【摘要】 设计了基于铌(Nb)超导隧道结低噪声220 GHz太赫兹混频器。通过锤型(hammer-head)射频截止滤波器的设计减小芯片尺寸，降低信号传输损耗，同时提供更宽的阻带，阻止射频和本振信号的泄露。为有效提高混频效率，建立隧道结模型优化混频电路，使信号平均传输到每个结上。结合软件仿真和数值模拟得到混频器在180-250 GHz的射频范围内具有正向的变频增益，中频输出带宽达到15 GHz,噪声温度小于20 K,介于两倍和三倍量子极限之间。结果表明该设计具有突出的射频、中频带宽和极高的灵敏度。更多还原

【Abstract】 A low-noise 220 GHz mixer at Terahertz band based on the Nb superconducting tunnel junctions was designed.Harmmer-head RF chock filter was managed to reduce the chip size and decrease the signal transmission loss, while a wider stop-band was provided to prevent the leakage of RF and LO signals. In order to improve mixing efficiency, a model of the tunnel junction was established for optimizing the mixing circuit so that the signal can be transmitted equally to each junction. Combining with software simulation and numerical simulation, conversion gain is proved to be positive in the RF range of 180-250 GHz, and the IF frequency output bandwidth reaches 15 GHz, while the noise temperature is less than 20 K that is between twice and triple the quantum limit.The simulation results show the prominent RF and IF bandwidth and high sensitivity can be achieved.更多还原