C-band superconductor/semiconductor hybrid field-effect transistor amplifier on a LaAlO3 substrate

A single-stage C-band superconductor/semiconductor hybrid field-effect transistor amplifier was designed, fabricated, and tested at 77 K. The large area (1 inch x 0.5 inches) high temperature superconducting Tl-Ba-Ca-Cu-O (TBCCO) thin film was rf magnetron sputtered onto a LaAlO3 substrate. The film had a transition temperature of about 92 K after it was patterned and etched. The amplifier showed a gain of 6 dB and a 3 dB bandwidth of 100 MHz centered at 7.9 GHz. An identical gold amplifier circuit was tested at 77 K, and these results are compared with those from the hybrid amplifier

Performance of a Y-Ba-Cu-O superconducting filter/GaAs low noise amplifier hybrid circuit

A superconducting 7.3 GHz two-pole microstrip bandpass filter and a GaAs low noise amplifier (LNA) were combined into an active circuit and characterized at liquid nitrogen temperatures. This superconducting/semiconducting circuit's performance was compared to a gold filter/GaAs LNA hybrid circuit. The superconducting filter/GaAs LNA hybrid circuit showed higher gain and lower noise figure than its gold counterpart

Method and Apparatus for Testing Microwave Devices and Circuits in a Controlled Environment

A test system is disclosed that enables the testing of microwave components in a controlled environment without disturbing that environment. The system includes a test fixture which holds the calibration standards and the component being tested, and environmental control chamber, and a microwave switching system. The system provides a coaxial connection to microwave testing equipment, such as an automatic network analyzer (ANA) and facilitates both calibration and testing while maintaining environmental integrity

A Single-Block TRL Test Fixture for the Cryogenic Characterization of Planar Microwave Components

The High-Temperature-Superconductivity (HTS) group of the RF Technology Branch, Space Electronics Division, is actively involved in the fabrication and cryogenic characterization of planar microwave components for space applications. This process requires fast, reliable, and accurate measurement techniques not readily available. A new calibration standard/test fixture that enhances the integrity and reliability of the component characterization process has been developed. The fixture consists of 50 omega thru, reflect, delay, and device under test gold lines etched onto a 254 microns (0.010 in) thick alumina substrate. The Thru-Reflect-Line (TRL) fixture was tested at room temperature using a 30 omega, 7.62 mm (300 mil) long, gold line as a known standard. Good agreement between the experimental data and the data modelled using Sonnet's em(C) software was obtained for both the return (S(sub 11)) and insertion (S( 21)) losses. A gold two-pole bandpass filter with a 7.3 GHz center frequency was used as our Device Under Test (DUT), and the results compared with those obtained using a Short-Open-Load-Thru (SOLT) calibration technique

Physical Properties and Thermal Stability of Zirconium Platinum Nitride Thin Films

Ternary transition metal nitrides (TMNs) promise to significantly expand the material design space by opening new functionality and enhancing existing properties. However, most systems have only been investigated computationally and limited understanding of their stabilizing mechanisms restricts translation to experimental synthesis. To better elucidate key factors in designing ternary TMNs, we experimentally fabricate and analyze the physical properties of the ternary Zr-Pt-N system. Structural analysis and DFT modeling demonstrate that Pt substitutes nitrogen on the non-metallic sublattice, which destabilizes the rock-salt structure and forms a complex cubic phase. We also show insolubility of Pt in the Zr-Pt-N at 45 at % with the formation of a secondary Pt-rich phase. The measured reduced plasma frequency, decrease in resistivity, and decrease in hardness reflect a dominance of metallic behavior in bonding. Contrary to previous computational predictions, Zr-Pt-N films are shown to be metastable systems where even low Pt concentrations (1%) facilitate a solid reaction with the Si-substrate, that is inaccessible in ZrN films.Comment: 6 pages, 3 figure

Die Entstehung und Verbreitung der italienischsprachigen antislawischen Propaganda in Triest

Die Entstehung einer italienischsprachigen antislawischen Propaganda in Triest war ein vielfältiger Prozess, der von verschiedenen inneren und äußeren Faktoren wirtschaftlicher, sozialer und politischer Art verursacht wurde. Der Antislawismus versammelte mehrere Richtungen der italienischsprachigen Mittelschicht und Intellektuellen um den nordöstlichen Adriaraum – Küstenland und Dalmatien. Die antislawische Propaganda gestaltete sich nur zum kleinen Teil als eine klare italienfreundliche-frühirredentistische Strömung, wie beispielsweise bei einigen radikalisierten Ideologen. Die Darstellung des Gesinnungswandels in Richtung Antislawismus einiger italienischsprachiger Intellektueller des Adriaraums vor und nach der Märzrevolution 1848 zeigte einerseits die Durchsetzung der neuen Bedingungen in den 1850er/60er Jahre. Anderseits ist in den Schriften dieser Autoren eine Art „roter Faden“ in Bezug auf die Betrachtungen über die Slawen erkennbar. Im Allgemeinen zeigte sich der Antislawismus als sozialer und politischer Identitätsfaktor und Bindekraft für die italienischsprachige Mittelschicht des Küstenlandes und Triests. Der Antislawismus war in Triest seit den 1860er Jahren mehr als eine politische und soziale konservative Reaktion der italienischsprachigen Mittelschicht, die in diesem Zeitraum im gesellschaftlichen und politischen Aufstieg der Adriastadt begriffen war. Die Krise des Freihafens Triests, die Internationalisierung des Handels und der politische Aufruhr mit dem Beginn der konstitutionellen Phase in der gesamten Monarchie boten dieser davon betroffenen Mittelschicht nun die Möglichkeit, persönlich ihre Interessen in der Öffentlichkeit zu vertreten, zu verteidigen und durchzusetzen. Die Vertretung der parallel dazu aufstrebenden slowenischsprachigen Mittelschicht wurde in diesen Jahren als eine konkurrenzfähige, politische und wirtschaftliche Alternative für die von beiden Seiten angestrebte hegemoniale Kontrolle der Knotenpunkte der Triestiner Gesellschaft wahrgenommen. In diesem komplexen Rahmen, neben dem Antislawismus, spielte die Wiederentdeckung des Autonomiemythos der Stadt Triest für die Identität der italienischsprachigen liberalnationalen Partei Triests eine zentrale Rolle. In diesem Sinn stellte sich die antislawische Propaganda in den 1860er Jahren in Triest nicht unbedingt als „italienisch“ dar, sondern eher als eine „triestinische“ protektionistische Reaktion des damaligen generellen Wandels. Um die vielfältige Entwicklung des Antislawismus im oberadriatischen Raum aus neueren Perspektiven zu betrachten, war es wichtig, die „Raumtheorien“ und die neue historische Analysemethode der mental maps anzuwenden.The development of Italian language anti-Slavic propaganda in Trieste was a multifaceted process, arising from a variety of economic, social and political factors – both internal and external. Anti-Slavism was the result of several tendencies of the Italian-speaking middle class and intellectuals in the north-eastern Adriatic area (Littoral and Dalmatia). Anti-Slavic propaganda represented only minimally a clear pro-Italian/pre-irredentist agenda, as it did with some nationalist ideologists. The change of opinion towards Anti-Slavism of some Italian-speaking intellectuals in the Adriatic area in the wake of the revolution of March 1848 revealed, on the one hand, the coming about of new general conditions in the 1850s/1860s; on the other hand, the works of these authors before and after the revolution contain a common thread concerning their opinions about the Slavic peoples. In general, Anti-Slavism constituted a factor of social and political identification and cohesion for the Italian-speaking middle class of the Littoral and of Trieste. From the 1860s Anti-Slavism in Trieste was largely a political and social conservative reaction of the Italian-speaking middle class, which in those years was establishing itself as the leading social and political force in the city. The crisis of the free port of Trieste, the internationalization of trade and the political unrest following the beginning of the constitutional period in the Habsburg Monarchy gave this middle class the opportunity to represent, protect and impose its own interests. The parallel rise of the Slovenian-speaking middle class was perceived as a dangerous political and economic alternative for the hegemonic control over key points in Triestine society. In such a complex situation, Anti-Slavism must be considered vis-à-vis the revival of the myth of Trieste's autonomy which was crucial for the identity of the local Italian-speaking Liberal-National Party. For this reason anti-Slavic propaganda took shape in Trieste during the 1860s not really as an Italian ideology, but rather as a Triestine protectionist reaction against the general transformations which were taking place at the time. In order to analyze the composite development of Anti-Slavism in the Northern Adriatic area from a new perspective, it was necessary to make use of the “special turn” theories and the new methodologies of analysis of “mental maps”