Contactless non-leaking waveguide flange realized by bed of nails for millimeter wave applications

Waveguide flanges are typically used to connect and measure high frequency circuits. When good conductive contact is not provided between the joining flange surfaces, currents will flow between them, and thereby causing leakage and losses affecting the circuit performance. This work presents a non-leaking contactless waveguide flange made with bed of nails. The flange does not need any contact when connected to another smooth flange, since the pins surface and the smooth surface together form a stopband suppressing any current and wave propagation between the two joining surfaces of the flanges

La Convergenza tecnologica: aspetti tecnici, mercati interessati e tentativi di regolazione

L’elaborato analizza, sotto vari aspetti, il fenomeno della convergenza tecnologica, il quale, per mezzo della digitalizzazione e dello sviluppo innovativo, ha subito nel corso degli ultimi anni un’evoluzione senza precedenti. Nel primo capitolo è stato inizialmente fatto accenno alla Rivoluzione digitale e all’invenzione del linguaggio binario, divenuto linguaggio comune a più mezzi tecnologici. A seguito di una breve riflessione sulle conseguenze socio-culturali del fenomeno della convergenza, sono stati descritti i principali aspetti tecnici dei mezzi protagonisti della convergenza multimediale; in particolare è stato analizzato da vicino la struttura del personal computer, fulcro della tecnologia multimediale, per poi passare alla descrizione dell’apparecchio audiovisivo e della sua evoluzione dall’analogico al digitale, evoluzione che ha caratterizzato anche la telecomunicazione, ambito a dir poco rivoluzionato dall’integrazione con Internet e ultimamente approdato a device ultra-tecnologici come gli smartphone. Nel secondo capitolo, l’attenzione è stata in un primo momento concentrata sulla possibilità della presenza di monopoli e dello stato di concorrenza della TV in chiaro, per poi passare a descrivere l’evoluzione della TV a pagamento e l’introduzione dei nuovi protagonisti – attori e aggregatori - dell’audiovisivo, con i relativi modelli di business; allo stesso modo, si è parlato di come la convergenza abbia influito sul mercato delle telecomunicazioni, con offerte di tipo fisso-mobile e facendo riferimento, anche in questo caso a nuove figure del settore, come gli operatori “virtuali”; si è quindi fatto accenno ai recenti dati AGCOM e Istat, e quindi alle ultime tendenze registrate nei mercati della rete fissa e di quella mobile, con particolare riferimento allo sviluppo dell’offerta riferita ai servizi Web e alla diffusione di dispositivi abilitati in grado di connettersi in mobilità. Infine, nella terza e ultima parte è stato fatto accenno ad alcune direttive comunitarie e le conseguenti norme nazionali che, in maniera marginale o più diretta hanno tentato di disciplinare lo sviluppo della convergenza, regolando i settori interessati dal fenomeno. Una prima serie di direttive del 2002, successivamente modificate, ha inquadrato l’ormai ampio ambito delle comunicazioni elettroniche, recepite sul nostro territorio con l’omonimo codice. Le altre direttive trattate si sono invece preoccupate di regolamentare il settore dell’audiovisivo, nel 2007 e nel 2010, e anche in questo caso è stata descritta la relativa legge e i regolamenti con cui la direttiva comunitaria è stata recepita. Infine, si è parlato della neutralità tecnologica, la cui osservanza, in un futuro sempre più convergente, risulta essere fondamentale per il benessere dei consumatori, e dei valori che devono in ogni caso essere considerati nelle future legislazioni in materia

Compact loaded PIFA for multifrequency applications

A new multifrequency microstrip patch antenna is presented. The antenna can be considered a PIFA since it has a metallic wall on one of its sides. The different bands of operation are independent of each other, and different radiation patterns for each band can be achieved if desired. In addition, a circuital model is introduced to explain the operation of the antenna. This model presents some similarities with composite right left handed models presented in the literature. Some prototypes have been manufactured and measurements of return losses, efficiencies and radiation patterns, have been performed for a thorough characterization of the antenna as well as to validate the simulation results

New Microstrip Gap Waveguide on Mushroom-Type EBG for Packaging of Microwave Components

The gap waveguide has been recently presented as a new transmission line technology using artificial magnetic conductors (AMCs) to allow the wave propagation only along a desired path. The first validation has been provided using a lid of metal pins as AMC for high frequency applications. In this letter, simulations and measurement results are presented for another version called microstrip gap waveguide, working as inverted microstrip line and realized using a mushroom-type EBG surface. The transmission line is surrounded by mushrooms which create a parallel plate stop band, suppressing cavity modes and unwanted radiations compared to standard packaged microstrip transmission lines. The field propagates in the air gap between the upper lid and the mushrooms layer, providing a low loss compact circuit made in printed technology

Evaluation of losses in microstrip gap waveguide for slot antennas applications

The new microstrip gap waveguide supports a quasi-TEM mode in the air by the use of artificial magnetic conductors which force the field to travel in the air rather than in the substrate. This paper presents an evaluation of losses by measuring the Q-factor of a resonator made in this technology, made using a mushroom-type EBG surface. Losses are crucial when using printed circuits to feed slot antennas, thereby motivating this work. Comparisons with standard microstrip lines will be provided, showing promising results

Gender differences and tech-based entrepreneurship: a literature review and research agenda

Despite the widespread recognition of the growing, positive contribution of female entrepreneurship in economic and social development processes, women are still less involved in high-growth entrepreneurship, especially in Europe, where their participation is lower than in most part of the world, and where they show some of the lowest rates of entrepreneurial perceptions (seeing new business opportunities, having the skills to start a new business, being undeterred by fear of failure), according to Women's Entrepreneurship GEM Report (2021). Gender gap in entrepreneurship and management is confirmed by the European Institute for Gender Equality, whose statistics show that across the EU, women business owners make up only 33.2% of self-employed people, and management boards are dominated by men (EIGE Report, 2021). This gap is somewhat larger in tech-based industries, where founding and managing a technology-based firm has been commonly considered to be a male affair (Green et al., 2003; Nelson and Levesque, 2007) and prominently within STEM fields (Poggesi et al., 2020), where women entrepreneurs are still strongly underrepresented (Dautzenberg, 2012; Tonoyan and Strohmeyer, 2021). Since the seminal contribution of Schwartz (1976), the debate surrounding women and entrepreneurship has grown up, focusing on their underrepresentation and their “marginalization” into sectors with low growth perspectives (Carter et al., 2000). There has been, among scholars as well as policymakers, a tendency to interpret this evidence as the expression of female structural weaknesses, to be fixed through specific programs aimed at training women to adopt prototypical entrepreneurial attitudes (Marlow, 2019). Despite this generalized view, a different perspective emerged in the same years, suggesting that female entrepreneurship specificities had to be considered as the result of a generalized gendered subordination (Fischer, 1993; Jennings and Brush, 2013). Even though this topic has given rise to a substantial body of literature, there are relatively few studies dedicated to investigating the presence of women entrepreneurs in technology-based sectors. Except for a few recent works (Wheadon and Duval-Couetil, 2019; Poggesi et al., 2020) that propose a literature review on the topic of gender and technology entrepreneurship, there is currently no dedicated strand of research that, in the field of management, identifies the issue of gender differences with reference to high-tech entrepreneurship. This is even more surprising, when considering that today technology plays a pervasive role and that even mature industries are undergoing strong changes precisely because of the spread of new technologies related to STEM fields. This opens great opportunities from which, once again, women risk being excluded or marginalized. It is therefore important, in our opinion, to examine this issue in depth and take stock of the results of the research conducted so far. Given the above, our study has two overarching objectives. The first is to document the development of the body of work related to gender differences and high-tech entrepreneurship. The second is to assess its contributions vis-a-vis the broader corpus of literature on female entrepreneurship

Blending “hard” and “soft” TQM for academic excellence: the University of Siena experience in the field of Life Sciences

Purpose – Focusing on the adoption of Total Quality Management (TQM) principles in universities, this research paper explores how the “soft” dimensions of TQM trigger its “hard” dimensions considering them at the individual (micro-) and the university (meso-), and eventually at cluster (system-), levels. Design/methodology/approach – Adopting a qualitative approach, this study presents an in-depth, longitudinal case study of University of Siena, one of the oldest Italian universities, that has been at the core of the research-based cluster on vaccines, today converged in the Tuscan Life Science Cluster. In particular, data were collected between 2018 and February 2022 and consists of archival data (press articles, websites, books), nine interviews to key informants, multiyear experience of the Life Sciences sector by two of the authors and other material put at disposal by university offices, and emails. Data analysis relied on a timeline, a coding procedure that considered three levels of analysis (individual, organization and cluster). Finally, the authors looked at the “how” and “why” the emerged themes have contributed to academic excellence. Findings – This paper unveils how “soft” and “hard” sides of TQM are blended across multiple levels for reaching academic excellence. The grounded model emerged enlightens the importance of an individual “soft” dimension, academic passion (composed by its three subdimensions of individual research, teaching and entrepreneurial passion) and also sheds light on the organizational “soft” and “hard” sides that the university has been able to design for encouraging research, teaching and third mission quality. Academic excellence has been possible thanks to the capitalization of the individual and organizational“soft” sides into real outcomes as represented by the organizational and individual “hard” sides. Practical implications – The paper suggests the importance of TQM principles applied at universities’ level, providing an in-depth description of “soft” and “hard” sides dimensions of TQM and their impact on all the three pillars of academic excellence. The study findings suggest implications for managers and professionals in the higher education domain as well as for policymakers emphasizing the importance of supporting the individual and organizational soft sides of TQM. The authors provide practical implications recommending universities to consider not only the organizational dimensions but also individual ones when pursuing higher education excellence. In particular, individual passion plays a crucial role and universities need to identify ways of nurturing it. The authors also recommend policymakers to think about new ways to sustain universities as crucial actors in boosting a cluster development, as well as to consider higher education institutions, especially in more rural areas, as a privileged player not only capable of nurturing academic excellence but also able of creating an internationally renowned cluster. Originality/value – TQM principles have been intensively analysed from an industrial perspective focusing on manufacturing and services, while this paper focuses on TQM in universities, presenting a grounded model that blends the individual and organizational “soft” and “hard” sides

Gap waveguide components for millimeter-wave systems. Couplers, filters, antennas, MMIC packaging

Design of passive components (couplers, filters and antennas) and MMIC packaging validation intended for RF front ends for microwave links at 38 GHz using gap waveguide technology have been shown. The use of this technology allows all-in-one integration of receiver, transmitter, and diplexer including the antenna into one mechanical unit. These initial designs and studies have been made at the microwave band for validation and measurement purposes, and for comparison with existing technology. They represent the first step towards the application of gap waveguides to millimeter-wave systems, where gap waveguides could have a large potential

Suppression of Parallel Plate Modes in Low Frequency Microstrip Circuit Packages Using Lid of Printed Zigzag Wires

This work deals with the suppression of parallel plate and cavity modes in shielded microstrip circuits operating at the lower microwave frequency range. The suppression is achieved by using a lid made of zigzag wires printed periodically on narrow slices of ungrounded circuit boards, located vertically side by side. This structure is very compact both in periodicity and height, it suppresses cavity modes over about an octave 2: 1 bandwidth, and it does not interfere with the packaged microstrip circuit