High-Frequency Tunneling Magnetic Loss in Soft Ferrites

2007 ◽  
Vol 43 (3) ◽  
pp. 968-973 ◽  
Author(s):  
Waseem A. Roshen
2020 ◽  
Vol 10 (15) ◽  
pp. 5392 ◽  
Author(s):  
Won Bin Park ◽  
Young-Mi Park ◽  
Keum Cheol Hwang

In this letter, an electrically small Spidron fractal loop antenna operating in the VHF band is proposed. The ferrite material, which consists of a nickel-zinc combination, is loaded into inside of the loop antenna to increase the gain of the antenna in the low frequency band. To minimize the magnetic loss of the ferrite in the high frequency band, the amount and configuration of the ferrite are optimized using a genetic algorithm. Through this optimization step, the amount of the ferrite is decreased to 37.5% and the gain of the antenna in the high frequency band is improved. The size of the proposed antenna is 0.0242 × 0.0242 × 0.0051 λL3 at the lowest operating frequency. The proposed antenna was fabricated to verify the performance, and the simulated and measured results are in good agreement. The measured peak gains varied from −31.6 to −1.9 dBi within the measured frequency band. To examine the performance of the proposed antenna mounted on an unmanned aerial vehicle model (UAV), the antenna on a UAV was also simulated and the results were discussed. The simulated realized peak gains of the antenna on the UAV and on flat ground are similar.


1997 ◽  
Vol 07 (C1) ◽  
pp. C1-441-C1-442
Author(s):  
K. Berthou-Pichavant ◽  
F. Liorzou ◽  
Ph. Gelin ◽  
M. Le Floch

2017 ◽  
Vol 898 ◽  
pp. 1625-1630 ◽  
Author(s):  
Guang Qiang Zhang ◽  
Hang Rong Dong ◽  
Zong Zhen Li ◽  
Shao Xiong Zhou ◽  
Yu Wang ◽  
...  

Three-dimensional flower-like nickel-ferrite composites were successfully synthesized via decomposition of the nickel-iron alkoxide precursors by varying the ratio of iron and nickel ion in the solution. The overall morphology and size of the particles had no obvious change compared with the precursors. The high-frequency absorption properties of the composites were investigated in a frequency range of 2-18 GHz. The reflection loss and bandwidth varied with the nickel ratio and thicknesses of the compositions, showing valuable prospect in high-frequency wave attenuation. The wave absorbing mechanism was also discussed, which could be attributed to the dielectric loss, magnetic loss, and the synergetic effect.


Author(s):  
Janis Jankovskis ◽  
Nikolajs Ponomarenko ◽  
Pavels Narica

The problem under examination is the magnetic loss of polycrystalline ferrites. Their total loss include: hysteresis, eddy current and anomalous (AN) or excess ones. The mentioned first two losses more or less adequately are covered by modified Steinmetz equation whereas AN loss is less well understood. Conceptually this loss is defined by the components of complex permeability spectra of ferrites which as a rule are experimentally obtained. Large body of these experimental spectra shows a great variety of forms and specific features. This variety is the main reason why there still is not adequate analytic presentation of AN loss. It is shown in the research that important progress is possible to achieve in analytic presentation of AN loss on the basis of realistic account of microstructure of polycrystalline ferrites and dividing the variety of all samples into subgroups according to their actual structure.


2008 ◽  
Vol 148 (1-3) ◽  
pp. 136-140 ◽  
Author(s):  
A.K. Subramani ◽  
N. Matsushita ◽  
T. Watanabe ◽  
M. Tada ◽  
M. Abe ◽  
...  

2012 ◽  
Vol 435 (1) ◽  
pp. 18-29
Author(s):  
Hsing-I Hsiang ◽  
Chi-Shiung Hsi ◽  
Xiao Ci Hsu

2007 ◽  
Vol 101 (9) ◽  
pp. 09M522 ◽  
Author(s):  
Waseem A. Roshen
Keyword(s):  

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