Krasnov Vladimir M
Department of Physics, Stockholm University, AlbaNova University Center, SE-10691 Stockholm, Sweden.
Beilstein J Nanotechnol. 2023 Jan 26;14:151-164. doi: 10.3762/bjnano.14.16. eCollection 2023.
Optimization of Josephson oscillators requires a quantitative understanding of their microwave properties. A Josephson junction has a geometry similar to a microstrip patch antenna. However, it is biased by a dc current distributed over the whole area of the junction. The oscillating electric field is generated internally via the ac-Josephson effect. In this work, I present a distributed, active patch antenna model of a Josephson oscillator. It takes into account the internal Josephson electrodynamics and allows for the determination of the effective input resistance, which couples the Josephson current to cavity modes in the transmission line formed by the junction. The model provides full characterization of Josephson oscillators and explains the origin of the low radiative power efficiency. Finally, I discuss the design of an optimized Josephson patch oscillator capable of reaching high efficiency and radiation power for emission into free space.
约瑟夫森振荡器的优化需要对其微波特性有定量的理解。约瑟夫森结的几何形状类似于微带贴片天线。然而，它由分布在结的整个区域上的直流电流偏置。振荡电场通过交流约瑟夫森效应在内部产生。在这项工作中，我提出了一种约瑟夫森振荡器的分布式有源贴片天线模型。它考虑了内部约瑟夫森电动力学，并允许确定有效输入电阻，该电阻将约瑟夫森电流耦合到由结形成的传输线中的腔模。该模型提供了约瑟夫森振荡器的完整特性，并解释了低辐射功率效率的起源。最后，我讨论了一种优化的约瑟夫森贴片振荡器的设计，该振荡器能够实现高效率和辐射功率以发射到自由空间。
