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5G Wideband Bandpass Filtering Power Amplifiers Based on a Bandwidth-Extended Bandpass Matching Network

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China Communications 2023年第11期20卷 56-66页

作者： Weimin Wang Hongmin Zhao yongle wu Xiaopan Chen School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China School of Integrated Circuits Beijing University of Posts and TelecommunicationsBeijing 100876China

In this paper,a 5G wideband power amplifier(PA)with bandpass filtering response is synthesized using a bandwidth-extended bandpass filter as the matching network(MN).In this structure,the bandwidth(θ_(C))is defined as a variable in the closedform equations provided by the microstrip bandpass *** can be extended over a wide range only by changing the characteristic impedances of the *** from the other wideband MNs,the extension of bandwidth does not increase the complexity of the structure(order n is fixed).In addition,based on the bandwidth-extended structure,the wideband design of bandpass filtering PA is not limited to the fixed bandwidth of the specific filter *** theoretical analysis of the MN and the design flow of the PA are provided in this *** fabricated bandpass filtering PA can support almost one-octave bandwidth(2-3.8 GHz),covering the two 5G bands(n41 and n78).The drain efficiency of 47%-60%and output power higher than 40 dBm are *** frequency selectivity in S-parameter measurements can be observed.

关键词： bandpass filtering bandwidth-extension fixed order power amplifier wideband

Creating Distinctive Connections between Multifunctional Microwave Circuits and Mobile-Terminal Radio-Frequency Integrated Chips Using Integrated Passive Device Technology

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China Communications 2021年第8期18卷 121-132页

作者： yongle wu Mengdan Kong Zheng Zhuang Weimin Wang School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

In this review,the advanced microwave devices based on the integrated passive device(IPD)technology are expounded and discussed in detail,involving the performance breakthroughs and circuit ***,the development trend of IPD-based multifunctional microwave circuits is predicted further by analyzing the current research hot *** paper discusses a distinctive research area for microwave circuits and mobile-terminal radio-frequency integrated chips.

关键词： chips integrated passive device(IPD) multifunctional microwave circuit

The Art of Power Dividing:A Review for State-of-the-Art Planar Power Dividers

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China Communications 2017年第5期14卷 1-16页

作者： yongle wu Lingxiao Jiao Zheng Zhuang Yuanan Liu School of Electronic Engineering Beijing Key Laboratory of Work Safety Intelligent MonitoringBeijing University of Posts and TelecommunicationsBeijing 100876China

In this paper,massive state-of-theart planar power dividers are presented and discussed. The innovations of these superiorly-performanced power dividers lie in the performance breakthrough,physical configurations and function integrations. Eventually,based on the trend presented,the future of the power dividers is predicted. This paper might have inspiration significance to illuminate the way for the development of power dividers.

关键词： power divider microwave circuit microwave passive component analog circuit

Planar Compact Dual-Band Coupled-Line Balun with High Isolation

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China Communications 2017年第2期14卷 40-48页

作者： Weiwei Zhang yongle wu Weimin Wang Xiaochuan Shen Beijing Key Laboratory of Work Safety Intelligent Monitoring School of Electronic EngineeringBeijing University of Posts and Telecommunications Beijing 100876 China

A planar circuit structure, which is based on three cascaded pairs of coupled lines, an open stub, and an isolation resistor, is proposed in this paper to design a compact *** balun with high isolation. This circuit features equal power division with out of phase, all ports matching, high isolation between two outputs, compact structure, and inherent impedance transformation. The closedform design equations are derived based on the traditional *** theory and even.(odd.) mode analysis. A practical *** balun, which operates at 0.9/1.8GHz, is designed and fabricated to validate the function of equal power division with out of phase and high isolation between two outputs. The consistency between the simulated and measured results verify the design theory.

关键词： balun dual band coupled line high isolation

Engineering nanoporous and solid core-shell architectures of lowplatinum alloy catalysts for high power density PEM fuel cells

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Nano Research 2022年第7期15卷 6148-6155页

作者： Yongqiang Kang Jiaqi Wang Yinping Wei yongle wu Dongsheng Xia Lin Gan Institute of Materials Research Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China

Low-platinum(Pt)alloy catalysts hold promising application in oxygen reduction reaction(ORR)electrocatalysis of protonexchange-membrane fuel cells(PEMFCs).Although significant progress has been made to boost the kinetic ORR mass activity at low current densities in liquid half-cells,little attention was paid to the performance of Pt-based catalysts in realistic PEMFCs particularly at high current densities for high power density,which remains poorly *** this paper,we show that,regardless of the kinetic mass activity at the low current density region,the high current density performance of the low-Pt alloy catalysts is dominantly controlled by the total Pt surface area,particularly in low-Pt-loading H_(2)–air *** this end,we propose two different strategies to boost the specific Pt surface area,the post-15-nm dealloyed nanoporous architecture and the sub-5-nm solid core–shell nanoparticles(NPs)through fluidic-bed synthesis,both of which bring in comparably high mass activity and high Pt surface area for large-current-density *** medium current density,the dealloyed porous NPs provide substantially higher H_(2)–air PEMFC performance compared to solid core–shell catalysts,despite their similar mass activity in liquid *** transmission electron microscopy images combined with electron energy loss spectroscopic imaging evidence a previously unreported“semi-immersed nanoporous-Pt/ionomer”structure in contrast to a“fully-immersed core–shellPt/ionomer”structure,thus favoring O_(2) transport and improving the fuel cell *** results provide new insights into the role of Pt nanostructures in concurrently optimizing the mass activity,Pt surface area and Pt/Nafion interface for high power density fuel cells.

关键词： low-platinum alloy catalyst nanoporosity proton-exchange-membrane fuel cells power density triple-phase boundary

Single-Layer Symmetrical Full-Port Quasi-Absorptive Filtering Phase Shifter

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China Communications 2023年第12期20卷 30-40页

作者： Qingxiang Dong yongle wu Weijuan Chen Yuhao Yang Weimin Wang School of Integrated Circuits Beijing University of Posts and TelecommunicationsBeijing 100876China School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

In this article,a single-layer symmetrical full-port quasi-absorptive filtering phase shifter is *** proposed phase shifter is composed of a main quasi-absorptive filtering branch,a reference quasi-absorptive filtering branch,and two delay *** proposed phase shifter achieves both phase controlling function and quasi-absorptive filtering function for the first *** quasi-absorptive filtering branch can realize the quasi-absorptive filtering ***,the constant phase shift can be obtained by combining the two quasi-absorptive filtering branches and the two delay *** design formulas can be derived from the even-and odd-mode network analysis,and then two quasi-absorptive filtering phase shifters can be devised easily and *** verification,a 90°quasi-absorptive filtering phase shifter,which is critical for circularly polarized antenna systems,is simulated,manufactured,and measured.

关键词： filtering phase shifter(PS) quasiabsorptive reflectionless symmetrical

Novel physical probe configurations in a multi-probe based 3D MIMO OTA setup

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The Journal of China Universities of Posts and Telecommunications 2017年第1期24卷 60-66页

作者： Wang Weimin Li Muyuan Liu Yuan'an wu yongle Li Shulan Beijing Key Laboratory of Work Safety Intelligent Monitoring Beijing University of Posts and Telecommunications Beijing 100876 China School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

In this paper, channel spatial characteristics which mainly depend on the spatial correlation are selected as the significant factors in over-the-air （OTA） testing for multiple input multiple output （MIMO） devices. The multi-probe anechoic chamber method, a promising candidate of the MIMO OTA testing methods, can reproduce the multipath environments in a controllable manner. A novel physical configuration based on the variation of relative positions of probes in a MIMO OTA setup is put forward to obtain better spatial characteristics. Two physical configurations are presented to make a comparison with the typical configuration in this paper. The simulation results show that by making a proper probe configuration, good channel simulation accuracy can be achieved. Meanwhile, in order to get better performance of emulating channel spatial characteristics, probes in the first and the last probe rings should be placed symmetrically in three dimensional （3D） physical probe configuration.

关键词： MIMO OTA channel spatial characteristics multi-probe anechoic chamber physical configuration

Dual-Band Coupled-Line Bandpass Filter with Independently Tunable Bandwidths

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China Communications 2016年第9期13卷 60-64页

作者： yongle wu Lixia Nan Lingxiao Jiao Weimin Wang Yuanan Liu Beijing Key Laboratory of Work Safety Intelligent Monitoring School of Electronic EngineeringBeijing University of Posts and Telecommunications

This paper reports a novel dual-band coupled-line bandpass *** a quadruple-mode coupled-line resonator,this proposed filter could filter signals on two frequency *** introducing two varactors,one of the four resonances could be continuously altered by changing the capacitance of the varactors,thus the two frequency bandwidths could be independently *** this paper,the detailed explanation for its operation is given,and the agreement between the expected and practical performance sufficiently confirms the robustness and effectiveness of this proposed filter.

关键词： filters tunable dual band coupled line

Standardization of tritiated water by the CIEMAT/NIST and TDCR methods

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Science China(Technological Sciences) 2015年第3期58卷 559-564页

作者： wu yongle LIU HaoRan LIANG JunCheng LIU JiaCheng XIONG WenJun YUE HuiGuo LIU SenLin YANG YuanDi YUAN DaQing China Institute of Atomic Energy Nuclear and Radiation Safety Center National Institute of Metrology

The activity of tritiated water has been standardized by two liquid scintillation counting methods:The CIEMAT/NIST method with the54Mn-standard efficiency tracing and the triple-to-double coincidence ratio(TDCR)*** samples were prepared with Ultima Gold TM AB liquid scintillation cocktail in low-potassium glass *** the application of the CIEMAT/NIST method,the computer program EMILIA was used to calculate the efficiency of3H and54Mn according to the KL1L2L3M atomic rearrangement *** the detection efficiency of the TDCR counter was calculated using TDCR07 code,which makes it possible to allow for the potential asymmetry between the three photomultiplier *** influence of stopping power and k B factor is discussed in the *** a power approach is adopted for the stopping power for electrons below 1ke V and k B is chosen to be 0.0075 cm/Me V,the relative deviation will be only 0.3%between the two methods.

关键词： tritiated water the CIEMAT/NIST method the TDCR method k B factor the stopping power liquid scintillation counting