The vortex-induced vibrations （VIV） of barrel-shaped mast are calculated by three numerical metods, i.e. New- mark- β, HPD-L （High Precision Direct integration scheme-Linear form）, and HPD-S （High Precision Dire...The vortex-induced vibrations （VIV） of barrel-shaped mast are calculated by three numerical metods, i.e. New- mark- β, HPD-L （High Precision Direct integration scheme-Linear form）, and HPD-S （High Precision Direct integration scheme-Sinusoidal form）. According to the measured value, the accuracy curves are given to show the advantages of HPD-S method over others. Based on the comparison above, HPD-S method is used to calculate the influence of ice covering on the mast to VIV responses. It has been proved that the vortex-induced responses of barrel-shaped mast are changed along with ice thicknesses and types.展开更多
In this article,a single-layer symmetrical full-port quasi-absorptive filtering phase shifter is presented.The proposed phase shifter is composed of a main quasi-absorptive filtering branch,a reference quasi-absorptiv...In this article,a single-layer symmetrical full-port quasi-absorptive filtering phase shifter is presented.The proposed phase shifter is composed of a main quasi-absorptive filtering branch,a reference quasi-absorptive filtering branch,and two delay lines.The proposed phase shifter achieves both phase controlling function and quasi-absorptive filtering function for the first time.Each quasi-absorptive filtering branch can realize the quasi-absorptive filtering function.Meanwhile,the constant phase shift can be obtained by combining the two quasi-absorptive filtering branches and the two delay lines.The 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 quickly.For verification,a 90°quasi-absorptive filtering phase shifter,which is critical for circularly polarized antenna systems,is simulated,manufactured,and measured.展开更多
This paper considers a high energy efficiency dynamic connected(HEDC)structure,which promotes the practicability and reduces the power consumption of hybrid precoding system by lowresolution phase shifters(PSs).Based ...This paper considers a high energy efficiency dynamic connected(HEDC)structure,which promotes the practicability and reduces the power consumption of hybrid precoding system by lowresolution phase shifters(PSs).Based on the proposed structure,a new hybrid precoding algorithm is presented to optimize the energy efficiency,namely,HP-HEDC algorithm.Firstly,via a new defined effective optimal precoding matrix,the problem of optimizing the analog switch precoding matrix is formulated as a sparse representation problem.Thus,the optimal analog switch precoding matrix can be readily obtained by the branch-and-bound method.Then,the digital precoding matrix optimization problem is modeled as a dictionary update problem and solved by the method of optimal direction(MOD).Finally,the diagonal entries of the analog PS precoding matrix are optimized by exhaustive search independently since PS and antenna is one-to-one.Simulation results show that the HEDC structure enjoys low power consumption and satisfactory spectral efficiency.The proposed algorithm presents at least 50%energy efficiency improvement compared with other algorithms when the PS resolution is set as 3-bit.展开更多
This paper presents a systematic investigation and demonstration of a K-band circularly polarized liquidcrystal-based phased array(LCPA),including the design,over-the-air(OTA)in-array calibration,and experimental vali...This paper presents a systematic investigation and demonstration of a K-band circularly polarized liquidcrystal-based phased array(LCPA),including the design,over-the-air(OTA)in-array calibration,and experimental validation.The LCPA contains 16 phase-shifting radiating channels,each consisting of a circularly polarized stacked patch antenna and a liquid-crystal-based phase shifter(LCPS)based on a loaded differential line structure.Thanks to its slow-wave properties,the LCPS exhibits a maximum phase-shifting range of more than 360°with a figure of merit of 78.3(°)·dB^(-1)based on a liquid crystal layer with a thickness of only 5μm.Furthermore,an automatic OTA calibration based on a state ergodic method is proposed,which enables the extraction of the phase-voltage curve of every individual LCPA channel.The proposed LCPA is manufactured and characterized with a total profile of only 1.76 mm,experimentally demonstrating a scanned circularly polarized beam from-40°to+40°with a measured peak gain of 12.5 dBic and a scanning loss of less than 2.5 dB.The bandwidth of the LCPA,which satisfies the require-ments of port reflection(|S_(11)|)<-15 dB,an axial ratio(AR)<3 dB,beam squinting<3°,and a gain variation<2.2 dB,spans from 25.5 to 26.0 GHz.The total efficiency is about 34%,which represents a new state of the art.The use of the demonstrated low-profile LCPA to support circularly polarized scanning beams,along with the systematic design and calibration methodology,holds potential promise for a variety of millimeter-wave applications.展开更多
基于130 nm双极型晶体管与互补金属氧化物半导体(Bipolar and Complementary Metal Oxide Semiconductor,BiCMOS)工艺,采用矢量合成架构的高精度移相器架构,提出了一款满足5G与民用卫星通信应用需求的K频段4通道高精度有源移相器。在移...基于130 nm双极型晶体管与互补金属氧化物半导体(Bipolar and Complementary Metal Oxide Semiconductor,BiCMOS)工艺,采用矢量合成架构的高精度移相器架构,提出了一款满足5G与民用卫星通信应用需求的K频段4通道高精度有源移相器。在移相器输入端和输出端,为了实现单端信号与差分信号的互相转换,同时为信号链路提供一定的增益,采用了有源巴伦结构。为了以更小的芯片面积实现差分信号到4路I/Q正交信号的转换,采用了折叠朗格耦合器;为了实现高精度的相位调节控制,采用了有源矢量合成器。芯片实测结果表明,在18~22 GHz的带宽内,各通道小信号增益在-3~-2 dB之间,增益平坦度小于1 dB,在-45℃~85℃之间增益波动小于3.5 dB,6位移相器移相误差均方根(Root Mean Square,RMS)小于2.5°。芯片尺寸为2.68 mm×2.5 mm。展开更多
文摘The vortex-induced vibrations （VIV） of barrel-shaped mast are calculated by three numerical metods, i.e. New- mark- β, HPD-L （High Precision Direct integration scheme-Linear form）, and HPD-S （High Precision Direct integration scheme-Sinusoidal form）. According to the measured value, the accuracy curves are given to show the advantages of HPD-S method over others. Based on the comparison above, HPD-S method is used to calculate the influence of ice covering on the mast to VIV responses. It has been proved that the vortex-induced responses of barrel-shaped mast are changed along with ice thicknesses and types.
基金supported by National Natural Science Foundations of China(No.U20A20203,No.61971052,U21A20510)the Fundamental Research Funds for the Central Universities(2021XDA07-1)Key Research and Development Project of Guangdong Province(2020B0101080001)。
文摘In this article,a single-layer symmetrical full-port quasi-absorptive filtering phase shifter is presented.The proposed phase shifter is composed of a main quasi-absorptive filtering branch,a reference quasi-absorptive filtering branch,and two delay lines.The proposed phase shifter achieves both phase controlling function and quasi-absorptive filtering function for the first time.Each quasi-absorptive filtering branch can realize the quasi-absorptive filtering function.Meanwhile,the constant phase shift can be obtained by combining the two quasi-absorptive filtering branches and the two delay lines.The 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 quickly.For verification,a 90°quasi-absorptive filtering phase shifter,which is critical for circularly polarized antenna systems,is simulated,manufactured,and measured.
基金supported by the National Natural Science Foundation of China(Grant No.61971117)the Natural Science Foundation of Hebei Province(Grant No.F2020501007)the S&T Program of Hebei(No.22377717D)。
文摘This paper considers a high energy efficiency dynamic connected(HEDC)structure,which promotes the practicability and reduces the power consumption of hybrid precoding system by lowresolution phase shifters(PSs).Based on the proposed structure,a new hybrid precoding algorithm is presented to optimize the energy efficiency,namely,HP-HEDC algorithm.Firstly,via a new defined effective optimal precoding matrix,the problem of optimizing the analog switch precoding matrix is formulated as a sparse representation problem.Thus,the optimal analog switch precoding matrix can be readily obtained by the branch-and-bound method.Then,the digital precoding matrix optimization problem is modeled as a dictionary update problem and solved by the method of optimal direction(MOD).Finally,the diagonal entries of the analog PS precoding matrix are optimized by exhaustive search independently since PS and antenna is one-to-one.Simulation results show that the HEDC structure enjoys low power consumption and satisfactory spectral efficiency.The proposed algorithm presents at least 50%energy efficiency improvement compared with other algorithms when the PS resolution is set as 3-bit.
基金supported in part by the National Natural Science Foundation of China(NSFC62122019 and 62293492)+2 种基金the National Key Research and Development Program of China(2019YFB2204704)the Fundamental Research Funds for the Central Universitiesthe Zhishan Scholar Program of Southeast University(2242022R40038).
文摘This paper presents a systematic investigation and demonstration of a K-band circularly polarized liquidcrystal-based phased array(LCPA),including the design,over-the-air(OTA)in-array calibration,and experimental validation.The LCPA contains 16 phase-shifting radiating channels,each consisting of a circularly polarized stacked patch antenna and a liquid-crystal-based phase shifter(LCPS)based on a loaded differential line structure.Thanks to its slow-wave properties,the LCPS exhibits a maximum phase-shifting range of more than 360°with a figure of merit of 78.3(°)·dB^(-1)based on a liquid crystal layer with a thickness of only 5μm.Furthermore,an automatic OTA calibration based on a state ergodic method is proposed,which enables the extraction of the phase-voltage curve of every individual LCPA channel.The proposed LCPA is manufactured and characterized with a total profile of only 1.76 mm,experimentally demonstrating a scanned circularly polarized beam from-40°to+40°with a measured peak gain of 12.5 dBic and a scanning loss of less than 2.5 dB.The bandwidth of the LCPA,which satisfies the require-ments of port reflection(|S_(11)|)<-15 dB,an axial ratio(AR)<3 dB,beam squinting<3°,and a gain variation<2.2 dB,spans from 25.5 to 26.0 GHz.The total efficiency is about 34%,which represents a new state of the art.The use of the demonstrated low-profile LCPA to support circularly polarized scanning beams,along with the systematic design and calibration methodology,holds potential promise for a variety of millimeter-wave applications.
文摘基于130 nm双极型晶体管与互补金属氧化物半导体(Bipolar and Complementary Metal Oxide Semiconductor,BiCMOS)工艺,采用矢量合成架构的高精度移相器架构,提出了一款满足5G与民用卫星通信应用需求的K频段4通道高精度有源移相器。在移相器输入端和输出端,为了实现单端信号与差分信号的互相转换,同时为信号链路提供一定的增益,采用了有源巴伦结构。为了以更小的芯片面积实现差分信号到4路I/Q正交信号的转换,采用了折叠朗格耦合器;为了实现高精度的相位调节控制,采用了有源矢量合成器。芯片实测结果表明,在18~22 GHz的带宽内,各通道小信号增益在-3~-2 dB之间,增益平坦度小于1 dB,在-45℃~85℃之间增益波动小于3.5 dB,6位移相器移相误差均方根(Root Mean Square,RMS)小于2.5°。芯片尺寸为2.68 mm×2.5 mm。
