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A novel method for parameter estimation of maneuvering targets is proposed in this paper to eliminate the influence of spectrum spread on image focusing. In this method, the received signal in a range cell is modelled as a multi-component linear frequency modulated (LFM) signal after range compression and motion compensation, and then a new transform, namely, Doppler Lv's transform (LVT) is applied...
A new parameter estimation algorithm based on Sub-band Dual Frequency Conjugate and LVT (SDFC-LVT) operation is proposed for fast moving targets. A new synthetic signal is constructed by the essential operations, including spectrum division, frequency shifting, and conjugate multiplications. After that, Keystone transform and LVT operator are performed on the constructed signal to attain the estimates...
Cascade H-bridge multilevel converter can be directly connected to the medium voltage grid, which can effectively improve the voltage stability of the power system. However, the imbalance of the DC-link voltage of each H-bridge module due to the power loss difference is a challenging issue, which would seriously affect the output performance of the cascade multilevel converter. Software based scheme...
The study focus on the process of metal electroplating on copper substrate to assemble LED chips and molding PET-copper foil to implement a flexible module with LED chips. The process can be divided into two parts,-assembling process and molding process. The LEDs are integrated on copper foil which can deal with the heat dissipation problem effectively. The metal electroplating on copper circuitry...
We propose an asymmetric write algorithm of step-down set/step-up reset without verify for the first time. The demonstration is carried out on a 128Kb test macro of AlOx/WOx bi-layer ReRAM fabricated based on 0.18µm logic process. The set and reset energy per bit are reduced by 34% and 20% respectively. The set and reset access time decrease by 54% and 32% respectively. The mean value of endurance...
The study focus on the process of metal electroplating on copper substrate to assemble LED chips and molding PET-copper foil to implement a flexible module with LED chips. The process can be divided into two parts,-assembling process and molding process. The LEDs are integrated on copper foil which can deal with the heat dissipation problem effectively. The metal electroplating on copper circuitry...
This paper presents an optimal negative current control for four-phase interleaved bi-directional converters to achieve soft-switching features. Four-phase buck/boost converters with bi-directional operation and in discontinuous conduction mode (DCM) are designed and implemented. The optimal negative current is determined and controlled to reduce reactive power loss, while achieves ZVS and ZCS turn-on...
GaN is a promising material for LED lighting [1], high voltage power electronics [2] and high power RF applications [3]. GaN HEMT and MOS-HEMT with AlGaN [4] or AlInN [5] polarization layer have been widely studied. In this work we investigate the effects of Al0.83In0.17N polarization layer thickness scaling on the device characteristics of Al0.83In0.17N/AlN/GaN MOS-HEMTs on SiC substrates. We have...
Streaming electrification phenomenon seen in power transformers results from forced oil circulation. This phenomenon has been extensively investigated since it was identified as one of the failure reasons for large power transformers. The majority of the published research focused on the streaming electrification of mineral oils. Taking into account the potential increase in the voltage level and...
To consider the complex system integration of LED luminaires, a novel analysis method combined with reliability test is presented. Initially, the whole system is divided into three subsystems (Drive, fixture and LED light source) so that reliability test can be conducted on the objective subsystem with a stress level as high as possible. And further step stress accelerated degradation test (SSADT)...
A manipulator with variable stiffness allows the manipulator to adjust its stiffness to fulfill different task requirements. In this paper, a cable-driven manipulator with the ability to significantly regulate its stiffness through tension manipulation is introduced. Variable stiffness is achieved by attaching a novel variable stiffness device along each driving cable, in which the stiffness of the...
High power light-emitting diode (LED) has gained more and more applications because LED has many advantages over traditional light sources. However, it is extremely time-consuming and complicated to evaluate the LED luminaires reliability, in particular, the luminous degradation. In this work, a novel hybrid method, which combines the thermal modeling and temperature measurement, is proposed to estimate...
Multi-level modulation on orthogonal frequency division multiplexing (OFDM) signals is experimentally demonstrated by an integrated silicon Mach-Zehnder modulator. The measured bit error rate is well below the forward error correction (FEC) threshold.
We have experimentally demonstrated a self-starting mode-locked fiber laser source operating at 1503 nm with 9 nm output bandwidth. The mode-locked laser works stably with a pumping threshold of 225 mW at 980 nm.
In many antenna application cases, the phase center is not an important parameter, however, in some special cases, antenna phase center should be measured precisely. In this paper, a novel method for antenna phase center calculation is proposed. The calculation examples validate that this method is efficient and useful for actual engineering application.
We investigated dislocation-related electronic states induced by dislocation motion in CdTe-based semiconductors. Dislocations cause various types of electronic defect states in the bandgap of semiconductors, namely, defects created by different types of dislocations, and those due to an impurity or native defect segregated around the dislocations. The aim of this work was to further clarify, on the...
In this letter, a balanced-to-unbalanced (balun) bandpass filter (BPF) with capacitive loaded coupled lines is presented. The bandpass filter is realized by two half-wavelength resonators which are coupled at their ends. Thus, it adds extra transmission zeros to the filter, which can effectively reject strong interference in the stopband. By using the symmetric and skew-symmetric feed structures,...
With rapid development of lighting emitting diode (LED) market, more people are focusing on reliability testing method of LED luminaries system. Based on the previous exploration, to assess the whole system reliability with a fast way, authors propose to divide the system into several subsystems, and then carry out step stress accelerated testing (SSAT) to get failure mechanism and reliability distribution...
In the traditional electronic packaging structure optimization model, the life cycle energy consumption and emission goals do not include in the optimal objectives. For the sustainable development purpose, it is necessary to consider the life cycle energy consumption and emission in the electronic packaging structure optimization. In this paper, the necessity and the model of taking into account of...
In this paper, a robot calibration method is proposed where the effects of joint compliance is taken into account when formulating the model. The calibration process identifies the parameters describing the relative poses of the local frames attached to the links of the robot and the parameters determining joint deflections such as joint stiffness, the mass and center of gravity of each link. A kinematic...
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