737 research outputs found

    Communication satellite systems for Alaska

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    Technical and cost factors for implementation of Alaskan communication satellite syste

    DC-assisted microwave quenching of YBa2Cu3O7-{\delta} coplanar waveguide to a highly dissipative state

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    The paper reports on finding the effect of a strong change in the microwave losses in an HTS-based coplanar waveguide (CPW) at certain values of the input power Pin and direct current Idc. CPW on the basis of 150 nm thick YBa2Cu3O7-{\delta} epitaxial film on a single crystal MgO substrate was studied experimentally. A sharp and reversible transition of the CPW into a strongly dissipative state at the certain meanings of Pin and Idc depending on temperature was observed. Apparently the effect can be explained by self-heating of HTS structure caused by magnetic flux flow under the joint influence of MW and DC.Comment: 9 pages, 5 figures, 17 reference

    Multiresonances of quasi-trapped modes in metasurfaces based on nanoparticles of transition metal dichalcogenides

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    The features of polarization control of multiple multiresonances for quasi-trapped modes excited by synchronization of bianisotropic dipole responses in MoS2_2 disks with a hole are considered. Using the numerical calculations with analytical multipole analysis, we showed that the presence of a strong optical anisotropy of MoS2_2 nanoparticles provides an additional degree of freedom and allows to observe several resonances of electric and magnetic dipoles at once in a narrow spectral range. Based on the simulation results, we obtained the frequency dependences for the dipole polarizabilities of the MoS2_2 disk with a hole, which allow one to distinguish the contributions of the nonlocal and bianisotropic dipole responses and possessing several features in the near infrared range. Using the polarizability spectra of single nanoparticles and applying the tuning strategy, the design of the MoS2_2 metasurface supporting three resonances of quasi-trapped modes at once in a narrow spectral range was developed. One of these resonances corresponds to the telecom wavelength of 1550 nm. The spectrum of light reflection for MoS2_2 metasurface is characterized by three narrowband dips corresponding to the wavelengths of the quasi-trapped modes. It was shown that a change in the polarization of a wave normally incident on the metasurface to orthogonal one leads to a change in the type of bianisotropic response excited in each MoS2_2 disk and to the excitation of three other features in the reflection spectra of the metasurface at wavelengths close to the initial values.Comment: 8 pages, 5 figure
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