We report on the investigation of optimal bias region of a wide-band superconducting hot electron bolometer(HEB)mixer in terms of noise temperature performance for multi-pixel heterodyne receiver application in the 5-...We report on the investigation of optimal bias region of a wide-band superconducting hot electron bolometer(HEB)mixer in terms of noise temperature performance for multi-pixel heterodyne receiver application in the 5-meter Dome A Terahertz Explorer(DATE5)telescope.By evaluating the double sideband(DSB)receiver noise temperature(Trec)across a wide frequency range from 0.2 THz to 1.34 THz and with a large number of bias points,a broad optimal bias region has been observed,illustrating a good bias applicability for multipixel application since the performance of the HEB mixer is uniquely determined by each bias point.The noise temperature of the HEB mixer has been analyzed by calibrating the noise contribution of all RF components,whose transmissions have been measured by a time-domain spectroscopy.The corrected noise temperature distribution shows a frequency independence relation.The dependence of the optimal bias region on the bath temperature of the HEB mixer has also been investigated,the bath temperature has limited effect on the lowest receiver noise temperature until 7 K,however the optimal bias region deteriorates obviously with increasing bath temperature.展开更多
超导HEB(Hot Electron Bolometer)热电子混频器是1THz以上灵敏度最高的相干探测器,为了进一步提高其灵敏度,有效减小射频信号在传输路径中的损耗,实现超导HEB混频器的超宽带混频功能,设计高耦合效率的射频匹配电路尤为重要。首先提出了...超导HEB(Hot Electron Bolometer)热电子混频器是1THz以上灵敏度最高的相干探测器,为了进一步提高其灵敏度,有效减小射频信号在传输路径中的损耗,实现超导HEB混频器的超宽带混频功能,设计高耦合效率的射频匹配电路尤为重要。首先提出了混频器耦合电路的理论模型,然后采用三维电磁场仿真软件HFSS和类似于准光学天线的集总源法,设计了一种超宽带、低损耗的太赫兹信号耦合电路,对超导HEB混频器的嵌入阻抗在整个0.9～1.3THz的工作频带范围内进行了详细的分析。系统研究了低通滤波器中高低阻抗线结构,波导到微带转换中存在的高次模对射频信号传输的影响,并模拟仿真了实验中可能出现的磨片厚度误差对嵌入阻抗的影响。分析结果表明,该混频器的嵌入阻抗为35Ω-j10Ω左右,在整个工作频带内变化缓慢,能够实现超宽频带匹配,混频器的相对工作带宽可达到36%,仿真结果和理论模型计算结果完全一致。该研究结果对研制超宽带高灵敏度的超导HEB混频器具有很好的指导意义。展开更多
基金Project supported by the Chinese Academy of Sciences(Grant Nos.GJJSTD20180003 and QYZDJ-SSW-SLH043)the National Key Basic Research and Development Program of China(Grant Nos.2017YFA0304003 and 2018YFA0404701)+1 种基金the National Natural Science Foundation of China(Grant Nos.11603081,11673073,U1831202,and 11873099)PICS projects between the CAS and the CNRS.
文摘We report on the investigation of optimal bias region of a wide-band superconducting hot electron bolometer(HEB)mixer in terms of noise temperature performance for multi-pixel heterodyne receiver application in the 5-meter Dome A Terahertz Explorer(DATE5)telescope.By evaluating the double sideband(DSB)receiver noise temperature(Trec)across a wide frequency range from 0.2 THz to 1.34 THz and with a large number of bias points,a broad optimal bias region has been observed,illustrating a good bias applicability for multipixel application since the performance of the HEB mixer is uniquely determined by each bias point.The noise temperature of the HEB mixer has been analyzed by calibrating the noise contribution of all RF components,whose transmissions have been measured by a time-domain spectroscopy.The corrected noise temperature distribution shows a frequency independence relation.The dependence of the optimal bias region on the bath temperature of the HEB mixer has also been investigated,the bath temperature has limited effect on the lowest receiver noise temperature until 7 K,however the optimal bias region deteriorates obviously with increasing bath temperature.
文摘超导HEB(Hot Electron Bolometer)热电子混频器是1THz以上灵敏度最高的相干探测器,为了进一步提高其灵敏度,有效减小射频信号在传输路径中的损耗,实现超导HEB混频器的超宽带混频功能,设计高耦合效率的射频匹配电路尤为重要。首先提出了混频器耦合电路的理论模型,然后采用三维电磁场仿真软件HFSS和类似于准光学天线的集总源法,设计了一种超宽带、低损耗的太赫兹信号耦合电路,对超导HEB混频器的嵌入阻抗在整个0.9～1.3THz的工作频带范围内进行了详细的分析。系统研究了低通滤波器中高低阻抗线结构,波导到微带转换中存在的高次模对射频信号传输的影响,并模拟仿真了实验中可能出现的磨片厚度误差对嵌入阻抗的影响。分析结果表明,该混频器的嵌入阻抗为35Ω-j10Ω左右,在整个工作频带内变化缓慢,能够实现超宽频带匹配,混频器的相对工作带宽可达到36%,仿真结果和理论模型计算结果完全一致。该研究结果对研制超宽带高灵敏度的超导HEB混频器具有很好的指导意义。
