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oe1(光电查) - 科学论文

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出版时间
  • 2018
研究主题
  • filtering responses
  • compact size
  • substrate integrated waveguide (SIW)
  • Balun and balanced circuits
应用领域
  • Electronic Science and Technology
机构单位
  • South China University of Technology
41 条数据
?? 中文（中国） ▾

  • [IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Thermal Noise Metrology with Time-Based Synthesis

    摘要： We present a new measurement technique for quantifying noise temperature based on temperature and time. A single-pole, double-throw (SPDT) ultra-fast switch combines signals from outputs of two synchronized electromechanical (EM) switches. The input ports of EM switches are terminated by one unknown noise source, one known cold noise source, and two known noise references at ambient temperature. The magnitude of the combined noise signal can be adjusted by the duty cycle of the transistor-transistor logic (TTL) pulse that controls the fast switch. The measurement approaches the balanced mode by regulating the TTL duty cycle in order to minimize the difference between the combined noise signal and the ambient noise reference. In comparison to conventional total-power radiometers, this new instrumentation is more efficient and potentially provides a wider dynamic range.

    关键词： thermal noise,feed-back loop,Balanced radiometer,noise synthesis,switch

    更新于2025-09-10 09:29:36

  • Wideband balun filter on slot-line resonator with intrinsic balanced performance in magnitude and phase

    摘要： In this article, a novel wideband balun filter on the coupled slotline-line resonator topology with intrinsic balanced performance in magnitude and phase performance is presented. The proposed wideband balun filter consists of four uniform half-wavelength slot-line resonators (SLRs) in middle, one single-ended unbalanced port, and one balanced port with two terminals. By utilizing the distinct field conversion from the slotline to the microstrip line feeding line, the proposed technique can realize good balanced performance inherently in magnitude and phase over a wideband frequency range. In order to demonstrate the proposed scheme and support the design conception, one circuit prototype is designed, fabricated, and tested. All of the measured results of the frequency response, magnitude, and phase imbalance performance agree well with the simulated one, and these results have effectively demonstrated its good filtering property, intrinsic balanced performance in magnitude and phase over a wide band frequency.

    关键词： slotline resonator (SLR),phase imbalance,magnitude imbalanced,balun filter,balanced performance,wideband

    更新于2025-09-10 09:29:36

  • Improved dual-mode compressive tracking integrating balanced colour and texture features

    摘要： Discriminative tracking methods can achieve state-of-the-art performance by considering tracking as a classification problem tackled with both object and background information. As a high efficient discriminative tracker, compressive tracking (CT) has attracted much attention recently. However, it may easily fail when the object suffers from long-term occlusions, and severe appearance and illumination changes. To address these issues, the authors develop a robust tracking framework based on CT by considering balanced feature representation as well as dual-mode classifier construction. First, the original measurement matrix of CT works as a dominated texture feature extractor. To obtain a balanced feature representation, they propose to induce a complementary measurement matrix by considering both texture and colour features. Then, they develop two classifiers (dual mode) by using previous and current sample sets, respectively, and subsequently combine them into one ensemble classifier to track the target, which can help to avoid tracking failure suffering from severe appearance changes and long term occlusion. Moreover, they propose a classifier updating schema to prevent the inclusion of unsatisfied positive samples by predicting the occlusions with their ensemble classifier. The extensive experiments demonstrate the superior performance of their tracking framework under various situations.

    关键词： dual-mode classifier,balanced feature representation,occlusion detection,compressive tracking

    更新于2025-09-10 09:29:36

  • GaAs MMIC Low Noise Amplifier With Integrated High-Power Absorptive Receive Protection Switch

    摘要： This letter reports a GaAs monolithic microwave integrated circuit (MMIC) low noise amplifier (LNA) with integrated high-power absorptive receive protection switch realized using 0.13-μm GaAs pHEMT process. On-the-chip current distributed, resonant shunt FET switch configuration is employed for higher power handling. FET stacking technique is used to reduce the effective noise figure (NF). A two-stage LNA with integrated high power switch, forming each arm in a balanced configuration is employed to realize a monolithic LNA with integrated absorptive receive protection switch. This novel MMIC provides protection up to 20-W continuous wave and 2.9-dB NF, a gain of 20 dB over 9.3–9.9 GHz.

    关键词： MMIC,integrated circuit,receive,current distribution,protection switch,monolithic microwave,Balanced configuration

    更新于2025-09-09 09:28:46

  • Novel Reconfigurable Single-to-Balanced, Power-Dividing, and Single-Ended Filter With Frequency and Bandwidth Control

    摘要： In this paper, a novel tunable ?lter with recon?gurable single-to-balanced (SE-BAL), power dividing (PD), and single-to-single-ended (SE) ?ltering functionalities is proposed, for the ?rst time, without any additional switching circuit. The proposed ?lter only consists of three stepped-impedance resonators, which are loaded and connected by varactors in between. With a very simple and compact con?guration, the proposed ?lter achieves multiple recon?gurable functionalities between SE-BAL ?ltering, PD ?ltering, and conventional SE bandpass ?ltering. Moreover, the recon?gurable SE-BAL, PD, and SE bandpass ?lter can not only offer continuously frequency tuning over a wide tuning range but also have independent bandwidth tuning and maintain good phase/amplitude balance in each tuning state. The proposed ?lter is designed and fabricated with the microstrip line technology; the measured results show that the SE-BAL, PD, and SE ?ltering functions can be continuously tuned from 1.02 to 1.32, 0.96 to 1.27, and 1 to 1.28 GHz, with 1-dB bandwidth tuning from 30 to 60, 30 to 110, and 70 to 130 MHz, respectively. The amplitude and phase imbalances of the SE-BAL and PD bandpass ?lter are less than 0.4 dB, 1.3° and 0.5 dB, 1.5°, respectively, in the passband of each tuning state. Good agreement was obtained between simulated and measured results.

    关键词： single-ended (SE) ?lter,single-to-balanced (SE-BAL) ?lter,recon?gurable ?lter,Filtering power divider (FPD)

    更新于2025-09-09 09:28:46

  • Separability of multi-qubit states in terms of diagonal and anti-diagonal entries

    摘要： We give separability criteria for general multi-qubit states in terms of diagonal and anti-diagonal entries. We de?ne two numbers which are obtained from diagonal and anti-diagonal entries, respectively, and compare them to get criteria. They give rise to characterizations of separability when all the entries are zero except for diagonal and anti-diagonal, like Greenberger–Horne–Zeilinger diagonal states. The criteria are strong enough to detect nonzero volume of entanglement with positive partial transposes.

    关键词： Separability criterion,Phase difference,Irreducible balanced multisets,Phase identities,Multi-qubit states,X-states

    更新于2025-09-09 09:28:46

  • Ultra-low Noise Balanced Detectors for Optical Time Domain Measurements

    摘要： Two ultra-low noise balanced detectors used for optical time domain measurements are presented in this paper. Both simultaneously achieve high bandwidth and low noise that is extremely difficult to realize in commercial detectors. Two-stage amplification circuits based on transimpedance amplifiers (TIAs) were used for these detectors, with special modifications implemented for different applications. To further suppress noise, a low noise junction field effect transistor (JFET) is connected between the photodiode and TIA to reduce the impact of amplifier leakage current in one of the detectors. Benefiting from this design, a 70 MHz sensitive detector with a gain of 3.2E5 V/W and low noise equivalent power density (NEP) of 2.2 pW/rtHz was implemented. For another balanced detector used in higher bandwidth applications, the differential transimpedance amplifier circuit is used, with the detector achieving a 250 MHz bandwidth with a gain of 5E4 V/W, equivalent to NEP of 6.2 pW/rtHz. Due to the difficulty of achieving high bandwidth with low noise, we perform theoretical analysis and simulations for our designs to ensure that these two design goals are realized simultaneously. The performance of the detectors is consistent with our analysis. In addition, a simplified optical testing system was built to test and calculate the performance of the detectors in their respective applications. The results show that both detectors are well balanced and achieve a common mode rejection ratio (CMRR) greater than 50 dB.

    关键词： Balanced detectors,optoelectronic devices,time domain measurements,circuit simulations,noise measurements

    更新于2025-09-09 09:28:46

  • Compact Balanced Single-Band and Dual-Band BPFs with Controllable Bandwidth Using FoldedS-Shaped Slotline Resonators (FSSRs)

    摘要： In this paper, two compact balanced bandpass filters (BPFs) using half-wavelength folded S-shaped slotline resonators (FSSRs) are designed. The proposed FSSR is realized by extending and folding a traditional S-shaped slotline resonator, which can affect the internal coupling of resonator and reduce the size of the resonator. The balanced stepped-impedance microstrip-slotline transition structures are employed to generate a wideband common-mode (CM) suppression. The proposed filters can realize a single-band differential-mode (DM) bandpass response or a dual-band one by employing one or three FSSRs, respectively. Moreover, the center frequencies of the DM passbands are independent from the CM responses, which can simplify the designs procedure significantly. In order to validate their practicability, a compact balanced dual-band BPF with controllable center frequencies and bandwidths is fabricated and good agreement between the simulated and measured results is observed.

    关键词： S-shaped slotline resonators (FSSRs),balanced bandpass filters (BPFs),folded,dual-band

    更新于2025-09-04 15:30:14

  • IMPROVEMENT OF RADIATION CHARACTERISTICS OF BALANCED ANTIPODAL VIVALDI ANTENNA USING TRASFORMATION OPTICS

    摘要： Transformation optics is a convenient method to control paths of electromagnetic waves and radiation characteristics of antennas. In this paper, we try to increase the gain of Balanced Antipodal Vivaldi Antenna (BAVA) over 8{16 GHz frequency band using an optical conformal transformation. The proposed antenna can be implemented by ordinary dielectric materials and graded photonic crystals (GPCs). In this designed BAVA, better side-lobe level (SLL) and cross-polarization are achieved compared to a conventional BAVA. Simulation results validate the performance of the design approach.

    关键词： graded photonic crystals,Transformation optics,Balanced Antipodal Vivaldi Antenna,cross-polarization,side-lobe level,gain improvement

    更新于2025-09-04 15:30:14

  • [IEEE 2018 13th European Microwave Integrated Circuits Conference (EuMIC) - Madrid, Spain (2018.9.23-2018.9.25)] 2018 13th European Microwave Integrated Circuits Conference (EuMIC) - GaAs Balanced Amplifier for Ka-Band Space Communications System

    摘要： The paper deals with the development of a state-of-the-art medium level amplifier able to combine good noise performance with a high P1dB compression point. The MMIC is realized with a balanced structure and making use of the PH25 GaAs pHEMT process provided by UMS. The balanced structure allows to achieve a gain of 19 dB with a P1dB compression point greater than 15 dBm and a noise figure of about 3 dB in a large bandwidth spanning from 26.5 GHz to 31.5 GHz. The chip has a single bias pad; the input and output bond wires are directly matched on chip, so easingenhancing the mechanical integration in the front-end.

    关键词： Ka-band,GaAs technology,Balanced amplifier,Space technology,dynamic range

    更新于2025-09-04 15:30:14