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A D-band Multiplier-based OOK Transceiver with Supplementary Transistor Modeling in 65-nm Bulk CMOS Technology
摘要： A D-band on-off keying (OOK) transceiver chipset is fabricated in a 65-nm bulk CMOS technology as a low-cost and highly-integrative solution to short-distance wireless connectivity. Supplementary transistor modeling is performed for accurate circuit design at mm-wave frequencies. To overcome low transistor fmax and reduce DC power consumption, the transmitter employs a frequency-multiplier-based architecture with no power amplifier. The receiver adopts a non-coherent architecture consisting of a DC-coupled three-stage differential amplifier and an envelope detector. The OOK transmitter exhibits a measured output power of -9.8 dBm and on-off level difference of 13.2 dB at 134.1 GHz. The receiver shows a measured average responsivity of 4.1 kV/W and a noise equivalent power of 211.4 pW/Hz1/2 over all D-band frequencies. The DC power consumption of the transmitter and receiver are 76 mW and 32.5 mW, respectively. The transceiver is tested in both on-chip loopback and air-channel configurations, and demonstrates data transmission up to 10 Gbps and 2 Gbps at a distance of 0.03 m, respectively.
关键词： transceiver,transistor modeling,D-band,wireless communication,low-cost bulk CMOS,OOK
更新于2025-09-23 15:22:29
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[IEEE 2019 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) - Auckland, New Zealand (2019.5.20-2019.5.23)] 2019 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) - Waveguide Joint Design and Validation for use in Acoustic Vector-corrected Network Analysers
摘要： Cameras embedded in consumer devices have previously been used as physiological information sensors. The waveform of the photoplethysmographic image (PPGi) signals may be significantly affected by the light spectra and intensity. The purpose of this paper is to evaluate the performance of PPGi waveform acquisition in the red, green, and blue channels using a commercial camera in different light conditions. The system, developed for this paper, comprises of a commercial camera and light sources with varied spectra and intensities. Signals were acquired from the fingertips of 12 healthy subjects. Extensive experiments, using different wavelength lights and white light with variation light intensities, respectively, reported in this paper, showed that almost all light spectra can acquire acceptable pulse rates, but only 470-, 490-, 505-, 590-, 600-, 610-, 625-, and 660-nm wavelength lights showed better performance in PPGi waveform compared with gold standard. With lower light intensity, the light spectra >600 nm still showed better performance. The change in pulse amplitude (ac) and dc amplitude was also investigated with the different light intensity and light spectra. With increasing light intensity, the dc amplitude increased, whereas ac component showed an initial increase followed by a decrease. Most of the subjects achieved their maximum averaging ac output when averaging dc output was in the range from 180 to 220 pixel values (8 b, 255 maximum pixel value). The results suggested that an adaptive solution could be developed to optimize the design of PPGi-based physiological signal acquisition devices in different light conditions.
关键词： low-cost camera,light spectrum,light intensity,Photoplethysmographic image
更新于2025-09-23 15:21:01
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Graphene Quantum Dots with High Yield and High Quality Synthesized from Low Cost Precursor of Aphanitic Graphite
摘要： It is di?cult to keep the balance of high quality and high yield for graphene quantum dots (GQDs). Because the quality is uncontrollable during cutting large 2D nanosheets to small 0D nanodots by top-down methods and the yield is low for GQDs with high quality obtained from bottom-up strategy. Here, aphanitic graphite (AG), a low-cost graphite contains a large amount of small graphite nanocrystals with size of about 10 nm is used as the precursor of graphene oxide quantum dots (GO-QDs) for the ?rst time. GO-QDs with high yield and high quality were successfully obtained directly by liquid phase exfoliating AG without high strength cutting. The yield of these GO-QDs can reach up to 40 wt. %, much higher than that obtained from ?ake graphite (FG) precursor (less than 10 wt. %). The size of GO-QDs can be controlled in 2–10 nm. The average thickness of GO-QDs is about 3 nm, less than 3 layer of graphene sheet. Graphene quantum dots (GQDs) with di?erent surface properties can be easily obtained by simple hydrothermal treatment of GO-QDs, which can be used as highly e?cient ?uorescent probe. Developing AG as precursor for GQDs o?ers a way to produce GQDs in a low-cost, highly e?ective and scalable manner.
关键词： high yield,high quality,low cost precursor,aphanitic graphite,graphene quantum dots
更新于2025-09-23 15:21:01
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Facile synthesis of a??lucky clovera?? hole-transport material for efficient and stable large-area perovskite solar cells
摘要： Hole-transporting materials (HTMs) play a vital role of transporting holes from the perovskite layer to the counter electrode in perovskite solar cells (PSCs). A novel HTM BTPA-8 is feasibly synthesized by incorporating four dimethoxytriphenylamine leaflets and anthracene-based central bridge. BTPA-8 exhibits a suitable band alignment with MAPbI3 (MA ? CH3NH3) or FA0.85MA0.15PbI3 (FA?HC(NH2)2), high hole mobility, and high thermal stability. The best FA0.85MA0.15PbI3 device based on BTPA-8 exhibits a power conversion efficiency (PCE) of 17.99% in the reverse scan with an aperture area of 0.09 cm2. Under the same condition, a PCE of 18.92% is achieved by the solar cell based on the standard spiro-OMeTAD (2,2,7,7-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9-spirobifluorene). A comparable PCE of 12.31% is also obtained for BTPA-8 based MAPbI3 device compared with spiro-OMeTAD (13.25%) with an aperture area >1 cm2. BTPA-8 based PSCs exhibit better long-term stability than spiro-OMeTAD due to its high hydrophobicity. A lower synthesis cost of BTPA-8 than that of spiro-OMeTAD along with the elevated long-term stability makes it promising for application in PSCs.
关键词： Perovskite solar cells,Hole-transporting material,Anthracene,Low cost
更新于2025-09-23 15:21:01
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Ternary copolymerization strategy reducing the cost of benzodithiophenea??benzodithiophenedione polymer, retaining high photovoltaic performance
摘要： The photovoltaic performance of organic solar cells has been rapidly improved. However, in actual production and application, there are still many challenges for organic photovoltaic devices and one of the important strategies to facilitate industrialization is reducing material price. The BDT-BDD binary copolymer donor material has good photovoltaic performance. However, the high price of benzodithiophenedione (BDD) monomer limits its industrialization. In contrast, benzotriazole (BTA) monomers with lower price possess an enormous potential to solve this problem. Therefore, in this paper, it is reported that the synthesis of ternary copolymerization by adding BTA units into BDT-BDD copolymer with two different acceptor units. Through research, it is found that such a strategy can effectively reduce the price of BDT-BDD polymer, and increasing the content of BTA units in polymer to reduce the content of expensive BDD units can still retain the excellent photovoltaic properties of BDT-BDD polymer. When only 20 mol % of BDD units remained, the bulk-heterojunction (BHJ) structure with the synthesized donor polymer and acceptor ITIC can achieve an open circuit voltage of 0.913 V with a short circuit current of 16.87 mA cm-2 and 9.12% maximum photoelectric conversion efficiency, which is much cheaper than BDT-BDD polymer, in terms of structural units. Therefore, the results show that the addition of BTA can effectively reduce the material cost (vs. BDD only) while retaining the good photovoltaic properties of the material, and has a certain guiding effect on the commercialization of OSC.
关键词： electron donor materials,ternary copolymer,optical properties,low-cost donor materials
更新于2025-09-23 15:21:01
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Nona??Conjugated Polymer Based on Polyethylene Backbone as Dopanta??Free Holea??Transporting Material for Efficient and Stable Inverted Quasia??2D Perovskite Solar Cells
摘要： Novel non-conjugated polymer based on polyethylene backbone, PVCz-OMeTPA with suitable energy levels, good hole mobility as well as excellent film-forming ability assisting the formation of high-quality perovskite films, is developed as efficient dopant-free hole-transporting materials (HTMs) for inverted quasi-2D perovskite solar cells (PSCs). Quasi-2D PSCs using ultra-thin, dopant-free PVCz-OMeTPA as HTM exhibited excellent power conversion efficiency of 17.22% and long-term environmental stability.
关键词： low-cost,quasi-2D perovskite solar cells,main-chain non-conjugated polymer,dopant-free hole-transporting materials
更新于2025-09-23 15:21:01
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Cost analysis of solar thermal propulsion systems for microsatellite applications
摘要： In recent years, satellite design has extended towards miniaturisation to reduce associated cost with launching and conducting space missions. Small satellites provide low-cost platforms for space missions. However, this lower cost comes at the expense of the removal of key sub-systems, such as the propulsion system, due to the small available onboard volume and mass restrictions. For this reason, small, lightweight, high-performing and affordable propulsion systems are necessary. However, there is limited research available on the comparison of propulsion technologies with regards to cost. Motivated by the above challenges the objective of this paper is to provide a comparison of propulsion technologies that are compatible with small satellites with respect to cost and application. The different propulsion systems are investigated for three mission scenarios, a small on-orbit manoeuvre, a station-keeping, and a lunar orbit transfer mission. Each system is evaluated in terms of a total figure of merit which incorporates nine variables such as propellant mass, safety, and hardware price, that affect the total cost of a propulsion system. This figure of merit is used to quantitatively compare the propulsion systems to identify cost-effective solutions as a function of various mission scenarios. Solar thermal propulsion has been proposed for small satellite applications, but information regarding the concepts are not available in a single report. Therefore, another objective of this paper is to provide the reader with a review of the current status of solar thermal propulsion. An important finding of this research is the classification of propulsion systems in terms of thrust, specific impulse, cost, and application.
关键词： Solar Thermal Propulsion,Low-cost Propulsion Systems,Small Satellites
更新于2025-09-23 15:21:01
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[IEEE 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Daejeon, Korea (South) (2019.7.28-2019.8.1)] 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Wavelength-selective beam deflector based on Fano-resonant metasurface
摘要： Cameras embedded in consumer devices have previously been used as physiological information sensors. The waveform of the photoplethysmographic image (PPGi) signals may be significantly affected by the light spectra and intensity. The purpose of this paper is to evaluate the performance of PPGi waveform acquisition in the red, green, and blue channels using a commercial camera in different light conditions. The system, developed for this paper, comprises of a commercial camera and light sources with varied spectra and intensities. Signals were acquired from the fingertips of 12 healthy subjects. Extensive experiments, using different wavelength lights and white light with variation light intensities, respectively, reported in this paper, showed that almost all light spectra can acquire acceptable pulse rates, but only 470-, 490-, 505-, 590-, 600-, 610-, 625-, and 660-nm wavelength lights showed better performance in PPGi waveform compared with gold standard. With lower light intensity, the light spectra >600 nm still showed better performance. The change in pulse amplitude (ac) and dc amplitude was also investigated with the different light intensity and light spectra. With increasing light intensity, the dc amplitude increased, whereas ac component showed an initial increase followed by a decrease. Most of the subjects achieved their maximum averaging ac output when averaging dc output was in the range from 180 to 220 pixel values (8 b, 255 maximum pixel value). The results suggested that an adaptive solution could be developed to optimize the design of PPGi-based physiological signal acquisition devices in different light conditions.
关键词： Photoplethysmographic image,light intensity,light spectrum,low-cost camera
更新于2025-09-23 15:19:57
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Laser speckle reduction utilized by lens vibration for laser projection applications
摘要： In this paper, a compact speckle reduction method utilizing vibrating lenses for laser beam scanning is proposed and demonstrated. The maximum speckle reduction ef?ciency was found to be 75.6% and 81.25% for a 532 nm diode-pumped solid-state (DPSS) laser and a 520 nm laser diode (LD), respectively. The minimum speckle contrast ratio observed using our method was 0.11 for the DPSS laser and 0.06 for the LD. The proposed method can provide speckle reduction with minimal power requirements, a low implementation cost, and no bending for the optical path of the laser beam. Additionally, this method is promising to withstand high-power lasers for use in high lumen laser projectors by optimizing the lens parameters. The demonstrated technique has a small form factor while simultaneously demonstrating a high degree of speckle reduction, which shows potential for speckle reduction in mini- and pico- laser projector applications.
关键词： pico-projectors,compact method,laser displays,vibrating lens,speckle reduction,mini-projectors,low cost
更新于2025-09-23 15:19:57
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High-performance plasmonic refractive index sensors via synergy between annealed nanoparticles and thin films
摘要： Plasmonic nanostructure-based refractive index (RI) sensors are the core component of biosensor systems and play an increasingly important role in the diagnosis of human disease. However, the costs of traditional plasmonic RI sensors are not acceptable to everyone due to their expensive fabrication process. Here, a novel low-cost and high-performance visible-light RI sensor with a particle-on-film configuration was experimentally demonstrated. The sensor was fabricated by transferring annealed Au nanoparticles (NPs) onto a thin gold film with polymethyl methacrylate (PMMA) as a support. RI sensitivities of approximately 209 nm/RIU and 369 nm/RIU were achieved by reflection and transmission spectrum measurements, respectively. The high sensitivity is due to the strong plasmon-mediated energy confinement within the interface between the particles and the film. The possibility of wafer-scale production and high working stability achieved by the transfer process, together with the high sensitivity to the environmental RI, provides an extensive impact on the realization of universal biosensors for biological applications.
关键词： high stability,transfer process,low cost,refractive index sensors,particle-on-film structure
更新于2025-09-23 15:19:57