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ultra-fine tuning
摘要： Researchers from Xi’an University of Technology in China, alongside researchers from the ENSEIRB and the IERF in France, propose an auto-tuning network for a phased-array high intensity focused ultrasound (HIFU) system based on a variable synchronous switched capacitor. The novel system is capable of automatically compensating for the reactive power and impedance drifts, caused by temperature fluctuations and manufacturing errors, in circuit transducers and complies with magnetic resonance imaging (MRI) compatibility regulations.
关键词： phased-array,variable synchronous switched capacitor,high-intensity focused ultrasound,HIFU,Auto-tuning network,MRI compatibility
更新于2025-09-23 15:21:01
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DESIGN AND REALIZATION OF CIRCULAR POLARIZED SIW SLOT ARRAY ANTENNA FOR CUBESAT INTERSATELLITE LINKS
摘要： This paper presents the design and fabrication of an antenna based on Substrate Integrated Waveguide (SIW) for intersatellite crosslinks in C-band. The entire antenna consists of two elements of SIW slots array that is fed by a hybrid 3 dB directional coupler. The entire SIW slots array antenna is circularly polarized (CP), and each element has four longitudinal slots. The element’s e?ective ?eld matching is realized with a microstrip to SIW transition. The antenna design has been evaluated with its return loss, gain plot, and radiation pattern characteristics to validate the fabricated antenna. The fabricated prototype antenna radiates a left-handed circularly polarized (LHCP) electromagnetic wave with the peak gain of 5 dB and o?ers approximately 2% AR bandwidth around 5 GHz.
关键词： circularly polarized (CP),intersatellite links,slot array antenna,CubeSat,Substrate Integrated Waveguide (SIW)
更新于2025-09-23 15:21:01
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A blue-phase liquid crystal lens array based on dual square ring-patterned electrodes
摘要： We propose a blue-phase liquid crystal (BPLC) lens array based on dual square ring-patterned electrodes. A high dielectric constant layer is used to smoothen out the horizontal electric field and reduce the operating voltage. By creating a potential difference between the dual square ring-patterned electrodes, gradient electric fields are generated and lens-like phase profile is obtained. Besides, the focal length of the BPLC lens is adjustable with voltage changes and all simulation results indicate that the BPLC lens array is polarisation-insensitive.
关键词： polarisation-insensitive,lens array,Blue phase,liquid crystal
更新于2025-09-23 15:21:01
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[IEEE 2018 2nd International Conference on Biomedical Engineering (IBIOMED) - Bali, Indonesia (2018.7.24-2018.7.26)] 2018 2nd International Conference on Biomedical Engineering (IBIOMED) - Design of Mass-Sensitive Sensor Array for Biomedical Application: Sensing Lipoproteins
摘要： Herein we report the design of a novel sensor array based on molecularly imprinted polymer (MIP) for low-density lipoprotein (LDL) and high-density lipoprotein (HDL) determination. MIP of each lipoprotein class comprising co-monomer of methacrylic acid (MAA) and vinyl pyrrolidone (NVP) in the ratio of 3:2 and 2:3, were screened onto three-electrode quartz crystal microbalance (QCM) as selective elements toward LDL and HDL, respectively. Sensor array device reveals concentration-dependent sensor responses toward varying amount of each standard LDL and HDL solution with a linear correlation coefficient of R2 = 0.89 and 0.99, respectively. HDL-MIP presents cross-reactivity to LDL at 9-19% compared to the LDL-MIP signal. LDL-MIP also has cross-reactivity to HDL at 0-3% of LDL-MIP responses. All sensor signals are fully reversible and the sensor array can be reused.
关键词： molecularly imprinted polymers,low-density lipoprotein,high-density lipoprotein,QCM sensor array
更新于2025-09-23 15:21:01
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[Lecture Notes in Electrical Engineering] Microelectronics, Electromagnetics and Telecommunications Volume 521 (Proceedings of the Fourth ICMEET 2018) || Performance Analysis of a PV System Using HGB Converter
摘要： A photovoltaic array based system using a transformer-less high gain interleaved dc–dc boost converter is proposed in this paper. The renewable energy sources such as photovoltaic array and fuel cells provide only a time-varying and low dc voltage which cannot be directly used as the front-end for the loads or dc grid. Hence, there is a need for power electronic interfaces for matching the environmental-friendly sources of energy to the load. The interleaved converter used in the proposed system has the capability of canceling the input current ripple without increasing the component counts in the converter using a preselected duty cycle. Also, the large voltage gain and high ef?ciency of the converter are the added advantages to the proposed system. Analysis, simulation, and experimental investigation of the system proposed were carried out and the results are compared to validate the proposed system effectiveness.
关键词： Photovoltaic array,Interleaving technique,A high gain boost converter,Transformer-less dc–dc converter
更新于2025-09-23 15:21:01
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ISFET Arrays in CMOS: A Head-to-Head Comparison between Voltage and Current Mode
摘要： This paper demonstrates and compares three configurations for ISFET arrays fabricated in unmodified CMOS that facilitate chemical imaging with linear pH-to-output conversion. Specifically, the typical voltage-mode source-follower configuration is compared against our recently proposed current-mode approach using an ISFET in velocity saturation. These two topologies are also compared against an extension of the current-mode topology to include a programmable-gate capacitor inside the pixel stack for offset compensation. Various performance metrics such as linearity, speed, power consumption, size, attenuation and noise have been experimentally measured to quantify the performance of each approach and a figure-of-merit has been defined to capture the overall performance. Using this figure-of-merit the current-mode approach results in the best overall performance. Through this work however, the relative merits and limitations of each approach are identified to be used as a guide for future designs which are usually application-specific. Furthermore, we illustrate methods used to obtain standard ISFET performance metrics in order to standardize the comparison of ISFET arrays using the figure-of-merit.
关键词： CMOS,pH sensor,ISFET,voltage-mode,programmable-gate,array,current-mode
更新于2025-09-23 15:21:01
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Quantum Particle Swarm Optimization for Synthesis of Non-uniformly Spaced Linear Arrays with Broadband Frequency Invariant Pattern
摘要： This paper describes a method using Quantum Particle Swarm Optimization to obtain a broadband frequency invariant pattern for synthesis of nonuniformly spaced linear array of isotropic antennas. Two cases related to this work using QPSO have been studied, namely, in the first case, the generated frequency invariant far-field pattern is broadside in the vertical plane and in the second case, the far-field frequency invariant pattern is scanned in a particular direction. An effort is made such that the side lobe level and first null beam widths of the patterns are made similar to their related desired values. The two cases are presented in this paper to show the effectiveness of the proposed method in achieving the desired specifications. Even though, the developed method is utilized here for a linear array of isotropic antennas; it can be extended to other type of arrays. The performance of this algorithm is validated by duly comparing it with firefly algorithm.
关键词： firefly algorithm,quantum particle swarm optimization,frequency invariant pattern,side lobe level,first null beam width,Broadband array
更新于2025-09-23 15:21:01
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ELECTRICALLY RECONFIGURABLE RADIATION PATTERNS OF SLOT ANTENNA ARRAY USING AGILE PLASMA WALL
摘要： In this paper, an antenna with recon?gurable radiation pattern in the H-plane at 2.45 GHz for high power applications is presented. It is based on a 3-slot array in the E-plane covered partially with a wall of plasma in order to reduce the length of the slots and consequently ensure electrically a modi?cation of the radiation pattern in the H-plane. The power distribution of the array is ensured with a power splitter.
关键词： recon?gurable radiation pattern,high power applications,slot antenna array,plasma wall
更新于2025-09-23 15:21:01
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Fuzzy logic control for a grid-connected PV array through Z-source-inverter using maximum constant boost control method
摘要： The paper presents an alternative scheme using fuzzy logic methodology to control a grid-connected photovoltaic system through ZSI using MCBC method. The system model and control are implemented using MATLAB-SIMULINK simulation toolbox. In view of control, Fuzzy Logic Controllers (FLCs) are designed to enhance the system stability. To ensure a unity power factor operation, the inverter modulation index is controlled to manage the phase current of the grid. Also, the control in the shoot-through ratio controls the output voltage of the PV array, so the maximum power (MP) is extracted. The simulation results using FLCs are compared with others obtained using Proportional Integral (PI) controllers. This is under the same normal operating and transient conditions which are irradiation variation, three-phase short circuit fault at point of connection and voltage variation of the grid. The simulation results of FLCs achieve supplementary enhancement of the system stability over various operating conditions.
关键词： ZSI,MCBC,MP,FLC,Shoot-through,PV array
更新于2025-09-23 15:21:01
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RCS REDUCTION USING A MINIATURIZED UNI-PLANAR ELECTROMAGNETIC BAND GAP STRUCTURE FOR CIRCULARLY POLARIZED MICROSTRIP ANTENNA ARRAY
摘要： In this paper, a new method for radar cross section (RCS) reduction of circularly polarized (CP) microstrip antenna array with small element spacing is proposed. By employing the element rotation technique and loading EBG structures, the in-band and out-of-band RCSs are reduced simultaneously despite the extreme small space between array elements. The simulated results show that the proposed antenna has an average RCS reduction over 10 dB in the X-band for x-polarized and y-polarized incident waves impinging from normal direction compared to the original CP microstrip antenna array, indicating a fractional bandwidth of 40%. The maximum RCS reduction is over 25 dB. Meanwhile, the radiation performance of the proposed antenna array is kept.
关键词： RCS reduction,EBG structures,circularly polarized microstrip antenna array,element rotation technique
更新于2025-09-23 15:21:01