A5101405700- Advanced Antenna and Metasurface Technologies
- Antenna Design and Analysis
- Metamaterials and Metasurfaces Applications
- Microwave Engineering and Waveguides
- Atomic and Molecular Physics
- Antenna Design and Optimization
- Semiconductor Quantum Structures and Devices
- Cold Atom Physics and Bose-Einstein Condensates
- Photonic and Optical Devices
- Semiconductor materials and interfaces
- Chalcogenide Semiconductor Thin Films
- Quantum, superfluid, helium dynamics
- Particle accelerators and beam dynamics
- Optical and Acousto-Optic Technologies
- Graphene research and applications
- Orbital Angular Momentum in Optics
- Ion-surface interactions and analysis
- Particle Accelerators and Free-Electron Lasers
- Microfluidic and Bio-sensing Technologies
- Laser-induced spectroscopy and plasma
- Laser-Plasma Interactions and Diagnostics
- Mass Spectrometry Techniques and Applications
- Radio Frequency Integrated Circuit Design
- GaN-based semiconductor devices and materials
- Advancements in PLL and VCO Technologies
China Electronics Technology Group Corporation
2023-2024
University of Electronic Science and Technology of China
2016-2021
Brookhaven National Laboratory
2014
University of Puerto Rico System
2006-2008
Donghua University
2003-2008
The University of Sydney
2001-2002
La Trobe University
1999-2001
A wideband linearly polarized transmitarray antenna operating in 7-16 GHz is presented this paper. First, a element with three metallic layers proposed, which composed of split circular ring connected by narrow strip the middle layer, and two polarizers upper bottom layers. This features low transmission loss approximately linear phase curves wide frequency band over one octave. Then, an optimization method introduced to design that follows bandwidth definition 1 dB gain drop. The first key...
Combining the advantages of lens antenna and array techniques, transmitarrays have been widespreadly concerned in recent years. In first part this paper, a wideband four-layer transmitarray operating at 13 GHz fed by horn with focus-to-diameter ratio (F/D) unity is proposed. The employed elements composed dual-resonance double hexagonal rings are closely arranged honeycomb lattice. simulated results show that can achieve 53.34% peak aperture efficiency 19.23% bandwidth for 1 dB gain drop,...
A transmitarray antenna (TAA) fed by a phased array (PAA) for one-dimensional (I-D) beam scanning is proposed at 10 GHz in this letter. The TAA composed of two types elements, i.e., the hexagonal subwavelength low-pass elements as well pure dielectric ones. PAA feed I-D printed dipole loaded with short-circuited dummy PAA-fed TAA, feeding-distance-to-TAA-diameter ratio (HID) mere 0.375, achieves peak simulated gain 25.6 dBi 0° (corresponding to aperture efficiency 57.5%) and 3.13 dB drop...
A transmitarray antenna (TAA) with a small-scale circular phased array (PAA) feed is proposed in this article to generate orbital angular momentum (OAM)-carrying radio beams. After analyzing the operating mechanisms of OAM-generating PAA-fed TAA, its numerical model further developed determine TAA element arrangement and PAA excitation coefficients. Furthermore, three-layer polarization-conversion property traditional patch are identified as elements feed, respectively. Benefiting from...
Combining the inherent multiple beam capabilities of transmitarray antennas (TAAs) and flexible fields launched by phased array (PAAs), PAA-fed TAAs are proposed in this paper for high-gain wide-angle scanning millimeter-wave (MMW) band. After thoroughly analyzing operating mechanisms TAAs, a divisionally multi-focal method is to deploy TAA elements, which can be better adapted PAA feed whereby performances improved. Subsequently, two with feeding distance-to-diameter ratios (H/Ds) mere 0.28...
A filtering transmitarray antenna (TAA) with high-gain in-band radiations at the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$X$ </tex-math></inline-formula> -band and an out-of-band low-scattering characteristic is presented in this communication. The proposed composite TAA element consists of a dual-polarized resistive sheet, fixed bandstop frequency-selective surface (FSS) element, adjustable...
A transmitarray antenna (TAA) with a small-scale phased array (PAA) feed is proposed in this communication. After modeling the PAA-fed TAAs and constructing cost functions, threestep optimization process introduced to determine TAA element arrangement as well PAA excitation coefficients. Then, novel ultrawideband proposed, which has pair of connected sheep-horn metallic patterns middle layer sandwiched by two orthogonal grid polarizers on upper bottom layers. Furthermore, traditional Vivaldi...
In this paper, a defocused cylindrical Luneburg lens antenna with phased array (PAA) feed operating at 10 GHz is proposed. After equivalent and defocusing procedures, developed, effectively dispersing the energy over focal area. Furthermore, 19-element dipole PAA, which has been partitioned into three linear subarrays, illuminates weighted excitation coefficients optimized by introduced active element-lens pattern (AELP) method. Comprehensive analyses of AELP method classical conjugate field...
This article presents a design concept of integrative transmitarray antenna (TAA) with gain-filtering and low-scattering characteristics. The TAA element combines bandpass frequency-selective surface (FSS) square dielectric post antireflection pyramidal structures (SDPP), achieving the simultaneous control in-band transmitted waves out-of-band reflected waves. FSS provides phase-shifting capabilities around center operating frequency <inline-formula...
The production of helium 2 1S singlet metastable atoms has been investigated using a hollow cathode discharge and Penning discharge, under dc conditions. density was measured by atomic absorption the 1S–3 1P transition (501.57 nm). A range plasma currents, varying from 16 to 180 mA, pressures, 100 mTorr 5 Torr, were investigated. This work is directed ultimately supersonic beam for diagnostics, in particular measurement electric fields laser induced fluorescence.
A high density of metastable helium atoms has been created using a Penning-type discharge. Experimental data indicate that the increases with increase in gas pressures range from 0.1 mTorr to 0.5 Torr. The highest 3.5×1016 m−3 is observed at steady-state pressure relationships between densities and plasma discharge current are also obtained.
One-dimensional tilted carbon nanorod arrays were synthesized on molybdenum substrates by using the catalyst-assisted oblique angle deposition technique. The structures of one-dimensional nanorods evolve with substrate temperatures, but otherwise identical growth conditions. crystallographic structures, chemical compositions and bond investigated x-ray diffraction, energy dispersive spectroscopy, photoelectron spectroscopy Raman scattering spectroscopy. cross-sectional SEM image showed that...
MBE growth of MgSe thin films on ZnSe/GaAs(001) substrates is studied. Insight into the formation mechanism this type surface, interface, and bulk has been provided by photoemission spectroscopy. Detailed lineshape analyses Se, Mg, Zn core levels have performed, following their evolution as deposited. Shifts for all are very small during deposition, indicating band bending virtually negligible under present conditions. After deposition 1.7 nm MgSe, emission from substrate fully attenuated. A...
A new Penning type of discharge has been used to generate high-density metastables. The highest metastable density 3.5 × 1016 m−3 is obtained at a static gas pressure 500 mTorr. At 0.5 mTorr discharge, we achieve very high abundance metastables N(21S)/N(He) up 10−3. These densities are enough be in diagnosing the internal electric field inside plasma source based on laser-induced fluorescence techniques.
The high profile of the space-fed antennas is main restriction for practical applications. Traditional design method to pursue compactness this kind antenna decrease focus-to-diameter ratio (F/D), but suffers from performance degradation. To address issue, a small dipole array chosen as feed in our design. By employing conjugate field matching (CFM) technology, can effectively excite transmitarray with significant reduction profile. Compared an identical excited by traditional horn, although...
A phased transmitarray antenna (TAA) is proposed at 28 GHz for the fifth-generation (5G) base station applications in this paper. The TAA composed of subwavelength low-pass elements, featuring an aperture area 130 × mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Meanwhile, a 4×4-element array (PAA) employed to illuminate TAA. By elaborately deploying excitation phases PAA feed, PAA-fed achieves high-gain beam scannings always with...
A supersonic He beam source, which consists of a commercial pulse generator and pulsed nozzle with diameter 0.8 mm, is fabricated. The helium ejected from nozzle, then collimated through skimmer. We observe that the density inversely proportional to square distance. At longitudinal position Y = 12 cm away atom densities beams 8.4 × 1014 cm−3 (26 mTorr) 6.1 (19 are obtained for backing pressure 101 kPa gaps between skimmer D 1 3 mm. Experimental data indicate radial width around 64 mm at 19...