Investigation of Superconducting Quasiparticle Mixers for Astronomical Receivers

基于超导体-绝缘体-超导体的接收器 (SIS)准粒子隧道结混频器现在已经超过了 传统的肖特基二极管接收器的灵敏度，并 对毫米波天文学产生了直接的影响。 即便如此，在这项技术能够 充分发挥其潜力。 因此，广泛的实验 毫米波和亚毫米波SIS结研究 探测器将进行更好的分析和直观 了解SIS混合器和相关现象，依靠 混合的量子理论，特别注意噪声 现象，最佳混频器设计参数，调谐结构，将 是排序，因为将适当的电容SIS结。 调查不太被广泛接受的检测方案，例如 SIN混频器、次谐波泵浦和SIS直接检测将 实验研究。 实验室制备的Nb/AlO/Nb结， 其具有非常低的泄漏电流， 在这项工作中。 这些路口将提供给无线电 天文学界对SIS接收机的发展。 这 调查应大大有助于设计和最终 实际SIS接收器的灵敏度;并可能导致 其它毫米波和亚毫米波探测器的研制 波长天文学

Receivers based upon the superconductor-insulator-superconductor (SIS) quasiparticle tunnel junction mixer have now surpassed conventional Schottky-diode receivers in sensitivity, and are having an immediate impact on millimeter-wavelength astronomy. Even so, much further research is needed before this technology can reach its full potential. Therefore, an extensive experimental study of SIS junctions as millimeter-and submillimeter-wave detectors will be undertaken better analytical and intuitive understanding of SIS mixers and related phenomena, relying on the quantum theory of mixing, with special attention to noise phenomena, optimum mixer design parameters, tuning structures, will be sort, as will the appropriate capacitance for SIS junctions. Investigation of less widely accepted detection schemes, such as SIN mixers, subharmonic pumping, and SIS direct detection will be Experimentally studied. The Nb/AlO/Nb juctions made in laboratory, which have extraordinarily low leakage currents, will be utilized in this work. These junctions will be made available to the radio astronomy community for SIS receiver devleopment. This investigation should greatly contribute to the design and ultimate sensitivity of practical SIS receivers; and may lead to the development of other detectors for millimeter and submillimeter wavelength astronomy.