This paper introduces the advances of ultra-wideband （UWB） and super-wideband （SWB） planar antennas based on the printed monopole, microstrip slot and other planar antenna designs in the last decade. A brief histo...This paper introduces the advances of ultra-wideband （UWB） and super-wideband （SWB） planar antennas based on the printed monopole, microstrip slot and other planar antenna designs in the last decade. A brief history of the ultrawideband antennas is first provided. Several types of planar antennas for UWB systems with band-notched designs are reviewed. Special SWB planar antenna designs with the bandwidth ratio greater than 10：1 including metal-plate and printed monopole antennas and tapered slot antennas are presented and compared.展开更多
This paper introduces a compact dual notched UWB antenna with an independently controllable WLAN notched band integrated with fixed WiMAX band-notch.The proposed antenna utilizes a slot resonator placed in the main ra...This paper introduces a compact dual notched UWB antenna with an independently controllable WLAN notched band integrated with fixed WiMAX band-notch.The proposed antenna utilizes a slot resonator placed in the main radiator of the antenna for fixed WiMAX band notch,while an inverted L-shaped resonator in the partial ground plane for achieving frequency agility within WLAN notched band.The inverted L-shaped resonator is also loaded with fixed and variable capacitors to control and adjust the WLAN notch.The WLAN notched band can be controlled independently with a wide range of tunability without disturbing the WiMAX bandnotch performance.Step by step design approach of the proposed antenna is discussed and the corresponding mathematical analysis of the proposed resonators are provided in both cases.Simulation of the proposed antenna is performed utilizing commercially available 3D-EM simulator,Ansoft High Frequency Structure Simulator(HFSS).The proposed antenna has high selectivity with experimental validation in terms of reflection coefficient,radiation characteristics,antenna gain,and percentage radiation efficiency.The corresponding measured frequency response of the input port corresponds quite well with the calculations and simulations in both cases.The proposed antenna is advantageous and can adjust according to the device requirements and be one of the attractive candidates for overlay cognitive radio UWB applications and URLLC service in 5G tactile internet.The proposed multifunctional antenna can also be used for wireless vital signs monitoring,sensing applications,and microwave imaging techniques.展开更多
This paper presents the design of a compact bow-tie antenna with triple band notched characteristics for UWB applications. The proposed antenna can operate from 3.1 to 10.6 GHz with VSWR -...This paper presents the design of a compact bow-tie antenna with triple band notched characteristics for UWB applications. The proposed antenna can operate from 3.1 to 10.6 GHz with VSWR - 8.4 GHz) centered at 8.1 GHz, the CSRR2 rejects the WLAN band (5.15 - 5.85 GHz) centered at 5.6 GHz, and the CSRR3 rejects the band (4.10 - 4.47 GHz) centered at 4.32 GHz. Compared with recent design, this antenna is more compact, and presents better simulation results of its characteristics. Our newly designed antenna is a potential candidate for application in UWB communication systems.展开更多
The deformation behavior in Zr36 Cu64 metallic glasses with pre-introduced indent-notches has been studied by molecular dynamics simulation at the atomic scale.The indent-notches can trigger the formation of densely-p...The deformation behavior in Zr36 Cu64 metallic glasses with pre-introduced indent-notches has been studied by molecular dynamics simulation at the atomic scale.The indent-notches can trigger the formation of densely-packed clusters composed of solid-like atoms in the indent-notch affected zone.These denselypacked clusters are highly resistant to the nucleation of shear bands.Hence,there is more tendency for the shear bands to nucleate outside the indent-notch affected zone,which enlarges the deformation region and enhances both the strengthening effect and the plastic deformation ability.For indent-notched MGs,when determining the initial yielding level,there is a competition process occurring between the densely-packed clusters leading to the shear band formation outside the indent-notch affected zone and the stress-concentration localizing deformation around the notch roots.When the indent-notch depth is small,the stress-concentration around the notch root plays a dominant role,leading to the shear bands initiating from the notch root,reminiscence of the cut-notches.As the indent-notch depth increases,there are many densely-packed clusters with high resistance to deformation in the indent-notch affected zone,leading to the shear band formation from the interface between the indent-notch affected zone and the matrix.Current research findings provide a feasible means for improving the strength and the plasticity of metallic glasses at room temperature.展开更多
文摘采用加载谐振器结构,设计了一款在8 GHz处具有陷波特性的超宽带滤波器,有效地避免了X波段卫星通信系统(7.9~8.395 GHz)的连续波对超宽带通信系统的干扰。在三模谐振器的基础上加载中心加载谐振器,通过调整加载谐振器的参数对陷波频率进行调控,使得滤波器在超宽带范围内产生陷波。利用HFSS进行仿真后结果表明,该超宽带滤波器的通带在2.5~10.3 GHz,通带范围内插入损耗在0.9 d B左右,带外衰减十分陡峭。其陷波中心频率发生在8.19 GHz,在陷波频段(7.98~8.40 GHz)范围内最小插入损耗低于–7 d B,具有良好的抑制水平,整体性能表现优良。实际测试结果与仿真结果基本一致,性能指标能够达到设计要求。
基金Project supported by the National Natural Science Foundation of China （Grant No.60571053）, and the Shanghai Leading Academic Discipline Project （Grant No.T0102）.
文摘This paper introduces the advances of ultra-wideband （UWB） and super-wideband （SWB） planar antennas based on the printed monopole, microstrip slot and other planar antenna designs in the last decade. A brief history of the ultrawideband antennas is first provided. Several types of planar antennas for UWB systems with band-notched designs are reviewed. Special SWB planar antenna designs with the bandwidth ratio greater than 10：1 including metal-plate and printed monopole antennas and tapered slot antennas are presented and compared.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.2019R1A4A1023746,No.2019R1F1A1060799)the Strengthening R&D Capability Program of Sejong University.
文摘This paper introduces a compact dual notched UWB antenna with an independently controllable WLAN notched band integrated with fixed WiMAX band-notch.The proposed antenna utilizes a slot resonator placed in the main radiator of the antenna for fixed WiMAX band notch,while an inverted L-shaped resonator in the partial ground plane for achieving frequency agility within WLAN notched band.The inverted L-shaped resonator is also loaded with fixed and variable capacitors to control and adjust the WLAN notch.The WLAN notched band can be controlled independently with a wide range of tunability without disturbing the WiMAX bandnotch performance.Step by step design approach of the proposed antenna is discussed and the corresponding mathematical analysis of the proposed resonators are provided in both cases.Simulation of the proposed antenna is performed utilizing commercially available 3D-EM simulator,Ansoft High Frequency Structure Simulator(HFSS).The proposed antenna has high selectivity with experimental validation in terms of reflection coefficient,radiation characteristics,antenna gain,and percentage radiation efficiency.The corresponding measured frequency response of the input port corresponds quite well with the calculations and simulations in both cases.The proposed antenna is advantageous and can adjust according to the device requirements and be one of the attractive candidates for overlay cognitive radio UWB applications and URLLC service in 5G tactile internet.The proposed multifunctional antenna can also be used for wireless vital signs monitoring,sensing applications,and microwave imaging techniques.
文摘This paper presents the design of a compact bow-tie antenna with triple band notched characteristics for UWB applications. The proposed antenna can operate from 3.1 to 10.6 GHz with VSWR - 8.4 GHz) centered at 8.1 GHz, the CSRR2 rejects the WLAN band (5.15 - 5.85 GHz) centered at 5.6 GHz, and the CSRR3 rejects the band (4.10 - 4.47 GHz) centered at 4.32 GHz. Compared with recent design, this antenna is more compact, and presents better simulation results of its characteristics. Our newly designed antenna is a potential candidate for application in UWB communication systems.
基金supported by the National Natural Science Foundation of China under Grant 51801174the Program for the Top Young Talents of Higher Learning Institutions of Hebei under Grant BJ2018021+2 种基金the National Key R&D Program of China under Grant 2018YFA0703602the Hong Kong Scholars Program under Grant XJ2017049support from the National Science Foundation under grant number CMMI 17-026。
文摘The deformation behavior in Zr36 Cu64 metallic glasses with pre-introduced indent-notches has been studied by molecular dynamics simulation at the atomic scale.The indent-notches can trigger the formation of densely-packed clusters composed of solid-like atoms in the indent-notch affected zone.These denselypacked clusters are highly resistant to the nucleation of shear bands.Hence,there is more tendency for the shear bands to nucleate outside the indent-notch affected zone,which enlarges the deformation region and enhances both the strengthening effect and the plastic deformation ability.For indent-notched MGs,when determining the initial yielding level,there is a competition process occurring between the densely-packed clusters leading to the shear band formation outside the indent-notch affected zone and the stress-concentration localizing deformation around the notch roots.When the indent-notch depth is small,the stress-concentration around the notch root plays a dominant role,leading to the shear bands initiating from the notch root,reminiscence of the cut-notches.As the indent-notch depth increases,there are many densely-packed clusters with high resistance to deformation in the indent-notch affected zone,leading to the shear band formation from the interface between the indent-notch affected zone and the matrix.Current research findings provide a feasible means for improving the strength and the plasticity of metallic glasses at room temperature.
