MIDAS: Automated Approach to Design Microwave Integrated Inductors and Transformers on Silicon

The design of modern radiofrequency integrated circuits on silicon operating at microwave and millimeter-waves requires the integration of several spiral inductors and transformers that are not commonly available in the process design-kits of the technologies. In this work we present an auxiliary CAD tool for Microwave Inductor (and transformer) Design Automation on Silicon (MIDAS) that exploits commercial simulators and allows the implementation of an automatic design flow, including three-dimensional layout editing and electromagnetic simulations. In detail, MIDAS allows the designer to derive a preliminary sizing of the inductor (transformer) on the bases of the design entries (specifications). It draws the inductor (transformer) layers for the specific process design kit, including vias and underpasses, with or without patterned ground shield, and launches the electromagnetic simulations, achieving effective design automation with respect to the traditional design flow for RFICs. With the present software suite the complete design time is reduced significantly (typically 1 hour on a PC based on Intel® Pentium® Dual 1.80GHz CPU with 2-GB RAM). Afterwards both the device equivalent circuit and the layout are ready to be imported in the Cadence environment

Surface impedance measurements on Nb3_{3}Sn at high magnetic fields

Nb$_{3}$Sn is a superconductor of great relevance for perspective RF applications. We present for the first time surface impedance $Z_s$ measurements at 15 GHz and low RF field amplitude on Nb$_{3}$Sn in high magnetic fields up to 12 T, with the aim of increasing the knowledge of Nb$_{3}$Sn behavior in such conditions. $Z_s$ is a fundamental material parameter that directly gives useful information about the dissipative and reactive phenomena when the superconductor is subjected to high-frequency excitations. Therefore, we present an analysis of the measured $Z_s$ with the aim of extracting interesting data about pinning in Nb$_{3}$Sn at high frequencies. From $Z_s$ we extract the vortex motion complex resistivity to obtain the $r$-parameter and the depinning frequency $\nu_p$ in high magnetic fields. The comparison of the results with the literature shows that the measured $\nu_p$ on bulk Nb$_{3}$Sn is several times greater than that of pure Nb. This demonstrates how Nb$_{3}$Sn can be a good candidate for RF technological applications, also in high magnetic fields.Comment: ASC 2018 conference, accepted in IEEE Trans Appl Supercon

uRT51: An Embedded Real-Time processor implemented on FPGA devices

In this paper we describe and evaluate the main features of the uRT51 processor. The uRT51 processor was designed for embedded realtime control applications. It is a processor architecture that incorporates the specific functions of a real-time system in hardware. It was described using synthesizable VHDL and it was implemented on FPGA devices. We describe how the uRT51 processor supports time, events, task and priorities. The performance of the uRT51 processor is evaluated using a control application as a case study. The experiments show that the uRT51 processor scheduling features outperform the ones obtained using a traditional RTOS-based real-time system.Fil: Cayssials, Ricardo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; ArgentinaFil: Duval, M,. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; ArgentinaFil: Ferro, Edgardo Carlos. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; ArgentinaFil: Alimenti, O.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; Argentin

Tocar el tango hoy: estilo compositivo y estilo de ejecución

El estilo del tango se ha desarrollado al calor de sus prácticas de ejecución. Para investigarlo se necesita incorporar al análisis de la composición escrita, el estudio de sus rasgos performativos, postulando una interdependencia entre estilo compositivo y estilo de ejecución. Así, movimiento, sonido, texto musical y práctica en contexto forman el corpus del presente trabajo.Área: Ciencias Sociales y Humana

Tocar el tango en estilo

El tango es un género sonoro-gestual complejo en el que la danza, la canción y la música instrumental se fueron combinando a través del tiempo. Por esta razón la gestualidad emergente de su práctica puede ser abordada a través del análisis del sonido y el movimiento de los instrumentistas. En el presente trabajo nos proponemos indagar acerca del complejo sonoro-kinético del tango en vinculación con el análisis gramatical del texto musical, entendido como guión de la performance (Cook, 2003) y con la pretensión de aportar explicaciones para comprender la experiencia musical del ejecutante de tango. Se describe el tratamiento a nivel local (dimensión compositiva) en Aníbal Troilo en combinación con el movimiento de los músicos cuando ejecutan las acentuaciones de los esquemas métricos (dimensión performativa), y el tratamiento a nivel global (dimensión compositiva) en Osvaldo Pugliese en vinculación con los acentos expresivos en el desarrollo del ritmo tonal y duracional (dimensión performativa). Se concluye que el análisis de los niveles métricos y la descripción de ciertos gestos sonoro-kinéticos de los ejecutantes dejan al descubierto una diferencia en la organización de la jerarquía métrica puesta en acción durante la performance, la cual contribuye a la identidad estilística-musical de cada autor

Vortex pinning and flux flow microwave studies of coated conductors

Demanding microwave applications in a magnetic field require the material optimization not only in zero-field but, more important, in the in-field flux motion dominated regime. However, the effect of artificial pinning centers (APC) remains unclear at high frequency. Moreover, in coated conductors the evaluation of the high frequency material properties is difficult due to the complicated electromagnetic problem of a thin superconducting film on a buffered metal substrate. In this paper we present an experimental study at 48 GHz of 150-200 nm YBa$_2$Cu$_3$O$_{7-x}$ coated conductors, with and without APCs, on buffered Ni-5at%W tapes. By properly addressing the electromagnetic problem of the extraction of the superconductor parameters from the measured overall surface impedance $Z$, we are able to extract and to comment on the London penetration depth, the flux flow resistivity and the pinning constant, highlighting the effect of artificial pinning centers in these samples.Comment: 5 pages, IEEE Trans. Appl. Supercond., accepted for publication (2019

Superconductor Microwave Kinetic Inductance Detectors: System Model of the Readout Electronics

This paper deals with the readout electronics needed by superconductor Microwave Kinetic Inductance Detectors (MKIDs). MKIDs are typically implemented in the form of cryogenic-cooled high quality factor microwave resonator. The natural frequency of these resonators changes as a millimeter or sub-millimeter wave radiation impinges on the resonator itself. A quantitative system model of the readout electronics (very similar to that of a vector network analyzer) has been implemented under ADS environment and tested by several simulation experiments. The developed model is a tool to further optimize the readout electronic and to design the frequency allocation of parallel-connected MKIDs resonators. The applications of MKIDs will be in microwave and millimeter-wave radiometric imaging as well as in radio-astronomy focal plane arrays

THE PROTEIN PHEROMONE FAMILY OF E. PETZI, A PSYCHROPHILIC AND EARLY BRANCHING EUPLOTES SPECIES

Euplotes species are valuable for the study of the structural and functional biology of water-borne protein pheromones that cells constitutively synthesize and use in intra-specific chemical communication. We have recently devoted particular attention to the pheromone family of the “cold loving” (psychrophilic) species E. petzi which dwells in the freezing Antarctic and Arctic coastal sea waters, and forms, together with E. sinicus, the earliest branch of the Euplotes phylogenetic tree. From cultures of genetically distinct strains, we have isolated and sequenced four E. petzi pheromones. With respect to the known pheromones from E. raikovi, E. octocarinatus, E. nobilii and E. crassus, the E. petzi pheromones are smaller (32 amino acids) and richer in Cys residues (eight) located in strictly conserved positions. These residues are predicted to form four intra-chain disulfide bridges, which suggests a compact globular fold of the molecules. However, the NMR solution structure determined for one of the E. petzi pheromones challenges this hypothesis. The structure consists of one more extended eight-residue alpha-helix and one smaller four-residue helix, and shows large polypeptide segments devoid of regular secondary structures. Pheromones from other Euplotes species which live in temperate waters and branch later than E. petzi in the Euplotes phylogenetic tree are known to be characterized by a three-helix fold and unstructured regions of comparatively limited dimensions. In the light of this knowledge, we can thus draw two distinct conclusions from our findings. The first, of phylogenetic nature, is that the structural evolution of the Euplotes pheromones involves an increase in size and complexity. This is in line with the smaller and simpler organization that also the macronuclear E. petzi pheromone genes show with respect to their homologues in other Euplotes species. The second conclusion is that the extended unstructured regions of E. petzi pheromones are likely correlated with an increased flexibility of the molecular backbone and, hence, reflect a common feature of protein cold-adaptation. In this regard, further insights will be obtained by ongoing experiments which aim to assess the unfolding and refolding properties of E. petzi pheromones when exposed to increased temperatures and variations of other environmental parameters