{"title":"Josephson array oscillator with microstrip resonators for submillimeter wave region","authors":"Akira Kawakami, Yoshinori Uzawa, Zhen Wang","doi":"10.1016/S0964-1807(99)00045-9","DOIUrl":null,"url":null,"abstract":"<div><p>Shunted tunnel junctions with a small parasitic inductance have been developed for improving the operating frequency of Josephson array oscillators. The inductance was minimized by reducing the inductive length to 1<!--> <em>μ</em>m and was estimated to be about 40<!--> <!-->fH. The analysis of resonant properties for the shunted junctions gave a high resonant frequency up to 1.4<!--> <!-->THz. Josephson array oscillators were designed and fabricated to operate at near Nb gap frequency (700<!--> <!-->GHz) using 11 shunted Nb/AlO<em>x</em>/Nb tunnel junctions with Nb microstrip resonators. Shapiro steps induced by Josephson oscillation were clearly observed above the Nb gap frequency (up to 830<!--> <span>GHz). By fitting the step height to the simulation result using the RLCSJ model, the output power of the Josephson oscillator to the load resistor was estimated to be about 0.1</span> <em>μ</em>W at 680<!--> <!-->GHz.</p></div>","PeriodicalId":100110,"journal":{"name":"Applied Superconductivity","volume":"6 10","pages":"Pages 799-803"},"PeriodicalIF":0.0000,"publicationDate":"1999-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0964-1807(99)00045-9","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Superconductivity","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0964180799000459","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Shunted tunnel junctions with a small parasitic inductance have been developed for improving the operating frequency of Josephson array oscillators. The inductance was minimized by reducing the inductive length to 1 μm and was estimated to be about 40 fH. The analysis of resonant properties for the shunted junctions gave a high resonant frequency up to 1.4 THz. Josephson array oscillators were designed and fabricated to operate at near Nb gap frequency (700 GHz) using 11 shunted Nb/AlOx/Nb tunnel junctions with Nb microstrip resonators. Shapiro steps induced by Josephson oscillation were clearly observed above the Nb gap frequency (up to 830 GHz). By fitting the step height to the simulation result using the RLCSJ model, the output power of the Josephson oscillator to the load resistor was estimated to be about 0.1μW at 680 GHz.