber .Strontium nano hexa ferrites were successfully synthesized through chemical co-precipitation method. The synthesized nanostructure was characterized by X-Ray powder diffraction(XRD) and fourier transform infrared spectroscopy (FTIR).The XRD result shows the shift from amorphous to crystalline after the calcination of sample at 600 0 C.The behaviour of ferrite as microwave absorber was also studied for X band of frequencies.
MICROWAVE ABSORPTION STUDY OF MANGANESE FERRITE IN X-BAND RANGE PREPARED BY SOLID STATE REACTION METHOD
A research to study the microwave absorption properties of manganese ferrite in the X-band range have been conducted by using high energy milling technique. The synthesis of manganese ferrite (Mn 1+x Fe 2-x O 4 ) was performed using solid state reaction method with the material composition (x)MnO : (2-x) Fe 2 O 3 (x = 0.25; 0.50; 0.75 and 1.0) according to the molar ratio. This powder mixture was being milled for 10 hours then sintered at 1200 °C temperature for 3 hours. Material characterization was done by using FTIR spectroscopy (Fourier Transform Infra Red Spectroscopy) to observe the functional group, XRD (X-ray diffractometer) for phase identification, SEM (Scanning Electron Microscope) for surface morphology observation and VNA (Vector Network Analyzer) to determine the ability of materials to absorb microwaves. Analysis by FTIR showed two absorption peaks in the range of ~ 446 and ~ 557 cm -1 were associated with the octahedral and tetrahedral sites in structure of MnFe 2 O 4 . Phase identification by XRD showed that the increasing content of Mn (above x=0.25 composition) caused a single phase of MnFe 2 O 4 turned into two phases (MnFe 2 O 4 and Fe 2 O 3 ), this results correspond to the SEM results which showed the morphological structure of those compositions are inhomogenous. The Absorption of microwaves was also decreased along with the increasing of Mn content. The maximum refflection loss was reached in the composition of Mn (x=0.0) which equal to ~ 82%, while for the composition of Mn (x=0.0) only reached ~ 55%.
Designing rectangular patch antenna using the neurospectral method
This paper presents a new method for developing computer-aided design (CAD) models, using spectral domain (SD) formulation. Using the artificial neural network (ANN) technique, a combination of continuous function and delta functions constitutes the spectral domain Green's functions. We obtain closed-form formulas for integration involving these equations. Another neural network relates different antenna parameters. Utilizing the reverse modeling for patch dimension determination, it becomes useful as a CAD model for patch antenna design. Designs, of simple rectangular patch antennas, serve as illustration of this method.