Spin-controlled generation of a complete polarization set with randomly-interleaved plasmonic metasurfaces

Optical metasurfaces,comprising subwavelength quasi-planar nanostructures,constitute a universal platform for manipulating the amplitude,phase,and polarization of light,thus paving a way for the next generation of highly integrated multifunctional optical devices.In this work,we introduce a reflective metasurface for the generation of a complete(angularly resolved)polarization set by randomly interleaving anisotropic plasmonic meta-atoms acting as nanoscale wave plates.In the proof-of-concept demonstration,we achieve multidirectional beam-steering into different polarization channels forming a complete set of polarization states,which can also be dynamically altered by switching the spin of incident light.The developed design concept represents a significant advancement in achieving flat polarization optics with advanced functionalities.

Interleaved-Connected Split Planar Resonant Inductor Design in 1 kV SiC LLC Converters

Design method of split planar resonant inductor in 1 kV SiC logical link control(LLC)converter is proposed,which ensures the converter power density of 93.59 W/in^3 and peak efficiency of 95.73%.Split resonant inductor helps to provide symmetrical resonant current by symmetrical impedance,and improves the distortion of resonant current,which ensures the efficiency of the whole converter.An interleaved winding connecting scheme improves the power density of the planar magnets,which contributes to power density improvement.Design method and calculation process of such split planar resonant inductor are provided.To verify the feasibility of the proposed design method,a 1 kV/48 V 6.6 kW,210 k Hz SiC LLC prototype was built,and the experimental results are given.

Research on Parallel Interleaved Inverters with Discontinuous Space-Vector Modulation

Parallel converter can significantly increase the capacity of the converter and improve the power quality of AC side, but the circulation which can lead to high switching loss and even damage the devices will easily exist in the direct parallel converters. In this paper, the average model of parallel interleaved inverters system to analyze the circulation current is shown, and the cross current is relevant to DC-bus voltage and the overlap time of zero vectors in the switching period. Based on this observation, a discontinuous space vector modulation without using zero vectors (000) is eliminate and suppress the zero-sequence current to entire system. Finally, the effectiveness of modulation strategy is verified by the simulations in this paper.

High Power Interleaved Boost Converter for Photovoltaic Applications

Interfacing DC sources to load/power grid requires DC converters that produce minimum level of current ripples. This is to limit the losses and hence increase the life span of these sources. This article proposes a simple inter-leaved boost converter that interfaces PhotoVoltaic (PV) module into a common DC-link. The article also addresses the faulty mode operation of the proposed circuit while advising the appropriate remedy actions. A MATLAB and Simulink dynamic platform are used to simulate the transient performance of the proposed converter. The results revealed the effectiveness and the viability of the proposed converter in reducing the ripples in the PV current without employing bulky input inductors or increasing the switching frequency.

Complexity Reduced MIMO Interleaved SC-FDMA Receiver with Iterative Detection

In this paper, we propose the receiver structure for Multiple Input Multiple Output (MIMO) Interleaved Single Carrier-Frequency Division Multiple Access (SC-FDMA) where the Frequency Domain Equalization (FDE) is firstly done for obtaining the tentative decision results and secondly using them the Inter-Symbol Interference (ISI) is cancelled by ISI canceller and then the Maximum Likelihood Detection (MLD) is used for separating the spatially multiplexed signals. Furthermore the output from MLD is fed back to ISI canceller repeatedly. In order to reduce the complexity, we replace the MLD by QR Decomposition with M-Algorithm (QRD-M) or Sphere Decoding (SD). Moreover, we add the soft output function to SD using Repeated Tree Search (RTS) algorithm to generate soft replica for ISI cancellation. We also refer to the Single Tree Search (STS) algorithm to further reduce the complexity of RTS. By examining the BER characteristics and the complexity reduction through computer simulations, we have verified the effectiveness of proposed receiver structure.

A Timing Skew Calibration Scheme in Time-Interleaved ADC

This paper proposes a digital background calibration scheme for timing skew in time-interleaved analog-to-digital converters (TIADCs). It detects the relevant timing error by subtracting the output difference with the sum of the first derivative of the digital output. The least-mean-square (LMS) loop is exploited to compensate the timing skew. Since the calibration scheme depends on the digital output, all timing skew sources can be calibrated and the main ADC is maintained. The proposed scheme is effective within the entire frequency range of 0 ? fs/2. Compared with traditional calibration schemes, the proposed approach is more feasible and consumes significantly lesser power and smaller area.

Multiple-Symbol Interleaved RS Codes and Two-Pass Decoding Algorithm

For communication systems with heavy burst noise, an optimal Forward Error Correction(FEC) scheme is expected to have a large burst error correction capability while simultaneously owning moderate random error correction capability. This letter presents a new FEC scheme based on multiple-symbol interleaved Reed-Solomon codes and an associated two-pass decoding algorithm. It is shown that the proposed multi-symbol interleaved Reed-Solomon scheme can achieve nearly twice as much as the burst error correction capability of conventional single-symbol interleaved Reed-Solomon codes with the same code length and code rate.

Fuzzy Based Interleaved Step-up Converter for Electric Vehicle

This work focuses on the fuzzy controller for the proposed three-phase interleaved Step-up converter(ISC).The fuzzy controller for the proposed ISC converters for electric vehicles has been discussed in detail.The proposed ISC direct current(DC-DC)converter could also be used in automobiles,satellites,industries,and propulsion.To enhance voltage gain,the proposed ISC Converter combines boost converter and interleaved converter(IC).This design also reduces the number of switches.As a result,ISC converter switching losses are reduced.The proposed ISC Converter topology can produce a 143 V output voltage and 1 kW of power.Due to the high voltage gain of this converter design,it is suitable for medium and high-power systems.The proposed ISC Converter topology is simulated in MATLAB/Simulink.The simulated output displays a high output voltage.But the output voltage contains maximum ripples.Fuzzy proposes an ISC Converter which makes closed loop responsiveness and reduces the output voltage ripple.The proposed ISC converter has the lowest ripple output voltage,which is less than 2%,because the duty cycle is regulated using the fuzzy logic controller.It offers high voltage gain,minimal ripple,and low switching loss.The performance of the proposed converter is compared to that of the fuzzy and Pro-portional Integral(PI)controllers implemented in MATLAB.

Identification of Typical Rice Diseases Based on Interleaved Attention Neural Network

Taking Jiuhong Modern Agriculture Demonstration Park of Heilongjiang Province as the base for rice disease image acquisition,a total of 841 images of the four different diseases,including rice blast,stripe leaf blight,red blight and bacterial brown spot,were obtained.In this study,an interleaved attention neural network(IANN)was proposed to realize the recognition of rice disease images and an interleaved group convolutions(IGC)network was introduced to reduce the number of convolutional parameters,which realized the information interaction between channels.Based on the convolutional block attention module(CBAM),attention was paid to the features of results of the primary group convolution in the cross-group convolution to improve the classification performance of the deep learning model.The results showed that the classification accuracy of IANN was 96.14%,which was 4.72%higher than that of the classical convolutional neural network(CNN).This study showed a new idea for the efficient training of neural networks in the case of small samples and provided a reference for the image recognition and diagnosis of rice and other crop diseases.

Adaptive blind gain correction of time-interleaved ADCs forwide-band communication applications

High spectral efficiency is essential in design of multimedia communication systems such as L-band mobile in addition to various requirements of transmission quality. Time-interleaved A/D converter （TI-ADC） is an effective candidate to implement wide-band ADC with relatively slow circuits accounting for digital spectrum management. However, practical performance of TI-ADC is largely limited because of mismatches between different channels originated from manufacturing process variations. In this paper, a blind adaptive method is proposed to correct gain mismatch errors in TI-ADC, and it is verified through simulations on a two-channel TI-ADC. In proposed method, gain mismatch error is estimated and corrected in an adaptive scheme. Proposed compensated T1-ADC architecture is structurally very simple and hence suitable for realiza- tion in integrated circuits. Besides, proposed digital compensation algorithm not only is computationally efficient but also provides an improvement of 32.7 dB in the performance of two-channel TI ADC.

SPLIT-ADC BASED DIGITAL BACKGROUND CALIBRATION FOR TIME-INTERLEAVED ADC

A novel Time-Interleaved Analog-to-Digital Converter (TIADC) digital background calibration for the mismatches of offsets, gain errors, and timing skews based on split-ADC is proposed. Firstly, the split-ADC channels in present TIADC architecture are designed to convert input signal at two different channel sampling rates so that redundant channel to facilitate pair permutation is avoided. Secondly, a high-order compensation scheme for correction of timing skew error is employed for effective calibration to preserve high-resolution when input frequency is high. Numerical simulation performed by MATLAB for a 14-bit TIADC based on 7 split-ADC channels shows that Signal-to-Noise and Distortion Ratio (SNDR) and Spurious Free Dynamic Range (SFDR) of the TIADC achieve 86.2 dBc and 106 dBc respectively after calibration with normalized input frequency near Nyquist frequency.

Improved Interleaved Single-Ended Primary Inductor-Converter forSingle-Phase Grid-Connected System

The generation of electricity based on renewable energy sources,parti-cularly Photovoltaic(PV)system has been greatly increased and it is simply insti-gated for both domestic and commercial uses.The power generated from the PV system is erratic and hence there is a need for an efficient converter to perform the extraction of maximum power.An improved interleaved Single-ended Primary Inductor-Converter(SEPIC)converter is employed in proposed work to extricate most of power from renewable source.This proposed converter minimizes ripples,reduces electromagnetic interference due tofilter elements and the contin-uous input current improves the power output of PV panel.A Crow Search Algo-rithm(CSA)based Proportional Integral(PI)controller is utilized for controlling the converter switches effectively by optimizing the parameters of PI controller.The optimized PI controller reduces ripples present in Direct Current(DC)vol-tage,maintains constant voltage at proposed converter output and reduces over-shoots with minimum settling and rise time.This voltage is given to single phase grid via 1�Voltage Source Inverter(VSI).The command pulses of 1�VSI are produced by simple PI controller.The response of the proposed converter is thus improved with less input current.After implementing CSA based PI the efficiency of proposed converter obtained is 96%and the Total Harmonic Distor-tion(THD)is found to be 2:4%.The dynamics and closed loop operation is designed and modeled using MATLAB Simulink tool and its behavior is performed.

Design and Experimentation of FPGA-Based Soft-Switched Interleaved Boost Converter for Telecommunication System

This paper proposes the design and experimentation of digital control of soft-switched interleaved boost converter using FPGA for Telecommunication System. The switching devices in the proposed converter are turned on and off with Zero Voltage Switching (ZVS) and Zero Current Switching (ZCS) respectively. The circuit is operated in Continuous Conduction Mode (CCM) with various load ranges having duty cycle of more than 50%. The proposed converter is studied by developing the simulation module in MATLAB/SIMULINK. A PI controller is designed and implemented in FPGA to obtain a regulated DC output for line and load variations. Simulation and experimentation results are verified with a prototype development of the proposed converter. The results indicate that the converter performance is enhanced with closed loop control.

Weight and Efficiency Optimized DC/DC Converter Based on Multiple Interleaved Channels

Today, energy saving is one of the main objectives for engineers. In the case of mobile applications, energy can be saved by two different ways： decreasing the total masse of the system and increasing the efficiency of the overall system. This paper presents two optimization strategies to design a predefined multichannel structure of a boost converter which is dedicated to a solar airplane and used to interface PV panels and the battery system. The first strategy is a multi-criterion method that is able to trace the dependency between the converter＇s efficiency and its power density through the intermediary of the Pareto front. The second method, a mono-criterion approach, maximizes efficiency while respecting the constraint imposed on power density. The mono-criterion method that is applied to maximizing the European efficiency criterion showed that an increase in the number of channels enhanced the quantity of energy collected over a day by increasing the power density of the converter. At the end of the paper, the optimal design calculated was built to give an example of the result obtained by this design methodology. The results of the efficiency measurements made on a realized prototype are presented in this paper.

Achievable secrecy rate of bit-interleaved coded modulation schemes

We study the impact of various modulation mapping strategies and signal constellation shapes on the se- crecy rates achievable with bit-interleaved coded modulation （BICM） schemes. Transmission over an ergodic Rayleigh fading channel is assumed throughout this work. Various constellations and mapping techniques are considered in this work to maximize the capacity difference between the main channel and the eavesdropper channel, rather than to opti- mize the capacity of both channels. We show that in terms of achievable secrecy rate, Gray and Quasi-Gray mappings only perform Well at low SNR but outperformed by other mapping techniques when SNR increases. The proper design of signal mapping can significantly enhance the achievable secrecy rate in BICM schemes. It is indicated that the key parameter to the secrecy rate of a BICM system is the distance spectrum of Euclidean distances for mappings.

新兴光子器件——Interleaver

系统介绍了新兴光子器件———Interleaver的特性、实现方法及其在DWDM系统中的应用。结合课题组的工作 ,主要介绍了光纤熔锥非平衡M Z干涉仪型、偏振光干涉晶体双折射型和迈克耳逊干涉仪 +GT反射镜型三种实现方案。

基于非均匀取样布拉格光纤光栅Interleaver的设计

对于光纤通信领域有限的带宽资源,波分复用与解复用器件Interleaver是未来密集型波分复用(DWDM)光纤通信网中的关键器件。为此结合非均匀取样光栅Interleaver的基本设计原理,运用耦合模理论和矩阵传输方法对非均匀取样光纤布拉格光栅的传输特性进行了数值模拟计算,并设计了信道间隔为0.8nm的设计实例,反射谱峰值均匀达到80%～95%,传输通道间隔稳定均匀,时延和色散均匀,时延抖动小于200ps。

一种改善MZI型Interleaver滤波特性新结构的理论研究

根据最近研究的一种改进型光纤Mach-Zehnder干涉仪(MZ1)型Interleaver存在的问题,提出一种改善其滤波特性的新结构．对其原理和相关参数进行了模拟分析,结果表明新结构的光谱形状与隔离度都比原结构有较大改善,且保持了信道的对称性．本文分析计算的结果对器件的优化设计具有实际的指导意义．

非对称M-Z型Interleaver输出光谱特性分析

分析了两级串联非对称马赫-曾德尔(Mach-Zehnder)干涉型Interleaver的透过率函数的输出形态,采用梯形波近似理论,利用傅里叶级数展开的方法选取适当的干涉臂的光程差比例和耦合器耦合比,可得到输出波形通带平坦,透射率形态近似于方波,同时分析了两个臂长差对输出光谱的影响.模拟结果表明:此结构的Interleaver的输出光谱的平坦特性对两耦合器的耦合比不敏感;两个臂长差对输出光谱的影响程度不同,控制严格的干涉臂的光程差比例是输出光谱的保证平坦特性的关键,模拟结果同实验测试曲线相吻合.

用傅立叶光学展宽Interleaver的带宽

简要介绍了Interleaver的原理和应用。在推导、比较马赫-泽德干涉仪型和双折射晶体型Interleaver的传输矩阵的基础上,提出并分析了用傅立叶光学展宽Interleaver带宽的方法。