Plug & Test at System Level via Testable TLM Primitives

With the evolution of Electronic System Level (ESL) design methodologies, we are experiencing an extensive use of Transaction-Level Modeling (TLM). TLM is a high-level approach to modeling digital systems where details of the communication among modules are separated from the those of the implementation of functional units. This paper represents a first step toward the automatic insertion of testing capabilities at the transaction level by definition of testable TLM primitives. The use of testable TLM primitives should help designers to easily get testable transaction level descriptions implementing what we call a "Plug & Test" design methodology. The proposed approach is intended to work both with hardware and software implementations. In particular, in this paper we will focus on the design of a testable FIFO communication channel to show how designers are given the freedom of trading-off complexity, testability levels, and cos

Intertwined Rashba, Dirac and Weyl Fermions in Hexagonal Hyperferroelectrics

By means of density functional theory based calculations, we study the role of spin-orbit coupling in the new family of ABC hyperferroelectrics [Phys. Rev. Lett. 112, 127601 (2014)]. We unveil an extremely rich physics strongly linked to ferroelectric properties, ranging from the electric control of bulk Rashba effect to the existence of a three dimensional topological insulator phase, with concomitant topological surface states even in the ultrathin film limit. Moreover, we predict that the topological transition, as induced by alloying, is followed by a Weyl semi-metal phase of finite concentration extension, which is robust against disorder, putting forward hyperferroelectrics as promising candidates for spin-orbitronic applications.Comment: 5 pages, 3 figure

A true-time-delay networks design technique

This paper proposes a technique to design wide band switched-line (SL) true-time-delay (TTD) networks, commonly used for phased array antenna (PAA) applications. This study investigates the constant-delay behavior of switched-line phase shifters based on single-pole double-throw (SPDT) switches. Circuit sizing starts by considering the effective S-parameters of the switches, to use their non-idealities as an integral part of the phase shift linearly dependent to the frequency and by considering, from the beginning, the possible spatial positioning of elements that allows the circuit feasibility as a design target. The aim of this study is to provide a technique suitable for the design of well-matched TTD networks with a flat delay in wide bandwidth. In this paper, we propose new design formulas for which we show a single-frequency implementation. A computational strategy is used to obtain numerical solutions of the derived equations with this study. Finally, a monolithic X-band TTD circuit example is shown

An Innovative Lens Type FinLine to Microstrip Transition

Due to the disadvantages of vacuum tubes in terms of warm-up time, size, and highvoltage needs, solid-state power amplifiers (SSPAs) with gallium nitride (GaN) monolithic microwave integrated circuits (MMICs) are the key solution for power levels up to some kilowatts in continuous wave. An SSPA is the most convenient solution for these RF power levels due to its low weight, small size, negligible warm-up time, low-voltage operation, and high reliability. Spatial power amplifiers (SPAs) combining techniques are the best candidates for SSPAs due to the intrinsic low attenuation in dividing and combining functions. SPAs mainly use two types of probes: transverse and longitudinal, such as FinLines. This paper describes a broadband FinLine to microstrip (FLuS) transition based on dielectric lens theory. Comparative simulations with traditional FinLine transitions show a significant improvement in matching performances and a very significant increase in mechanical resistance of the transition. The proposed innovative FLuS uses a substrate shaping designed according to dielectric lens theory. Frequency simulations of a FLuS inside the WR22 waveguide are shown. These evidence the better performances of this transition than the classic FLuS transition using quarter-wave transformer (QWT) matching. A Q band spatial power combiner with dielectric lens FLuS was made and measured, showing the excellent performances of this innovative FLuS transition

"All on short" prosthetic-implant supported rehabilitations

Objectives. Short implants are increasing their popularity among clinicians who want to fulfill the constant demanding of fixed prosthetic solutions in edentulous jaws. The aim of this report was to propose a new possibility to project and realize an occlusal guided implant cross-arch prosthesis supported by ultra-short implants, describing it presented an edentulous mandible case report. Methods. A 61-year-old, Caucasian, female patient who attended the dental clinic of the University of L’Aquila presented with edentulous posterior inferior jaw and periodontitis and periimplantitis processes in the anterior mandible. The remaining tooth and the affected implant were removed. Six 4-mm-long implants were placed to support a cross-arch metal-resin prosthesis. Results. At 1-year follow-up clinical and radiological assessment showed a good osseointegration of the fixtures and the patient was satisfied with the prosthesis solution. Conclusion. The method, even if it requires further validation, seems to be a valid aid in solving lower edentulous clinical cases, and appears less complex and with more indications of other proposals presented in the current clinical literature. Our case report differs from the current technique All-on-Four, which uses four implants in the mandible to support overdenture prosthesis, assuring a very promising clinical resul

Innovative Mode Enhancement for High Power Coaxial Vircators

The size and weight of a high power microwave (HPM) source can make a difference in strategic use. The compactness of the virtual cathode oscillator (vircator) is undoubtedly the most significant advantage of this device. Civil industry and agriculture can use it to treat objects, food, and soils for disinfestation and disinfection. Vircators could also generate electromagnetic pulses (EMPs) to force the arrest of vehicles and drones; EMPs could inhibit or activate improvised explosive devices (IEDs). The coaxial type vircator is a highly compact device. Due to its symmetric geometry, coaxial vircator is typically designed to work with a TM01 mode. Still, when radiated into space, this mode gives maximum RF energy away from the antenna axis, a situation not desired. Instead, the TE11 is convenient in applications involving precise antenna pointing since this mode gives a maximum RF energy precisely aligned to the antenna axis. By studying Mathieu functions applied to elliptical waveguides, we improve the performances of a TE11 mode coaxial vircator using an elliptic drift tube (EDT). This is a completely innovative solution to reduce the mode competition inside the coaxial vircator. The rms and peak output power efficiency of the EDT coaxial vircator were measured on the TE11 mode, obtaining the values of 6.1% and 10%, respectively, with a peak power of 450 MW in a highly compact device

Virtual prototype of innovative ka-band power amplifier based on waveguide polarizer

This paper outlines an innovative approach to design a spatial power-combining structure based on waveguide polarizers. It presents the 3D CAD model of the new structure with the transversal probes and considerations in positioning and optimization of them. Exploiting the transformation of the dominant input mode TE10 into an elliptically polarized wave, provided by the polarizer, it has been possible to achieve a division of power by eight, completely carried out in space. With the insertion of the transversal probes made by microstrips, the RF signal can be sent to the MMIC solid state power amplifiers, and then recombined in the output section. Thanks to the large number of power divisions made in the waveguide section, the insertion loss of the power divider/combiner is less than 0.5 dB across the 32-34 GHz band, achieving a great power density as well. At the authors’ best knowledge, this is the first work where a waveguide polarizer is used in Spatial Power Combining technology

Progress in THz Rectifier Technology: Research and Perspectives

Schottky diode (SD) has seen great improvements in the past few decades and, for many THz applications, it is the most useful device. However, the use and recycling of forms of energy such as solar energy and the infrared thermal radiation that the Earth continuously emits represent one of the most relevant and critical issues for this diode, which is unable to rectify signals above 5 THz. The goal is to develop highly efficient diodes capable of converting radiation from IR spectra to visible ones in direct current (DC). A set of performance criteria is investigated to select some of the most prominent materials required for developing innovative types of electrodes, but also a wide variety of insulator layers is required for the rectification process, which can affect the performance of the device. The current rectifying devices are here reviewed according to the defined performance criteria. The main aim of this review is to provide a wide overview of recent research progress, specific issues, performance, and future directions in THz rectifier technology based on quantum mechanical tunneling and asymmetric structure

First report of caprine abortions due to Chlamydia abortus in Argentina.

Infectious abortions of goats in Argentina are mainly associated with brucellosis and toxoplasmosis. In this paper, we describe an abortion outbreak in goats caused by Chlamydia abortus. Seventy out of 400 goats aborted. Placental smears stained with modified Ziehl-Neelsen stain showed many chlamydia-like bodies within trophoblasts. One stillborn fetus was necropsied and the placenta was examined. No gross lesions were seen in the fetus, but the inter-cotyledonary areas of the placenta were thickened and covered by fibrino-suppurative exudate. The most consistent microscopic finding was found in the placenta and consisted of fibrinoid necrotic vasculitis, with mixed inflammatory infiltration in the tunica media. Immunohistochemistry of the placenta was positive for Chlamydia spp. The results of polymerase chain reaction targeting 23S rRNA gene performed on placenta were positive for Chlamydia spp. An analysis of 417 amplified nucleotide sequences revealed 99% identity to those of C. abortus pm225 (GenBank AJ005617) and pm112 (GenBank AJ005613) isolates. To the best of our knowledge, this is the first report of abortion associated with C. abortus in Argentina

On integrating a proprietary and a commercial architecture for optimal BIST performances in SoCs

This paper presents the integration of a proprietary hierarchical and distributed test access mechanism called HD2BIST and a BIST insertion commercial tool. The paper briefly describes the architecture and the features of both the environments and it presents some experimental results obtained on an industrial So