Test results of high-voltage one- and four-channel radio-frequency (RF) generators based on the coaxial gyromagnetic ferrite-filled nonlinear transmission lines (NLTL) with external magnetic bias and RF-modulation frequency of a high-voltage pulse envelope of ∼8 GHz are presented. Electrical strength of oil-isolated NLTLs was tested in a compact version of one-channel generator based on the RADAN driver at a repetition rate of 100 pps. In case of a stationary setup, 5-ns pulse with -500 kV amplitude was split into 4 channels with individual NLTLs. Gyromagnetic line output pulses had fast damped RF-modulation with a maximum modulation depth more than 50% and the peak amplitude of -200 kV. Independent control of a delay time in each channel was realized by the coaxial spiral lines with a central biased ferrite core. The coherent summation possibility of RF fields in the free space radiated by a 4-channel system of conical dielectric antennas was demonstrated.
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http://dx.doi.org/10.1063/1.5091075 | DOI Listing |
Nano Lett
January 2025
Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
The complete manipulation of Jones matrix phase-channels using metasurfaces brings forth unparalleled possibilities across diverse wavefront modulation applications. Traditionally, achieving independent control over all four phase-channels usually involves the introduction of chirality with multilayer or three-dimensional metasurfaces. Here, we present a general chirality-free method that relies on polarization base transformation with a planar minimalist metasurface, effectively decoupling the four Jones matrix phase-channels, thereby unleashing the fundamental boundaries imposed by conventional linear or circular polarization bases.
View Article and Find Full Text PDFNanophotonics
August 2024
Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China.
Front Aging Neurosci
November 2024
Department of Neurological Rehabilitation, Jiangbin Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.
Background: Mild cognitive impairment (MCI) is generally considered to have a high risk of progression to Alzheimer's disease. Our study aimed to investigate the abnormal functional connectivity (FC) in prefrontal cortex (PFC) in patients with MCI and explore the relationship between the observed changes and cognitive function.
Methods: Sixty-seven patients with MCI and 71 healthy individuals were recruited for this study.
Plant J
November 2024
College of Electronic Information and Physics, Central South University of Forestry and Technology, Changsha, 41004, Hunan, China.
We designed a multi-channel comb filter generation scheme with nearly consistent channel numbers and free spectral range (FSR) in standard 220-nm-thick silicon-on-insulator (SOI) technology. This scheme relies on the formation of optical microcavities using Bragg grating structures, which serve as reflectors. By precisely designing the optical path length of the microcavity, we can generate optical filters with a specific number of channels.
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