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Modeling of the Marine atmosphere and its impact on Ka-band channels [PDF]

open access: yesMATEC Web of Conferences, 2022
The sea atmosphere environment will affect the Ka frequency channel in TT&C. Firstly, this paper briefly introduces the Marine atmospheric environment. Attenuation models of water vapor solubility and rainfall intensity are established.
Liu Zheng, Sun Fu-an, Zhou Bin
doaj   +1 more source

Research on the phase-frequency relationship of the field effect amplifier front-end of shipborne USB system [PDF]

open access: yesMATEC Web of Conferences, 2022
Normally, most researches on phase calibration of shipborne USB system focus on the means of phase calibration. This article starts with the research on the channel of the system.
Sun Fuan, Liu Zheng, Liu Huifeng
doaj   +1 more source

A Review of Multibeam Phased Array Antennas as LEO Satellite Constellation Ground Station

open access: yesIEEE Access, 2021
Small satellites in low Earth orbit (LEO) are typically organized as a satellite constellation. The satellite number of a LEO satellite constellation would be several hundred or even tens of thousands to realize a fully global coverage.
Guolong He   +3 more
doaj   +1 more source

The adaptive neural network fuzzy sliding mode control for the 3-RRS parallel manipulator

open access: yesAdvances in Mechanical Engineering, 2022
In order to improve the high-precision tracking control of angle variables and the sliding mode equivalent control part for the 3-RRS parallel manipulator, an adaptive neural network fuzzy sliding mode control algorithm with self-adjusting switching gain
Xiyu Li   +7 more
doaj   +1 more source

Impact Analysis and Calibration Methods of Excitation Errors for Phased Array Antennas

open access: yesIEEE Access, 2021
Phased array antennas have played a very important role in many different areas and applications. It requires precise excitation of each antenna element by various synthesis techniques to obtain desired array pattern features.
Guolong He, Xin Gao, Rentian Zhang
doaj   +1 more source

Digital resignation and the datafied welfare state

open access: yesBig Data & Society, 2023
This commentary calls for further research into digital resignation within non-market contexts, particularly in relation to the datafied welfare state, as distinct from commercial big tech platforms. We aim to nuance the concept of digital resignation by
Christoffer Bagger   +4 more
doaj   +1 more source

Optical Phased Array-Based Laser Beam Array Subdivide Pixel Method for Improving Three-Dimensional Imaging Resolution

open access: yesPhotonics, 2023
The small number of pixels in the current linear mode avalanche photodiode (LM-APD) array limits its three-dimensional (3D) imaging resolution. We use an optical phased array-based beam array subdivided pixel method to improve the 3D imaging resolution ...
Shuai Wang   +7 more
doaj   +1 more source

Miniaturized Dual-Band Bandpass Filter With Sharp Roll-Off Using Ring-Loaded Resonator

open access: yesIEEE Access, 2020
In this paper, a miniaturized dual-band bandpass filter (BPF) with good selectivity based on ring-loaded resonator (RLR) and 0° feed structure is proposed.
Daotong Li   +3 more
doaj   +1 more source

Multi-Scenario Trajectory Optimization for Vertical Takeoff and Vertical Landing Vehicles Using the Gauss Pseudospectral Method

open access: yesAerospace, 2022
Vertical takeoff and vertical landing (VTVL) vehicles, based on throttling liquid rocket engines, are attracting increasing attention for their validation of guidance and control techniques during landing.
Yang Liu   +5 more
doaj   +1 more source

Advances of SBAS authentication technologies

open access: yesSatellite Navigation, 2021
Satellite Based Augmentation System (SBAS) provides the corrections and integrity information to users, but as its signal format is opened to the public and Global Navigation Satellite System (GNSS) spoofing technology becomes more realistic, more ...
Ying Chen   +8 more
doaj   +1 more source

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