Review paper A comparative study of methods for establishing load handling capabilities

There has been much effort in recent years to quantify manual handling capabilities. Four main techniques have been used to this end; biomechanical modelling; the measurement of intra-abdominal pressure; psychophysics; and metabolic/physiological criteria. The aim of this study was to compare quantitatively the data produced from the first three techniques. The comparisons were limited to bimanual, sagittal plane lifting, which of all manual handling activities has been studied the most comprehensively, except that pushing and pulling data were compared from the psychophysics and intra-abdominal pressure (‘force limits’) databases. It was found that the data from ‘force limits’ proposed weights for bimanual lifting in the sagittal plane are lower than those reported to be psychophysically acceptable except for lifting close to and around the shoulder. The closest agreement between the databases was for lifting from an origin above knuckle height. The ‘force limits’ data were found to propose weights of lift which are at a minimum when lifting with a freestyle posture from the floor whereas the psychophysical technique proposes weights which are at a maximum when lifting from the floor. The psychophysical data were found to generate compressive forces at L5/S1 according to a static sagittal plane biomechanical model about 10% in excess of the NIOSH action limit (NIOSH 1981) when lifting from the floor, although over other lifting ranges the compressive forces were less than the NIOSH action limit. Lifting the (force limits) weights generated compressive forces which were on average 55% less than the AL (range 45 to 60%) when lifting in an erect posture. The data for pushing according to the psychophysical and ‘force limits’ database showed good agreement, but for pulling the ‘force limits’ weights were considerably greater than those selected psych ophysically. The implications of these findings are discussed.     

基于虚拟仪器的T/R电源自动测试系统的设计与实现

介绍了一种基于LabVIEW的T/R电源自动测试系统的设计方法,重点阐述了该测试系统的硬件和软件的设计思想和具体实现.针对T/R电源测试涉及仪表种类多、程控接口多样的特点,系统硬件采用混合总线接口设计以适应测试需求,软件采用层次化、模块化的设计思想,并将时间片轮转和事件触发相结合,流程控制和系统状态监测相结合,对T/R电源的静态和瞬态参数输出特性进行测试.测试流程设计合理,测试效率高效且最大限度保护被测对象,测试结果稳定可靠,满足测试需求.     

Average power‐handling capability of the signal line in coplanar waveguides on polyimide and GaAs substrates including the irregular line edge shape effects

The average power‐handling capability (APHC) of the signal line in finite‐ground coplanar waveguides (FGCPWs) on polyimide and GaAs substrates is evaluated in this paper. In our approach, the ohmic loss of metal lines is characterized in different ways, and the effects of an irregular edge shape are also considered. The rise in temperature of the signal line is determined by single‐ and double‐layer thermal models, with the temperature‐dependent properties of the thermal conductivity of GaAs material treated appropriately. Parametric studies are carried out to investigate the overall effects of signal‐line width, thickness, conductivity, edge‐shape angle, and polyimide thickness on APHC. Some possible ways to enhance the APHC of these FGCPWs are also proposed. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005.     

宽温范围测量时NTC热敏电阻器R/T数学模型

NTC型热敏电阻器使用寿命长,具有很高的灵敏度,进行宽温度范围测量而又要求较高的精度时,R/T的非线性数学模型难以描述。基于最小二乘法的多项式逼近原理,以LNTT502FW热敏电阻器为实例,分段拟合出传感器在(-20～80℃)使用环境下的数学模型,拟和数据相对误差较小,能满足测量要求。     

A millimeter‐wave CMOS power amplifier design using high‐Q slow‐wave transmission lines

A three‐stage 60‐GHz power amplifier (PA) has been implemented in a 65 nm Complementary Metal Oxide Semiconductor (CMOS) technology. High‐quality‐factor slow‐wave coplanar waveguides (S‐CPW) were used for input, output and inter‐stage matching networks to improve the performance. Being biased for Class‐A operation, the PA exhibits a measured power gain G of 18.3 dB at the working frequency, with a 3‐dB bandwidth of 8.5 GHz. The measured 1‐dB output compression point (OCP_1dB) and the maximum saturated output power P_sat are 12 dBm and 14.2 dBm, respectively, with a DC power consumption of 156 mW under 1.2 V voltage supply. The measured peak power added efficiency PAE is 16%. The die area is 0.52 mm² (875 × 600 μm²) including all the pads, whereas the effective area is only 0.24 mm². In addition, the performance improvement of the PA in terms of G, OCP_1dB, P_sat, PAE and the figure of merit using S‐CPW instead of thin film microstrip have been demonstrated. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:99–109, 2016.     

毫米波收发组件微组装激光三维扫描技术研究

毫米波收发组件微组装工艺复杂,芯片装配位置精度是影响收发组件整体性能的薄弱环节,自动化三维扫描技术是解决该问题的有效途径。将线激光轮廓传感器和线性模组结合,搭建一体化毫米波收发组件微组装三维扫描测量系统,实现了收发组件芯片的自动化在线测量和轮廓提取。该项技术有效解决了传统收发组件装配精度检测视野范围小、扫描速率低、人工干预严重等问题,提高了测量速度和测量精度,实现了收发组件装配加工与检测自动化系统的集成,可满足雷达系统装备高可靠性、高环境适应性的要求。     

一种SET/CMOS混合器件模型的建立及特性分析

本文基于一种单电子晶体管数学模型（改进的MIB模型），实现其SPICE宏模型。提出一种改进型SET／CMOS混合器件模型，并用SPICE对其I-V特性进行了仿真验证，仿真结果证实了电流与电压具有线性关系。此混合模型的线性电流区可以在积分器以及滤波器电路中得到应用。     

T/R组件自动测试系统的研制

论述了有源相控阵雷达T/R组件自动测试系统的组成和原理,包括脉冲S参数自动测试分系统原理和非S参数自动测试分系统集成技术.介绍了PNA脉冲网络分析仪自动控制的实现和系统测试软件的设计.     

T/R组件电老练测试系统设计

T/R组件电老练测试系统主要用于T/R组件的研制和生产。针对T/R组件电老练测试过程中工作量大、耗时长的问题,提出了一种可批量电老练的组合式T/R组件电老练测试系统解决方案,对电老练测试系统进行了开发验证。设备为组合机柜式结构,功能上分为电老练单元区、电源仪表区和人机交互区,可实现T/R组件在预设条件(供电、射频、脉冲和温度等)下规定时长的电老练测试。测试软件是基于自适应调节控制算法的并行测试技术实现电老练自动测试管理,并基于IVI技术进行仪器仪表的控制接口封装,实现24通道T/R组件产品老练过程中的实时数据采集、处理、显示、存储功能。系统采用模块化结构,可根据需要灵活配置;软件平台界面接口丰富、开放程度高,具备良好的维护性和拓展性。实际应用表明此系统满足T/R组件电老练测试各项指标要求;与传统方法相比,自动化程度高,能够较大程度地提高T/R组件电老练测试效率,具备较强的实用性。     

Frequency‐dependent maximum average power‐handling capabilities of single and edge‐coupled microstrip lines on low‐temperature co‐fired ceramic (LTCC) substrates

The frequency‐dependent maximum average power‐handling capabilities (APHCs) of single and edge‐coupled microstrip lines (MLs) on low‐temperature co‐fired ceramic (LTCC) substrates are investigated in this article. Although LTCCs have excellent high‐frequency performance, the thermal conductivity is about 2.0–3.0 W/m°C, which is much smaller than that of sapphires, alumina, silicon, and GaAs. The method used to predict the APHC is based on the calculated conductive and dielectric attenuation constants for different modes, and the proposed multilayer thermal model for the temperature rise. Numerical investigations are carried out to examine the effects of geometric and physical parameters on the wideband pulse responses and maximum APHC for single finite‐ground thin‐film and coupled MLs, respectively. Methodologies to enhance the power‐handling capability which are useful in the design of high‐density microstrip interconnects on or embedded in multi‐layer LTCCs are proposed. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006.     

相控阵雷达T/R组件多总线自动测试系统设计

针对有源相控阵雷达数量巨大T/R组件参数自动测试与数据分析需求,对混合多总线自动测试系统进行了研究;进行了典型T/R组件性能参数与测试仪器设备需求分析,T/R组件多总线自动测试系统硬件和软件系统设计,分析了系统误差及修正策略;该系统采用通用测试仪器结合专用测试控制单元的模式,将GPIB、LXI、USB总线脉冲功率计、噪声系数测试仪、矢量网络分析仪等测试仪器集成到控制台上,利用计算机进行测试过程控制,完成T/R组件的自动测试硬件设计;系统软件设置资源管理、自动校准、自动测试、手动测试和数据管理功能,有效提高了系统配置与数据分析处理能力;测试实验结果表明,采用自动测试大大降低了工作量,基于损耗数据修正的误差处理方法能有效保证测试精度。     

A high efficiency inductor‐less broadband fully integrated CMOS power amplifier

This work presents the design and implementation of a novel broadband completely inductor‐less 300 MHz–2.4 GHz power amplifier (PA) in 180 nm CMOS, primarily for applications in the ultrahigh frequency (UHF) industrial scientific and medical band. This is capable of delivering up to 15.6 dBm saturated output power with an associated peak power added efficiency of 31% in measurement. Although amplifiers with higher output power have been reported, this amplifier occupies only 0.086 mm² and does not require any off chip component for its operation, even at the UHF band. It also achieves the highest power density among a similar class of PA's below 10 GHz. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:311–320, 2015.     

High power GaN‐HEMT SPDT switches for microwave applications

In this article, the design, fabrication, and on‐wafer test of X‐Band and 2–18 GHz wideband high‐power SPDT MMIC switches in AlGaN/GaN technology are presented. The switches have demonstrated state‐of‐the‐art performance and RF fabrication yield better than 65%. Linear and power measurements for different control voltages have been reported and an explanation of the dependence of the power performances on the control voltage is given. In particular, the X‐band switch exhibits a 0.4 dB compression level at 10 GHz when driven by a 38 dBm input signal. The wideband switch shows a compression level of 1 dB at an input drive higher than 38 dBm across the entire bandwidth. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009.     

基于自适应LS-SVM的雷达T/R组件热管冷却故障诊断系统设计

传统雷达T/R组件热管冷却故障诊断系统受到表面振动信号干扰,存在诊断精度较差的问题,针对该问题,提出了基于自适应LS-SVM的雷达T/R组件热管冷却故障诊断系统设计。根据雷达T/R组件热管冷却工作原理,设计该故障检测系统的结构和功能,其中系统设备是由数字化收发芯片、VXI总线多DSP并行处理模块、控制电路和故障诊断电路构成的,通过数字化收发芯片,产生相应脉冲压缩雷达信号,采用TMS302VC5409型号芯片设计的DSP并行处理模型,对缺少上拉电阻的中断输入口设置多个引脚,将信号由电缆传送至驱动电路中,达到雷达波束控制目的。采用霍尔元件对电路进行诊断,经过故障样本特征提取,引用自适应加权 LS-SVM,确定故障类型,根据诊断流程,完成故障诊断系统设计。通过实验结果可知,该系统最低诊断精度也可达到92%以上,为雷达稳定运行提供支持。     

A study of two penalty-parameterless constraint handling techniques in the framework of MOEA/D

Penalty functions are frequently employed for handling constraints in constrained optimization problems (COPs). In penalty function methods, penalty coefficients balance objective and penalty functions. However, finding appropriate penalty coefficients to strike the right balance is often very hard. They are problems dependent. Stochastic ranking (SR) and constraint-domination principle (CDP) are two promising penalty functions based constraint handling techniques that avoid penalty coefficients. In this paper, the extended/modified versions of SR and CDP are implemented for the first time in the multiobjective evolutionary algorithm based on decomposition (MOEA/D) framework. This led to two new algorithms, CMOEA/D-DE-SR and CMOEA/D-DE-CDP. The performance of these new algorithms is tested on CTP-series and CF-series test instances in terms of the HV-metric, IGD-metric, and SC-metric. The experimental results are compared with NSGA-II, IDEA, and the three best performers of CEC 2009 MOEA competition, which showed better and competitive performance of the proposed algorithms on most test instances of the two test suits. The sensitivity of the performance of proposed algorithms to parameters is also investigated. The experimental results reveal that CDP works better than SR in the MOEA/D framework.     

Design and analysis of a WLAN CMOS power amplifier using multiple‐gated transistor technique

This article focused on 5.2 GHz highly integrated power amplifier for IEEE 802.11a WLAN application. Multiple‐gated transistor technique was used to improve linearity. A new approach for choosing the bias voltage of auxiliary transistor by analyzing the shift of gate bias is used in the design. The simulated results of the proposed two‐stage differential power amplifier indicate 25.28 dBm P_1‐dB, 32.87% PAE, and 26.18 dBm saturated output power with a 5.2 dB P_1‐dB improvement compared to conventional single transistor amplifier. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.     

基于E/R模型的多维数据概念模型的研究

首先对ME／R模型作了详细的介绍，然后结合实际应用，详细介绍了ME／R模型到星型结构的映射，最后与其它多维概念模型作了一个简单的对比。     

A comparative study of two state-of-the-art sequence processing techniques for hand gesture recognition

In this paper, we address the problem of the recognition of isolated, complex, dynamic hand gestures. The goal of this paper is to provide an empirical comparison of two state-of-the-art techniques for temporal event modeling combined with specific features on two different databases. The models proposed are the Hidden Markov Model (HMM) and Input/Output Hidden Markov Model (IOHMM), implemented within the framework of an open source machine learning library (www.torch.ch). There are very few hand gesture databases available to the research community; consequently, most of the algorithms and features proposed for hand gesture recognition are not evaluated on common data. We thus propose to use two publicly available databases for our comparison of hand gesture recognition techniques. The first database contains both one- and two-handed gestures, and the second only two-handed gestures.     

A comparative study of the robustness of two pose estimation techniques

The paper presents an analysis of the stability of pose estimation. Stability is defined as sensitivity of the pose parameters towards noise in image features used for estimating pose. The specific emphasis of the analysis is on determining {how the stability varies with viewpoint} relative to an object and to understand the relationships between object geometry, viewpoint, and pose stability. Two pose estimation techniques are investigated. One uses a numerical scheme for finding pose parameters; the other is based on closed form solutions. Both are “pose from trihedral vertices” techniques, which provide the rotation part of object pose based on orientations of three edge segments. The analysis is based on generalized sensitivity analysis propagating the uncertainty in edge segment orientations to the resulting effect on the pose parameters. It is shown that there is a precomputable, generic relationship between viewpoint and pose stability, and that there is a drastic difference in stability over the range of viewpoints. This viewpoint variation is shared by the two investigated techniques. Additionally, the paper offers an explicit way to determine the most robust viewpoints directly for any given vertex model. Experiments on real images show that the results of the work can be used to compute the variance in pose parameters for any given pose. For the predicted {instable} viewpoints the variance in pose parameters is on the order of 20 (degrees squared), whereas the variance for robust viewpoints is on the order of 0.05 (degrees squared), i.e., two orders of magnitude difference.     

Analysis and design of a fully integrated CMOS low‐noise amplifier for concurrent dual‐band receivers

This article thoroughly analyzes a concurrent dual‐band low‐noise amplifier (LNA) and carefully examines the effects of both active and passive elements on the performance of the dual‐band LNA. As an example of the analysis, a fully integrated dual‐band LNA is designed in a standard 0.18‐μm 6M1P CMOS technology from the system viewpoint for the first time to provide a higher gain at the high band in order to compensate the high‐band signal's extra loss over the air transmission. The LNA drains 6.21 mA of current from a 1.5‐V supply voltage and achieves voltage gains of 14 and 22 dB, input S₁₁ of 15 and 18 dB, and noise figures of 2.45 and 2.51 dB at 2.4 and 5.2 GHz, respectively. © 2006 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006.