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[IEEE 2019 IEEE Conference on Antenna Measurements & Applications (CAMA) - Kuta, Bali, Indonesia (2019.10.23-2019.10.25)] 2019 IEEE Conference on Antenna Measurements & Applications (CAMA) - Receiving Performance of Antenna-Coupled Electrode Electro-Optic Modulators for 5G Frequency Band
摘要： We have already proposed and developed an antenna-coupled- electrode electro-optic (EO) modulator for 28 GHz-band 5th generation mobile communication as a receiving antenna. The designed EO modulator was fabricated a metal ground plane backed linear dipole array using a 50-μm-thick LiNbO3 crystal and a 250-μm-thick SiO2 base. In this paper, we have shown antenna receiving patterns for 1-element dipole antenna, 4-element dipole array antenna and 8-elemen dipole array antenna. Half power beam width for H-plane of our developed receiving antennas are 70, 25 and 11 degree for 1 element, 4-element and 8-element dipole array, respectively.
关键词： 5G mobile communication,radio over fiber,LiNbO3,optical modulator,receiving antenna,ground plane backed dipole array
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Nanoprobe-Enabled Electron Beam Induced Current Measurements on III-V Nanowire-Based Solar Cells
摘要： The development of two new types of high-density, electroless plated microelectrode arrays for CMOS-based high-sensitivity direct bacteria and HeLa cell counting are presented. For emerging high-sensitivity direct pathogen counting, two technical challenges must be addressed. One is the formation of a bacteria-sized microelectrode, and the other is the development of a high-sensitivity and high-speed amperometry circuit. The requirement for microelectrode formation is that the gold microelectrodes are required to be as small as the target cell. By improving a self-aligned electroless plating technique, the dimensions of the microelectrodes on a CMOS sensor chip in this work were successfully reduced to 1.2 μm × 2.05 μm. This is 1/20th of the smallest size reported in the literature. Since a bacteria-sized microelectrode has a severe limitation on the current flow, the amperometry circuit has to have a high sensitivity and high speed with low noise. In this work, a current buffer was inserted to mitigate the potential fluctuation. Three test chips were fabricated using a 0.6-μm CMOS process: two with 1.2 μm × 2.05 μm 1024 × 1024 and 4 μm × 4 μm (16 × 16) sensor arrays and one with 6-μm × 6-μm (16 × 16) sensor arrays; and the microelectrodes were formed on them using electroless plating. The uniformity among the 1024 × 1024 electrodes arranged with a pitch of 3.6 μm × 4.45 μm was optically verified. For improving sensitivity, the trenches on each microelectrode were developed and verified optically and electrochemically for the first time. Higher sensitivity can be achieved by introducing a trench structure than by using a conventional microelectrode formed by contact photolithography. Cyclic voltammetry (CV) measurements obtained using the 1.2 μm × 2.05 μm 16 × 16 and 6-μm × 6-μm 16 × 16 sensor arrays with electroless-plated microelectrodes successfully demonstrated direct counting of the bacteria-sized microbeads and HeLa cells.
关键词： Bacteria counting,HeLa cells,electroless plating,point-of-care testing,CMOS,microelectrode array
更新于2025-09-23 15:19:57
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[IEEE 2019 34th Symposium on Microelectronics Technology and Devices (SBMicro) - Sao Paulo, Brazil (2019.8.26-2019.8.30)] 2019 34th Symposium on Microelectronics Technology and Devices (SBMicro) - Effect of the dopant location and the number of Bragg mirrors on the performance of superlattice infrared photodetectors
摘要： This paper presents a substrate integrated waveguide Butler matrix with a modi?ed hybrid coupler, operating from 28 to 32 GHz. The modi?ed hybrid coupler is realized by using 90? hybrid coupler followed by a ?45? compensating phase shifter. Thus, 45?/135? output phase differences can be obtained using this type of coupler. Compared with the equal-length unequal-width phase shifter, the compensating phase shifter exhibits better phase characteristics, with only 3? phase error over 28–32 GHz. Because the phase of compensating phase shifter is not realized by taking the phase introduced by the crossover as a reference, it gives great ?exibility to the design of compensating phase shifter. Adopting the modi?ed hybrid coupler, the designed Butler matrix features the output phases with peak to peak error of 13? and wideband performance from 28 to 32 GHz. The slot array fed by the Butler matrix can radiate four slanted beams with acceptable measured gains, in the range of 9.7～12 dBi for port 1 excitation and 8.4～11.1 dBi for port 2 excitation. The radiated beams can reach a wide azimuthal coverage between ±61?.
关键词： Butler matrix,Modi?ed hybrid coupler,substrate integrated waveguide (SIW),compensating phase shifter,slot array antenna
更新于2025-09-23 15:19:57
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Organic Printed Core-Shell Heterostructure Arrays: A Universal Approach to All-Color Laser Display Panels
摘要： We demonstrate a universal approach for realizing dual-wavelength lasing in organic core-shell structured microlaser arrays, which show great promise in serving as all-color laser display panels. By alternately printing hydrophilic and hydrophobic laser dye solutions on preprocessed substrates, we successfully obtained precisely patterned core-shell heterostructure arrays. The spatially-separated core and shell independently function as optical resonators to support dual-wavelength tunable microlasers in each heterostructure. Such a general method enables to flexibly control the lasing wavelength of the core-shell microlasers across a wide spectral range by systematically designing the gain media. Using as-prepared microlaser arrays as display panels, we achieved full-color laser displays, representing an achievable color gamut much larger than that of standard RGB space. These results may provide new insights for design concepts and device construction for novel optoelectronic applications.
关键词： laser display,organic heterostructure,core-shell structure,dual-wavelength laser,laser array
更新于2025-09-23 15:19:57
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Investigation of modulation transfer function in InGaAs photodetector small pitch array based on three-dimensional numerical analysis
摘要： Three-dimensional numerical simulation technology was used to investigate the influence of structural and material parameters on the modulation transfer function (MTF) of lattice matched InGaAs/InP planar small pitch arrays. We found that extending depletion zone through increasing depth of diffusion junction and reducing the doping concentration in the absorption layer plays a critical role in optimizing the MTF of arrays. And it is highly worth noting that the very optimization effects become even more pronounced in smaller pitch arrays, which offers valuable references to restrain crosstalk in highly dense array and strengthen the imaging ability of large format photodetector system in future. However, the inevitable cost of deteriorating the specific detectivity should not be ignored. And hence, junction depth and doping concentration of the absorption layer need to be balanced in actual preparation. In addition, the effects of lattice temperature on MTF and crosstalk in arrays were also discussed. The inter-pixel crosstalk deteriorates seriously as rising lattice temperature. A stronger impact of lattice temperature on MTF of larger pitch arrays has been confirmed. This work offers important reference to suppress inter-pixel crosstalk in obtaining the high-resolution imaging for InGaAs photodetector focal plane array.
关键词： InGaAs photodetector array,Three-dimensional numerical analysis,Modulation transfer function,Crosstalk
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Adaptive Decision-making for Robotic tasks
摘要： Hannan introduced in 1964 an embedded element efficiency concept that explains the so-called element-gain paradox in antenna arrays, i.e., that the array gain always is smaller than the sum of the element gains. In the present letter, we show for the first time the usefulness of his approach by evaluating directivities and aperture efficiencies of an array of open-ended waveguides by commercial full-wave electromagnetic (EM) solvers for a large range of element spacing. The results show also that by using embedded element analysis, the realized gain of regular arrays actually becomes equal to the sum of the realized gains of the embedded elements. Thus, the embedded element efficiency is more practical to use in design and numerical analysis than the more commonly used active element pattern approach. We also show that the embedded element efficiency can be approximated by a simple formula when the element spacing is smaller than half-wavelength.
关键词： fundamental limitations,embedded element efficiency,Array antenna
更新于2025-09-23 15:19:57
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Tunable Plasmonic Resonances in TiN Nanorod Arrays
摘要： In this work, titanium nitride (TiN) nanorod arrays were fabricated using glancing angle deposition in a magnetron sputtering system. The deposition parameters, including the bias on the substrate and the flow rate of nitrogen, were varied to deposit various TiN nanorod arrays. Before glancing angle deposition was conducted, uniform TiN films were deposited and their permittivity spectra, for various deposition parameters, were obtained. The effect of the deposition parameters on the morphology of the nanorods is analyzed here. The polarization-dependent extinctance spectra of TiN nanorod arrays were measured and compared. Extinction, which corresponds to the longitudinal mode of localized surface plasmon resonance, can be significantly changed by tuning the N2 flow rate and substrate bias voltage during deposition.
关键词： glancing angle deposition,plasmonic mode,permittivity,titanium nitride,nanorod array
更新于2025-09-23 15:19:57
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Magnetic Layer-by-Layer Assembly: From Linear Plasmonic Polymers to Oligomers
摘要： One-dimensional (1D) nanostructures with controllable aspect ratios are essential for a wide range of applications. An approach for magnetic superparticle (SP) assembly over large areas (55 mm × 25 mm) is introduced via co-assistance of electrostatic and magnetic fields, so-called magnetic layer-by-layer (MLBL) assembly, on an arbitrary hydrophilic substrate within minutes. The SP structures (diameter (d.) = 120-350 nm) of Fe3O4 or Ag@Fe3O4 composites composed of hundreds of magnetite nanocrystals (d. 10–20 nm) are used as colloidal monomers to fabricate arrays of high-aspect-ratio (up to 102) linear nanochains, viz. colloidal polymers, where thermal disturbances were minimized. The arrays of colloidal polymers exhibit strong optical polarization effects owing to their geometrical anisotropy, which can be used as a simple optical filter. Furthermore, by using the binary colloidal mixture of different magnetic colloids including different-sized Fe3O4 and magnetoplasmonic Ag@Fe3O4, low-aspect-ratio (2~15) colloidal chains, viz. magnetic/plasmonic oligomers, with tunable lengths were fabricated, affording a facile but effective approach to modulate the optical properties of the chains. The scalable fabrication of well-aligned, linear colloidal polymers and oligomers opens up appealing opportunities for the development of sensors, sub-wavelength waveguides, optical tweezers, and enhanced solar harvesting devices.
关键词： nanochain array,layer-by-layer,linear nanochain,colloidal oligomer,plasmonic oligomer,magnetic field induced assembly
更新于2025-09-23 15:19:57
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The transparent device of CdS quantum dots modified Cu2O/ZnO orderly nano array p-n junction towards the enhanced photovoltaic conversion
摘要： The transparent device of CdS QDs modified Cu2O/ZnO nano array p-n junction is prepared via simple continuous magnetron sputtering method and chemical deposition. The p-n junction device with good stability exhibits decent transparency of about ~80% in visible light, and evident photovoltaic response enhancement of about ~100 times than the unmodified sample, that can be mainly attributed to the CdS QDs with high QY can improve the visible light response, the p-n junction with self-photovoltage and the ZnO order arrays can improve the transport of the photon-generated carriers.
关键词： p-n junction,CdS quantum dots,Orderly nano array,Transparent device
更新于2025-09-23 15:19:57
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DUAL-BAND CIRCULAR POLARIZED SLOT ARRAY ANTENNA IN SUBSTRATE INTEGRATED WAVEGUIDE USING TWO PROPAGATION MODES FOR COMMUNICATION SATELLITES TRANSCEIVERS
摘要： A novel dual-band circularly-polarized slot array antenna aimed at LEO satellites communications where up-link and down-link operate at di?erent frequencies is introduced. By using higher order modes, the slots can be placed at points where current distributions are null for the fundamental mode. According to this idea, at the receiver frequency band the slots are placed to be excited by mode T E10 currents distribution, and at the transmitting band slots are forced to radiate according to mode T E20 currents distribution. A matching load termination is used to generate the required travelling wave to obtain the circular polarization, introducing low dissipation losses. Additionally, in this investigation an antenna feeder is also designed. Both the feeder and the slot antenna array are designed using Substrate Integrated Waveguide (SIW). The use of SIW makes easier the design of the transitions from the array to the microstrip input lines and the grounded-coplanar termination as well, relaxing fabrication constraints and tolerance.
关键词： dual-band,Substrate Integrated Waveguide,slot array antenna,circularly-polarized,communication satellites transceivers
更新于2025-09-23 15:19:57