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.

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.

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.

A Genetically Marked I Element in Drosophila melanogaster Can Be Mobilized When ORF2 Is Provided in trans

Genetics ◽  
1998 ◽  
Vol 148 (1) ◽  
pp. 267-275
Author(s):  
Isabelle Busseau ◽  
Sophie Malinsky ◽  
Maria Balakireva ◽  
Marie-Christine Chaboissier ◽  
Danielle Teninges ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Heat Shock ◽  
Reverse Transcriptase ◽  
Germ Line ◽  
Ltr Retrotransposons ◽  
Low Frequencies ◽  
High Frequencies ◽  
In Trans ◽  
Very High Frequencies ◽  
Very High

Abstract I factors in Drosophila melanogaster are non-LTR retrotransposons similar to mammalian LINEs. They transpose at very high frequencies in the germ line of SF females resulting from crosses between reactive females, devoid of active I factors, and inducer males, containing active I factors. The vermilion marked IviP2 element was designed to allow easy phenotypical screening for retrotransposition events. It is deleted in ORF2 and therefore cannot produce reverse transcriptase. IviP2 can be mobilized at very low frequencies by actively transposing I factors in the germ line of SF females. This paper shows that IviP2 can be mobilized more efficiently in the germ line of strongly reactive females in the absence of active I factors, when it is trans-complemented by the product of ORF2 synthesized from the hsp70 heat-shock promoter. This represents a promising step toward the use of marked I elements to study retrotransposition and as tools for mutagenesis.

scholarly journals Field Measurements of Dielectric Absorption in Antarctic Ice and Snow at Very High Frequencies

1968 ◽  
Vol 7 (49) ◽  
pp. 89-94 ◽  
Author(s):  
M. E. R. Walford
Keyword(s):  
Impurity Content ◽  
Field Measurements ◽  
Relaxation Mechanism ◽  
Absorption Bands ◽  
High Frequencies ◽  
Dielectric Absorption ◽  
Antarctic Snow ◽  
Radio Frequencies ◽  
Very High Frequencies ◽  
Very High

AbstractField measurements are presented of dielectric absorption in Antarctic snow and ice at frequencies of a few hundred megahertz. They are compared with measurements by other authors at very high frequencies. The dielectric absorption in ice at these frequencies is accounted for in terms of absorption bands both at radio frequencies and in the infrared. Bands at radio frequencies are caused by a relaxation mechanism which depends upon the temperature and the impurity content of the ice. These two factors are therefore included in an account of the dielectric absorption in ice at very high frequencies.

scholarly journals Ephemeral states in protein folding under force captured with a magnetic tweezers design

2019 ◽  
Vol 116 (16) ◽  
pp. 7873-7878 ◽  
Author(s):  
Rafael Tapia-Rojo ◽  
Edward C. Eckels ◽  
Julio M. Fernández
Keyword(s):  
Magnetic Field ◽  
Molten Globule ◽  
Magnetic Tweezers ◽  
Protein L ◽  
High Frequencies ◽  
Electric Signals ◽  
Very High Frequencies ◽  
The Magnetic Field ◽  
Very High ◽  
Unique Capability

Magnetic tape heads are ubiquitously used to read and record on magnetic tapes in technologies as diverse as old VHS tapes, modern hard-drive disks, or magnetic bands on credit cards. Their design highlights the ability to convert electric signals into fluctuations of the magnetic field at very high frequencies, which is essential for the high-density storage demanded nowadays. Here, we twist this conventional use of tape heads to implement one in a magnetic tweezers design, which offers the unique capability of changing the force with a bandwidth of ∼10 kHz. We calibrate our instrument by developing an analytical expression that predicts the magnetic force acting on a superparamagnetic bead based on the Karlqvist approximation of the magnetic field created by a tape head. This theory is validated by measuring the force dependence of protein L unfolding/folding step sizes and the folding properties of the R3 talin domain. We demonstrate the potential of our instrument by carrying out millisecond-long quenches to capture the formation of the ephemeral molten globule state in protein L, which has never been observed before. Our instrument provides the capability of interrogating individual molecules under fast-changing forces with a control and resolution below a fraction of a piconewton, opening a range of force spectroscopy protocols to study protein dynamics under force.

Sign in / Sign up

Export Citation Format

Share Document