Microwave Response of Gd-Doped YIG Based Y-Junction Stripline Circulator for Use at Very High Frequencies

2020 ◽  
Vol 855 ◽  
pp. 274-279
Author(s):  
Handoko Subawi ◽  
Syoni Soepriyanto
Keyword(s):  
Magnetic Properties ◽  
Insertion Loss ◽  
Rare Earth Oxide ◽  
Soft Magnetic Materials ◽  
Microwave Response ◽  
Soft Magnetic ◽  
High Frequencies ◽  
Dry Pressing ◽  
Very High Frequencies ◽  
Very High

This study aimed to evaluate Fe2O3 based magnetic ferrite performance and its composition using Rare Earth Oxide (REO) of Yttrium as dopant and Gadolinium as co-dopant elements. Lot of specimens were prepared through dry pressing technique, and sintered into the high temperature tube furnace up to 1450°C. Sintering duration of 5 hours results the best magnetic properties. The existence of Gadolinium element tends to improve magnetic properties of magnetic ferrite Gd-doped YIG structure. Remacomp brand Magnet-Physik was used to determine the characteristics of soft magnetic materials in the measurement frequency range of 10 Hz to 70 kHz. Microwave response was measured using the Vector Network Analysis to provide insertion loss and isolation data. The obtained insertion loss of Gd0.75Y2.25Fe5O12 is 0.4270 dB (at 3.7 GHz) and 0.2455 dB (at 4.2 GHz), while the isolation value is 11.3840 dB (at 3.7 GHz) and 17.8250 dB (at 4.2 GHz). The further experiment will be carried out to improve the microwave response and better magnetic properties of Gd-doped YIG structure.

scholarly journals Survey on reconfigurable intelligent surfaces below 10 GHz

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Visa Tapio ◽  
Ibrahim Hemadeh ◽  
Alain Mourad ◽  
Arman Shojaeifard ◽  
Markku Juntti
Keyword(s):  
Magnetic Properties ◽  
Wireless Communication ◽  
Electromagnetic Waves ◽  
Wireless Systems ◽  
Basic Operation ◽  
Review Of The Literature ◽  
High Frequencies ◽  
Very High Frequencies ◽  
Very High

AbstractReconfigurable intelligent surface (RIS) is a programmable structure that can be used to control the propagation of electromagnetic waves by changing the electric and magnetic properties of the surface. By placing these surfaces in an environment, the properties of radio channels can be controlled. This opens up new opportunities to improve the performance of wireless systems. In this paper, the basic operation of antenna array and metasurface based RIS is described. While the current long term (6G) research on RIS often prioritizes very high frequencies from tens to hundreds of GHz, this paper puts emphasis rather on operating frequencies below 10 GHz which promise a much faster to market track for RIS applications. For this purpose, review of the literature on the use of RIS in wireless communication applications operating below 10 GHz frequency band is provided.

scholarly journals The Structure and Magnetic Properties of Rapidly Quenched Fe72Ni8Nb4Si2B14 Alloy

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 5
Author(s):  
Lukasz Hawelek ◽  
Tymon Warski ◽  
Patryk Wlodarczyk ◽  
Marcin Polak ◽  
Przemyslaw Zackiewicz ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Relaxation Process ◽  
Glassy State ◽  
Diffraction Method ◽  
Soft Magnetic Materials ◽  
Process Time ◽  
Complex Permeability ◽  
Soft Magnetic ◽  
Conventional Heat Treatment ◽  
Glass Relaxation

The complex structural and magnetic studies of the annealed rapidly quenched Cu-free Fe72Ni8Nb4Si2B14 alloy (metallic ribbons form) are reported here. Based on the calorimetric results, the conventional heat treatment process (with heating rate 10 °C/min and subsequent isothermal annealing for 20 min) for wound toroidal cores has been optimized to obtain the least lossy magnetic properties (for the minimum value of coercivity and magnetic core losses at 50 Hz). For optimal conditions, the complex permeability in the 104–108 Hz frequency range together with core power losses obtained from magnetic induction dependence up to the frequency of 400 kHz was successfully measured. The average and local crystal structure was investigated by the use of the X-ray diffraction method and the transmission electron microscopy observations and proved its fully glassy state. Additionally, for the three temperature values, i.e., 310, 340 and 370 °C, the glass relaxation process study in the function of annealing time was carried out to obtain a deeper insight into the soft magnetic properties: magnetic permeability and cut-off frequency. For this type of Cu-free soft magnetic materials, the control of glass relaxation process (time and temperature) is extremely important to obtain proper magnetic properties.

An ammeter for very high frequencies

1930 ◽  
Vol 68 (401) ◽  
pp. 556-559
Author(s):  
C.L. Fortescue ◽  
L.A. Moxon
Keyword(s):  
High Frequencies ◽  
Very High Frequencies ◽  
Very High

scholarly journals Idiotypic analysis of potential and available repertoires in the arsonate system.

1984 ◽  
Vol 160 (1) ◽  
pp. 1-11 ◽  
Author(s):  
M Slaoui ◽  
O Leo ◽  
J Marvel ◽  
M Moser ◽  
J Hiernaux ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
B Cells ◽  
Keyhole Limpet Hemocyanin ◽  
High Frequencies ◽  
Specific Subset ◽  
A Minor ◽  
Very High Frequencies ◽  
Very High ◽  
Limiting Dilution

We have shown that, by suitable idiotypic manipulation, BALB/c mice can express the major cross-reactive idiotype (CRI) of A/J mice in response to azophenylarsonate (Ars). In order to know if the CRIA idiotype is present in the potential repertoire of BALB/c before any intentional selection, we used polyclonal activation in vitro and limiting dilution analysis. The readout was done with two monoclonal anti-CRIA antibodies that recognize distinct idiotopes on a CRIA+ A/J germline-encoded monoclonal antibody. We studied the frequency of CRIA+ lipopolysaccharide (LPS)-reactive cells in the spleens of nonimmune and immune A/J mice and in the spleens of naive and manipulated (i.e., producing CRIA+ antibodies) BALB/c mice. A/J and BALB/c naive individuals presented very high frequencies of Ars-specific B cells while the frequency of CRIA+ B cells was only a minor subset (0.5%) of the total Ars-specific subset in the two strains. When A/J mice were immunized with Ars-keyhole limpet hemocyanin, a clear preferential expansion of the CRIA+ minor subset of A/J mice was observed (100x). No such enhancement was observed in BALB/c mice similarly treated. Manipulated BALB/c mice presented a higher frequency of CRIA+ anti-Ars B cells than naive or antigen-immunized BALB/c individuals.

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