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[IEEE 2018 China International SAR Symposium (CISS) - Shanghai (2018.10.10-2018.10.12)] 2018 China International SAR Symposium (CISS) - Design of Multi-Channel MMW Transmitter Module with High Isolation
摘要： This paper proposes a multi-channel millimeter wave transmitter module with high isolation between channels. For reducing its cost, one multi-layer FR4 board is used to realize the routing of DC and control signals in each channel. Power divider MMICs, capacitors, and resistors are sealed on the top metal layer of FR4. Furthermore, a Rogers 5880 board which implements the millimeter wave transmission, can obtain low insertion loss. In order to get high isolation between channels and series amplifiers, some metal iris walls are introduced to acquire better physical isolation. Electro-magnetic simulation of the cavity is demonstrated to push the resonant frequencies away from work frequency. Finally, the millimeter wave transmitter module is presented with an extremely low weight of only 41 grams by this technology, its output power greater than 35.5dBm and efficiency higher than 16 percent, respectively.
关键词： high isolation,millimeter wave,multi-channel,transmitter module
更新于2025-09-23 15:22:29
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[Methods in Molecular Biology] Immunological Tolerance Volume 1899 (Methods and Protocols) || Isolation of Human Regulatory T Lymphocytes by Fluorescence-Activated Cell Sorting
摘要： Regulatory T cells (Tregs) are a population of lymphocytes that exerts suppressive effects upon the immune system. In human peripheral blood, the major population of T lymphocytes with suppressive capacity are defined by expression of the T cell co-receptor CD4 and the interleukin-2 receptor α-chain (CD25), combined with minimal expression of the interleukin-7 receptor α subunit (CD127). We begin by outlining the method for isolating peripheral blood mononuclear cells (PBMCs) from human blood by centrifugation of whole blood overlayed on a hydrophilic polysaccharide, with an additional erythrocyte lysis step. The protocol that follows utilizes Fluorescence-Activated Cell Sorting (FACS) for the isolation of this CD4+CD25+CD127lo population of regulatory T cells, with high yield and purity, from immunostained PBMCs. Prior to FACS isolation, this protocol exploits magnetic immunoselection for pre-enrichment of CD25+ PBMC, which reduces the duration of the subsequent FACS isolation.
关键词： FACS,Fluorescence-activated cell sorting,Regulatory T cells,Cell isolation,Treg
更新于2025-09-23 15:22:29
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Apply DFT Integrated Enhanced EBAC Methodology on Defect Isolations
摘要： Design for test (DFT) has been widely applied to digital circuit failure analysis (FA) in semiconductor industries. The FA methods based on DFT involve layer-by-layer checks using a polisher and an SEM for defect identification and localization. Yet these methods have limitations with high risks of sample damages. Besides, they are highly dependent on the technical proficiencies of operators and, thus, they are not effective for precise defect isolations. This problem has been aggravated, especially at advanced nodes. The nano-probing electron beam absorbed current (EBAC) has significant advantages on precisely locating defects. This technique is to directly identify specific defects without layer-by-layer checks. Therefore, it can minimize sample damages during sample pretreatment. EBAC is an efficient technique to isolate the defects when the circuit is at the floating condition. Because the ground lines exist almost everywhere in a chip and they are for, e.g., electronic static discharge charge releases or connecting with sources for pickup, EBAC becomes a natural option for us. However, due to poor EBAC images, EBAC’s applications are restricted when the circuits under test have grounding paths. In this paper, we propose two enhanced EBAC analysis methods, based on the DFT and EBAC integrated system, for the defect isolations with grounded connections. It is the first time the DFT and EBAC integrated system is reported, and we successfully demonstrated EBAC applicability by real FA cases.
关键词： Design for test (DFT),Grounding line,Fault isolation,Electron beam absorbed current (EBAC),Failure analysis (FA)
更新于2025-09-23 15:21:21
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Compact Wideband Dual-Polarized Antenna With High Isolation Using Modified Direct Feeding Structure For Indoor Beamforming Array Applications
摘要： A modified direct feeding (MDF) structure is proposed in this paper to realize a compact (45 × 45 mm2) wideband dual-polarized antenna with high isolation (33 dB) and low cross-polarization (30 dB). Compared with the conventional crossed dipole antennas, two additional pairs of dipoles are employed as coupling baluns as well as radiators. As a consequence, the proposed antenna with more symmetrical structure has the advantages of both the direct feeding (DF) and the coupling feeding (CF) structures, such as, balanced matching, high isolation, low cross-polarization and compact size. Besides, the gap structure between adjacent dipoles is designed in elliptical shape to further improve the impedance matching. The proposed antenna realizes a wide impedance bandwidth over 51% (1.7-2.85 GHz) for VSWR < 1.5. It is worth mentioning that compact size and high isolation could greatly reduce the element spacing of beamforming antenna array. In order to investigate the performance of beamforming array, a two-element array fed by out-of-phase power divider network is developed. The lowest operating frequency can be further extended to 1.6 GHz and the cross-polarization discrimination (XPD) is more than 10 dB within ± 60° of the main lobe.
关键词： wideband,high isolation,dual-polarized.,Modified direct feeding structure,compact
更新于2025-09-23 15:21:21
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[IEEE 2018 5th IEEE International Workshop on Metrology for AeroSpace (MetroAeroSpace) - Rome, Italy (2018.6.20-2018.6.22)] 2018 5th IEEE International Workshop on Metrology for AeroSpace (MetroAeroSpace) - Active Fault Tolerant Gyromoment Control of Information Satellites and Free-flying Robots
摘要： The methods for modeling and detection of anomalous in the automatic control systems, and also practical methods for active analysis of anomalous situations, are presented. We develop algorithms for consecutive classification of onboard equipment failures and for reconfiguration of control loop. The simulation results are presented for the control systems of the information satellites and free-flying robots.
关键词： free-flying robots,gyromoment control,automatic control systems,fault detection and isolation (FDI),dynamic reliability,fault-tolerance,information satellites
更新于2025-09-23 15:21:21
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Identification of Protein Targets of Bioactive Small Molecules Using Randomly Photomodified Probes
摘要： Identifying protein targets of bioactive small molecules often requires complex, lengthy development of affinity probes. We present a method for stochastic modification of small molecules of interest with a photoactivatable phenyldiazirine linker. The resulting isomeric mixture is conjugated to a hydrophilic copolymer decorated with biotin and a fluorophore. We validated this approach using known inhibitors of several medicinally relevant enzymes. At least a portion of the stochastic derivatives retained their binding to the target, enabling target visualization, isolation, and identification. Moreover, the mix of stochastic probes could be separated into fractions and tested for binding affinity. The structure of the active probe could be determined and the probe re-synthesized to improve binding efficiency. Our approach can thus enable rapid target isolation, identification, and visualization, while providing information required for subsequent synthesis of an optimized probe.
关键词： bioactive small molecules,target isolation,protein targets,target identification,stochastic modification,target visualization,photoactivatable phenyldiazirine linker,biotin,fluorophore,hydrophilic copolymer
更新于2025-09-23 15:21:21
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Single-Layer Dual-Band Balanced Substrate- Integrated Waveguide Filtering Power Divider for 5G Millimeter-Wave Applications
摘要： A single-layer substrate-integrated waveguide (SIW) filtering power divider (FPD) with fully differential operation at 28 and 39 GHz is proposed in this letter. This FPD consists of three SIW cavities where the differential and common modes of each cavity were properly designed to form three-pole dual passbands, facilitate deployment of isolation resistors, and introduce transmission zeros while attaining high in-band common-mode rejection. To improve the output return loss and isolation in dual bands, a novel and simple approach to find the proper location of isolation resistors is presented. At operating frequencies, the measured differential-mode input or output return loss, minimum insertion loss, isolation, and common-mode suppression are >14.1 dB, <(3 + 2.2) dB, >14.9 dB, and >30.3 dB, respectively. The amplitude and phase imbalances between outputs are <0.48 dB and <4.2?, respectively.
关键词： balanced,dual-band,isolation resistor,common-mode rejection,substrate-integrated waveguide (SIW),differential,single-layer,mixed-mode,filtering power divider (FPD),5G
更新于2025-09-23 15:21:01
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Comparison Between Minimal Fluoroscopy and Conventional Approaches for Visually Guided Laser Balloon Pulmonary Vein Isolation Ablation
摘要： Introduction: Although balloon-based techniques such as the laser balloon (LB) ablation have simplified pulmonary vein isolation (PVI), procedural fluoroscopy usage remains higher in comparison to radiofrequency PVI approaches due to limited 3-dimensional mapping system integration. Methods: In this prospective study, 50 consecutive patients were randomly assigned in alternating fashion to a low fluoroscopy group (LFG, n=25) or conventional fluoroscopy group (CFG, n=25) and underwent de novo PVI procedures using visually guided LB technique. Results: There was no statistical difference in baseline characteristics or cross-overs between treatment groups. Acute PVI was accomplished in all patients. Mean follow up was 318 ± 69 days. Clinical recurrence of AF after PVI was similar between groups (CFG: 19% vs LFG: 15%; p=0.72). Total fluoroscopy time was significantly lower in the LFG than the CFG (1.7 ± 1.4 min vs. 16.9 ± 5.9 min; p < 0.001) despite similar total procedure duration (143 ± 22 min vs. 148 ± 22 min; p= 0.42) and mean LA dwell time (63 ± 15 min vs. 59 ± 10 min; p=0.28). Mean DAP was significantly lower in the LFG (181 ± 125 μGym2 vs. 1980 ± 750 μGym2; p < 0.001). Fluoroscopy usage after transseptal access was substantially lower in the LFG (0.63 ± 0.43 min vs. 11.70 ± 4.32 min; p < 0.001). Complications rates were similar between both groups (4% vs. 2%; p=0.57). Conclusions: This study demonstrates that LB PVI can be safely achieved using a novel low fluoroscopy protocol while also substantially reducing fluoroscopy usage and radiation exposure in comparison to conventional approaches for LB ablation.
关键词： Atrial fibrillation,laser balloon,low fluoroscopy,fluoroless,pulmonary vein isolation,laser ablation
更新于2025-09-23 15:21:01
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Optical isolation by hot atoms
摘要： A collection of hot rubidium atoms is shown to exhibit non-reciprocal optical transmission due to the interplay between thermal motion and electromagnetically induced transparency.
关键词： electromagnetically induced transparency,non-reciprocal optical transmission,optical isolation,hot atoms
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 26th International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA) - Hangzhou, China (2019.7.2-2019.7.5)] 2019 IEEE 26th International Symposium on Physical and Failure Analysis of Integrated Circuits (IPFA) - Practical Dynamic Laser Stimulation Technique and Code Modification: A Soft Defect Localization Approach for Microcontroller Self-Test Failures
摘要： A practical alternative for soft defect localization (SDL) and fault isolation of dynamic failures is presented. The approach utilizes an existing optical beam induced resistance change (OBIRCH) hardware without a dynamic laser stimulation (DLS) add-on kit, coupled with an exhaustive electrical sample prep step which involves code modification. The technique was proven effective in localizing failures pertaining to resistive interconnects which are rather difficult to analyze using conventional static techniques.
关键词： Self-test code,Fault isolation,Soft-defect localization,Dynamic failures,Dynamic laser stimulation
更新于2025-09-23 15:19:57