一种低功耗245 GHz次谐波接收机

介绍了一种应用于气体频谱分析传感器的低功耗245 GHz次谐波接收机,该接收机具有低功耗、高线性度和高集成度的特点.该接收机由四级共基极低噪声放大器、二次次谐波无源反接并联二极管对(APDP)混频器、120GHz推推型压控振荡器-分频器链路、120 GHz功率放大器和中频放大器构成,采用了特征频率为300 GHz、最大振荡频率为500 GHz的锗硅BiCMOS工艺实现.该接收机芯片实现了10.6 dB的转换增益和13 GHz的带宽,噪声系数为20 dB,输入1dB压缩点仿真结果为-9 dBm,接收机如果不包括120 GHz压控振荡器-功率放大器链路功耗为99.6 mW,接收机包括120 GHz压控振荡器-功率放大器链路功耗为312 mW.

245 GHz接收机芯片片外测试与实验

为了实现太赫兹气体频谱分析传感器,对245 GHz次谐波接收机芯片的片外测试展开研究。建立了245 GHz次谐波接收机片外测试系统以及基于245 GHz接收机芯片及发射机芯片的气体频谱分析传感器片外展示测试系统,对245 GHz次谐波接收机芯片转换增益和带宽进行测试。片外测试系统得到15 dB转换增益和15 GHz带宽;片外展示测试系统得到9 dB转换增益和16 GHz带宽。片外测试系统和片外展示测试系统结果基本吻合。在片外展示测试系统中加入气腔,即构成气体频谱分析传感器。与现有同类型传感器相比,本文的次谐波接收机具有高增益、高带宽、集成本地振荡信号、低功耗等优势,非常适用于消费电子领域小体积的智能气体频谱分析传感器。

用于气体频谱分析传感器的245 GHz次谐波接收机

提出了一种用于气体频谱分析传感器的混频器优先的245 GHz次谐波接收机。该接收机具有高线性度、高带宽、低噪声系数、低功耗和高集成度的特点。该接收机由2次无源反接并联二极管对(APDP)次谐波混频器、120 GHz推推型压控振荡器-分频器链路和120 GHz功率放大器构成。采用特征频率/最大振荡频率为300 GHz/500 GHz的SiGe BiCMOS工艺进行实现。结果表明,该接收机芯片的转换增益为-16 dB,带宽为14 GHz,单边带噪声系数为19 dB,输入1 dB压缩点为0 dBm,功耗为213 mW。

基于双各向异性超构表面的多样化表面波

基于结构化的金属表面,即超构表面,所获得的表面波最近得到了广泛关注。它们在各种不同的频率下在集成光学回路、成像以及生物检测中都有着良好的应用前景。本文中,我们展示了一种由双各向异性超构材料单元构成的超构表面可以支持多种不同偏振模式的表面态。这个结构拥有D_(2d)点群对称性,包括了在xz和yz面内拥有镜面对称,以及在y=±x方向上拥有C_(2)旋转对称性。基于这种对称性,这个超构表面可以在k_(x)和k_(y)方向上支持横电模(TE)以及横磁模(TM)的同时支持在k_(y)=±k_(x)方向上的纯纵模以及椭偏的横电磁模(TEM)。这种超构表面上的多种表面模式可能会产生新的表面波现象以及器件应用。

Characterization of Fiber Dust Resulting from Recycling of Carbon Fiber-Reinforced Thermoplastics (CFRP) and Their Cell Toxicity

Carbon fiber-reinforced thermoplastics (CFRP) have excellent specific strength and rigidity, which has made them a popular material for lightweight construction. The growing demand for fiber-reinforced plastics (FRP) leads to the problem of the sustainable handling of FRP at the end of their life cycle. The aim of the research project was to gain knowledge about the shredding of FRP concerning the optimal machine and process design of the shredding process and the possible formation of harmful, inhalable dust fractions and WHO fibers. Toxicity should be investigated at the cellular level. The investigated shredding parameters influence the amount and length of fiber dust produced, both when shredding with a cutting mill and when shredding with a single-shaft shredder. In all investigations, an increasing rotational speed leads to an increase in the fiber dust mass or the fiber concentration. The proportion of short, respirable fibers increases, but raising the speed does not lead to a further, significant shortening of the fibers. A reduction in feedstock size leads to a slightly reduced mass of fiber dust in the ground material. A reduction in the screen size also leads to an increase in fiber dust mass and concentration. There was no recognizable cytotoxicity in the relevant concentration range up to 500 μg/cm2 and no significant induction of cell migration. This indicates minor flammable effects of the dust formed after inhalation. The biological data indicate that the WHO fibers produced by shredding are only a minor health hazard. Formally, the detected carbon fiber (CF) fragments meet the fiber definition of the legislator. However, carbon fibers currently have no specific limit value.

Mechanically Joined Extrusion Profiles for Battery Trays

In the context of electromobility,ensuring the leak tightness of assemblies is of paramount importance,particularly in bat-tery housings.Current battery housings,often featuring base assemblies crafted from extruded aluminum profiles,address the challenge of leak tightness at joints through methods like friction stir welding,a process known for its time and cost intensiveness.The aim of this study is to develop and implement a new type of extruded profile concept to produce tight base assemblies for battery housings by a longitudinal mechanical single stroke joining process.The geometry,the process and the properties of the aluminum profiles are investigated to get a joint that meets the tightness requirements and achieve high load-bearing capacities in agreement with the high homologation requirements set to vehicles with high-voltage systems.The joint is formed by means of a single stage press stroke,which eliminates the need for complex tool designs that are neces-sary for continuous joining(roll joining).Flat steel contact surfaces are used as joining tools.To evaluate the joint quality,force curves from the joining process are analyzed and the resulting joint geometries are assessed using micrographs.The resulting leak tightness of the linear joints is measured by a helium sniffer leak detector and the load-bearing capacities are investigated by shear lap and bending tests and fatigue strength test.The study also explores whether a difference in strength between the two joining partners has a positive effect on the joint properties.

Photovoltaic yield prediction using an irradiance forecast model based on multiple neural networks

In order to develop predictive control algorithms for efficient energy management and monitoring for residential grid connected photovoltaic systems, accurate and reliable photovoltaic(PV) power forecasts are required.A PV yield prediction system is presented based on an irradiance forecast model and a PV model. The PV power forecast is obtained from the irradiance forecast using the PV model. The proposed irradiance forecast model is based on multiple feed-forward neural networks. The global horizontal irradiance forecast has a mean absolute percentage error of 3.4% on a sunny day and 23% on a cloudy day for Stuttgart. PV power forecasts based on the neural network irradiance forecast have performed much better than the PV power persistence forecast model.

Metasurface interferometry toward quantum sensors

Optical metasurfaces open new avenues for the precise wavefront control of light for integrated quantum technology.Here,we demonstrate a hybrid integrated quantum photonic system that is capable of entangling and disentangling two-photon spin states at a dielectric metasurface.Via the interference of single-photon pairs at a nanostructured dielectric metasurface,a path-entangled two-photon NOON state with circular polarization that exhibits a quantum HOM interference visibility of 86±4% is generated.Furthermore,we demonstrate nonclassicality andphase sensitivity in a metasurface-based interferometer with a fringe visibility of 86.8±1.1%in the coincidence counts.This high visibility proves the metasurface-induced path entanglement inside the interferometer.Our findings provide a promising way to develop hybrid-integrated quantum technology operating in the high-dimensional mode space in various applications,such as imaging,sensing,and computing.

Metasurfaces help lasers to mode-lock

Metasurface saturable absorbers may result in versatile mode-locking that allows one to obtain stable ultrashort laser pulses with high repetition rates and peak powers,along with broadband operation,within fiber to solid-state laser cavities.

All-dielectric silicon metalens for two-dimensional particle manipulation in optical tweezers

Dynamic control of compact chip-scale contactless manipulation of particles for bioscience applications remains a challenging endeavor,which is restrained by the balance between trapping efficiency and scalable apparatus.Metasurfaces offer the implementation of feasible optical tweezers on a planar platform for shaping the exerted optical force by a microscale-integrated device.Here we design and experimentally demonstrate a highly efficient silicon-based metalens for two-dimensional optical trapping in the near-infrared.Our metalens concept is based on the Pancharatnam–Berry phase,which enables the device for polarization-sensitive particle manipulation.Our optical trapping setup is capable of adjusting the position of both the metasurface lens and the particle chamber freely in three directions,which offers great freedom for optical trap adjustment and alignment.Two-dimensional(2D)particle manipulation is done with a relatively low-numerical-aperture metalens(NA(ML)=0.6).We experimentally demonstrate both 2D polarization-sensitive drag and drop manipulation of polystyrene particles suspended in water and transfer of angular orbital momentum to these particles with a single tailored beam.Our work may open new possibilities for lab-on-a-chip optical trapping for bioscience applications and microscale to nanoscale optical tweezers.

A multi-mode super-fano mechanism for enhanced third harmonic generation in silicon metasurfaces

We present strong enhancement of third harmonic generation in an amorphous silicon metasurface consisting of elliptical nano resonators.We show that this enhancement originates from a new type of multi-mode Fano mechanism.These‘Super-Fano’resonances are investigated numerically in great detail using full-wave simulations.The theoretically predicted behavior of the metasurface is experimentally verified by linear and nonlinear transmission spectroscopy.Moreover,quantitative nonlinear measurements are performed,in which an absolute conversion efficiency as high as η_(max)≈2.8×10^(-7) a peak power intensity of 1.2 GW cm^(-2) is found.Compared to an unpatterned silicon film of the same thickness amplification factors of up to ~900 are demonstrated.Our results pave the way to exploiting a strong Fano-type multi-mode coupling in metasurfaces for high THG in potential applications.

245 GHz subharmonic receiver with on-chip antenna for gas spectroscopy application

A 2 nd transconductance subharmonic receiver for 245 GHz spectroscopy sensor applications has been proposed. The receiver consists of a 245 GHz on-chip folded dipole antenna, a CB（common base） LNA, a 2 nd transconductance SHM（subharmonic mixer）, and a 120 GHz push-push VCO with 1/64 divider. The receiver is fabricated in f;/f;= 300/500 GHz SiGe:C BiCMOS technology. The receiver dissipates a low power of 288 mW.Integrated with the on-chip antenna, the receiver is measured on-chip with a conversion gain of 15 dB, a bandwidth of 15 GHz, and the chip will be utilized in PCB board design for gas spectroscopy sensor application.

Direct Model Checking Matrix Algorithm

During the last decade, Model Checking has proven its efficacy and power in circuit design, network protocol analysis and bug hunting. Recent research on automatic verification has shown that no single model-checking technique has the edge over all others in all application areas. So, it is very difficult to determine which technique is the most suitable for a given model. It is thus sensible to apply different techniques to the same model. However, this is a very tedious and time-consuming task, for each algorithm uses its own description language. Applying Model Checking in software design and verification has been proved very difficult. Software architectures （SA） are engineering artifacts that provide high-level and abstract descriptions of complex software systems. In this paper a Direct Model Checking （DMC） method based on Kripke Structure and Matrix Algorithm is provided. Combined and integrated with domain specific software architecture description languages （ADLs）, DMC can be used for computing consistency and other critical properties.

Self-assembly of highly ordered DNA origami lattices at solid-liquid interfaces by controlling cation binding and exchange

The surface-assisted hierarchical self-assembly of DNA origami lattices represents a versatile and straightforward method for the organization of functional nanoscale objects such as proteins and nanoparticles.Here,we demonstrate that controlling the binding and exchange of different monovalent and divalent cation species at the DNA-mica interface enables the self-assembly of highly ordered DNA origami lattices on mica surfaces.The development of lattice quality and order is quantified by a detailed topological analysis of high-speed atomic force microscopy(HS-AFM)images.We find that lattice formation and quality strongly depend on the monovalent cation species.Na^(+)is more effective than Li^(+)and K^(+)in facilitating the assembly of high-quality DNA origami lattices,because it is replacing the divalent cations at their binding sites in the DNA backbone more efficiently.With regard to divalent cations,Ca^(2+)can be displaced more easily from the backbone phosphates than Mg^(2+)and is thus superior in guiding lattice assembly.By independently adjusting incubation time,DNA origami concentration,and cation species,we thus obtain a highly ordered DNA origami lattice with an unprecedented normalized correlation length of 8.2.Beyond the correlation length,we use computer vision algorithms to compute the time course of different topological observables that,overall,demonstrate that replacing MgCl_(2) by CaCl_(2) enables the synthesis of DNA origami lattices with drastically increased lattice order.

Generalised tanh-shaped hyperbolic potential: Klein–Gordon equation's bound state solution

The development of potential theory heightens the understanding of fundamental interactions in quantum systems.In this paper,the bound state solution of the modified radial Klein–Gordon equation is presented for generalised tanh-shaped hyperbolic potential from the Nikiforov–Uvarov method.The resulting energy eigenvalues and corresponding radial wave functions are expressed in terms of the Jacobi polynomials for arbitrary l states.It is also demonstrated that energy eigenvalues strongly correlate with potential parameters for quantum states.Considering particular cases,the generalised tanh-shaped hyperbolic potential and its derived energy eigenvalues exhibit good agreement with the reported findings.Furthermore,the rovibrational energies are calculated for three representative diatomic molecules,namely H2,HCl and O2.The lowest excitation energies are in perfect agreement with experimental results.Overall,the potential model is displayed to be a viable candidate for concurrently prescribing numerous quantum systems.

Investigations on the aging behavior of transparent bioplastics for optical applications

In this study,the optical properties of transparent bioplastics have been investigated.The long-term technological goal is to establish biopolymers in a new market segment for demanding optical applications and to contribute to a more sustainable economy.A collection of transparent bioplastics has been tested with respect to the long-term stability and the possibility of an application in optical components for LED lighting.The focus of materials testing was on the influence of short wavelength visible radiation as well as thermal loads.The results show,that some materials may be candidates for subsequent feasibility studies.To the best of our knowledge,the application of such polymers in complex technical products and in particular in luminaires has not yet been realized.The use of bio-based plastics for optical components therefore represents a novelty and has a high development potential.