Since the conception of radio astronomy [1], researchers have been striving to develop a "zero-noise" broadband receiver. Although this goal has remained elusive, the pursuit of it has led to numerous low-noise circuit innovations [2], [3]. Perhaps the most notable of these innovations are cryogenic low-noise amplifiers (cryo-LNAs) [3]-[6] as this technology has been able to achieve the lowest noise levels to date. While references to cryogenic amplifiers in the literature date back to the early 1950s [7], they are still a subject of much interest among researchers. Cryo-LNAs were initially conceived of to address challenges in the fields of space exploration [8], [9] and radio astronomy [10]. More recently, researchers in other fields have become interested in "zero-noise" receivers, making this a topic of widespread interest among RF and microwave engineers.

中文翻译：

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低温噪声参数测量：最新研究和全自动测量应用

自从射电天文学[1]的概念出现以来，研究人员一直在努力开发一种“零噪声”宽带接收器。虽然这个目标仍然难以实现，但对它的追求已经导致了许多低噪声电路的创新[2]、[3]。这些创新中最引人注目的可能是低温低噪声放大器 (cryo-LNA) [3]-[6]，因为该技术能够实现迄今为止的最低噪声水平。虽然文献中对低温放大器的引用可以追溯到 1950 年代初期 [7]，但它们仍然是研究人员非常感兴趣的主题。Cryo-LNA 最初的构想是为了应对空间探索 [8]、[9] 和射电天文学 [10] 领域的挑战。最近，其他领域的研究人员对“零噪声”接收器产生了兴趣，