This thesis discusses commensality as a significant social activity, that helps to maintain and strengthen social bonds. It also examines the sense of touch as a communication channel, and provides an insight to how it can be used to communicate affect. Touch as contextualized medium and its relevance to interaction design is investigated. Based on studies made in psychology, physiology, sociology and communication it aims to find an answer to the question: ”How may we create togetherness -with the help of an interactive device- between loved ones separated by distance during dining, through remote communication?” In order to meet the objectives of the above question this research followed the Research Through Design methodology, with series of workshops and prototyping sessions.

Black Lives Matter protests and rallies erupted in the summer of 2020 following several cases of police brutality in the US, including the death of George Floyd after video of him being killed by a police officer were shared in the media. These protests quickly spread internationally and pushed countries to face their own histories and structurally embedded racism, including Sweden. The aim of this thesis was to examine how the global spread of #BlackLivesMatter in 2020 helped mobilize a nationally relevant movement in Sweden via Facebook, despite its cultural history of disregarding the concept of race and the implications that has had on today. This is achieved through the exploration of interpreting information on social media and the construction of reality in media spheres, with the help of digitally networked action and transnationalism. This framework is accompanied by an inductive thematic analysis of the Black Lives Matter Facebook page in their first 30 days on the platform (June 3-July 3), which is where the organization based itself upon creation, ultimately leading to a sample of 52 posts. The main results of the study yielded three themes: US References, Nationally Relevant Issues (which produced three subthemes), and Action & Organizing. In conclusion, with regard to the research focus, the thesis reveals that this is achieved by a few choices. The organization's ability to use elements that greatly influence the US movement is balanced with factors that are more culturally specific to Sweden and the Black and brown communities here using a connective action frame in which users were able to seamlessly support and participate online and spread the message further. The conclusions implicate that the avoidance of discussing race/racism in Sweden clearly hasn’t helped or prevented Black and brown communities from being negatively impacted and that further research could potentially help guide future policies to solidify Sweden’s image of inclusion and equality.

The high demands on data processing and bandwidth in wireless/wireline communication and aerospace systems have been pushing forward circuit design techniques to their limitations to obtain maximum performances with respect to high operating frequency, low noise, small area, and low power consumption. Clock generators are essential components in numerous circuits, for instance, frequency synthesizers for high speed transceivers, clock sources for microprocessors, noise suppressed zero-delay buffers in system-on-chips (SOCs), and clock and data recovery (CDR) systems. Furthermore, clock generators are required to provide low jitter and high precision clocks in fully integrated image reject receivers and an ultra-wide tunability in time-interleaved applications. We explore several circuit design techniques and implementations of low jitter clock generator in this thesis. Firstly, a low jitter and wide range digital phase-locked loop (DPLL) operating 8 ~ 16 GHz is illustrated using a dual path digital loop filter (DLF). In order to mitigate the phase jitter in the phase detector (PD), we implement the separate loop filter and the output is not affected by the proportional path. For the stable operation, a 4 ~ 8 GHz linear phase interpolator (PI) is implemented in the proportional path. In addition, we design a low phase noise digitally controlled oscillator (DCO) using inductive tuning technique based on switched mutual coupling for wide operating range. The proposed DPLL implemented in 65 nm CMOS technology shows an outstanding figure-of-merit (FOM) over other state-of-art DPLLs in term of root mean square (RMS) and deterministic jitter (DJ). Secondly, we discuss a radiation-hardened-by-design (RHBD) PLL using a feedback voltage-controlled oscillator (FBVCO) in order to reduce DJ due to the radiation attack on the control voltage. Different from a conventional open loop VCO, the proposed FBVCO has a negative control loop and is composed of an open loop VCO, an integrator and a switched-capacitor resistor. Since the input to output of the FBVCO has a low-pass characteristic, any disturbance on the control voltage should be filtered and cannot affect the output phase. We are able to reduce the output frequency variation approximately 75% compared to the conventional PLL when the radiation pulse strikes on the control voltage. The proposed RHBD PLL is implemented in 130 nm and consumes 6.2 mW at 400 MHz operating frequency. Thirdly, a novel adaptive-bandwidth PLL is illustrated to optimize the jitter performance in a wide operating frequency range. We achieve a constant ratio of bandwidth and reference frequency with a closed loop VCO and an overdamping system with a charge pump (CP) current proportional to the VCO frequency for the adaptive-bandwidth technique. The proposed adaptive-bandwidth PLL presents 0.6% RMS jitter over the entire frequency range from 320 MHz to 2.56 GHz, which is 70% smaller than the conventional fixed-bandwidth PLL. Finally, we have developed a new feedback DCO to achieve a linear gain of DCO so that the DPLL can provide stability and a wide operating range in different process variations. Due to the negative feedback loop of the proposed DCO, the feedback DCO presents a linear gain from an input digital word to an output frequency. Moreover, we can control the bandwidth of the feedback DCO to optimize the total output phase noise in DPLL. In simulation, we can obtain 17 MHz/LSB of the peak-to-peak gain of the feedback DCO, which is reduced 96% over the conventional DCO.

While IS research into on-line Inter-Personal (IP) Social Networks (SN) is highly visible, there has been surprisingly little focus on the use of on-line social networks for Inter-Organizational (IO) communications, interactions, and goal achievement. We explore the issues and challenges facing organizations in their design and use of inter-organizational social network information systems (IO SNIS). Artifact design principles are drawn from a new and insightful model that contrasts the advantages of existing innovative inter-personal (IP) SNIS artifacts with Social Network Theory on differences between IP and IO Social Networks. This research extends the existing streams of IS social networking research into the inter-organizational domain and encourages additional IS research into the analysis, design, and build of artifacts that animate the social behavior of organizations. We develop a key design concept for IO SNIS and establish the design principles underlying the general artifact design and the specific design features that apply the design constructs to an exemplar IO social domain. This dissertation uses Action Design Research (ADR) approach within the Design Science Research (DSR) paradigm to formulate the research opportunity and anticipate a practice-inspired and theory-ingrained artifact. The researcher works with a practitioner team in the domain of mid-market private equity (MMPE) to explore the model and evaluate existing on-line inter-organizational artifacts to establish specific design features for an IO SNIS artifact. We find that the design principles can generalize from the IO SNIS Design Concept Model to other IO Social domains and that the design features can be used to build an instantiation of IO SNIS in the Private Equity domain.

Σε αυτήν την εργασία μελετήθηκε και σχεδιάστηκε ένας ψηφιακά ελεγχόμενος ταλαντωτής (DCO) με σκοπό GSM εφαρμογή. Οι συχνότητες λειτουργίας κυμαίνονται στο φάσμα 1.6GHz – 2GHz με βήμα 20kHz. Ο θόρυβος φάσης ποσοτικοποιείται στα -160dB/Hz σε 20 MHz απόκλιση. Ο έλεγχος του DCO γίνεται πλήρως ψηφιακά επιτρέποντας την υλοποίηση πλήρους ψηφιακού βρόχου κλειδώματος φάσης (ADPLL) και καθολικού system on chip design (SoC). Ο ταλαντωτής καταναλώνει 4,5 mWatt με 3,76 mA ρεύμα σε 1.2 V τροφοδοσία. / A Digitally Controlled Oscillator is studied and designed for GSM application. The operating frequencies are 1.6-2GHz with tuning range of 400MHz and finest step size 20 KHz. A fully digital control is achieved form where arises the opportunity for fabrication of an All-Digital Phase Locked Loop (ADPLL) and the whole system on chip (SoC). The proposed DCO core consumes 3.76mA from a 1.2V supply.

Internet-delivered programs based on cognitive behavior therapy (CBT) have during the past decade shown to work in an effective way for the treatment of depression. Due to its accessibility and independence of time and location, smartphone-based CBT might represent the next generation of digital interventions. Depression is an affective disorder that affects as many as 350 million people worldwide. However, with CBT, depression can be treated, but access to this treatment is scarce due to limited health care resources and trained therapists. As a result of this, health care could highly benefit from the use of smartphones for delivering cost-effective treatment that can be made available to a large part of the population who suffer from depression. One treatment that should be especially suitable for the smartphone format is behavioral activation (BA), since it has strong empirical support as well as the benefits of being flexible and rather simple. The overall aim of the thesis was to test and further develop a BA smartphone application, as well as to build a method for how this smartphone application could be used in a comprehensive and effective way in depression treatment. To fulfill this aim, four studies were conducted. The results showed that smartphones have the ability to be used in an effective way in the treatment of depression, including as an add-on to traditional face-to-face sessions. The results also showed that the smartphone format was experienced as a portable and flexible way of accessing the treatment – and thus could be more present in everyday life. In conclusion, there is reason to believe that smartphones will be integrated even further in society and therefore may serve an important role in future mental health care. Since the first indications reveal that depression can be treated by means of a supported smartphone application, it is highly possible that applications for other mental health problems will follow. Furthermore, in this thesis, the same smartphone application has been tested in three different ways and there is potential to apply smartphones in a range of other formats, such as in relapse prevention and as a way to intensify treatment during periods when needed. From a psychiatric research point of view, as my research group has been doing trials on guided internet treatment for more than 15 years, it is now time to move to the next generation of information technology – smartphones. / Internetbaserad kognitiv beteendeterapi (KBT) har under det senaste decenniet visat sig fungera effektivt i behandling av depression. På grund av dess tillgänglighet och flexibilitet i tid och plats har smartphonebaserad KBT potential att bli nästa generation av digitala behandlingar. Depression är en affektiv sjukdom som drabbar så många som 350 miljoner människor världen över. Med hjälp av KBT kan depression behandlas. Dock är tillgången till denna behandling knapp på grund av begränsade resurser i form av utbildade terapeuter. Därmed skulle sjukvården kunna dra stor nytta av användningen av smartphones för att leverera kostnadseffektiv behandling, som kan göras tillgänglig för människor som lider av depression. En behandling som kan vara särskilt lämplig för smartphone-formatet är beteendeaktivering (BA), eftersom den har starkt empiriskt stöd samtidigt som den är flexibel och relativt enkel. Det övergripande syftet med avhandlingen var att testa och vidareutveckla en smartphone-applikation baserad på BA, samt att bygga en behandlingsmetod för denna smartphone-applikation som skulle kunna användas för att effektivt behandla depression. För att uppnå detta syfte genomfördes fyra studier. Resultaten visade att smartphones kan användas på ett effektivt sätt i behandling av depression, bland annat som komplement till traditionella live-sessioner. Resultaten visade också initiala indikationer på att smartphoneformatet upplevdes som ett portabelt och flexibelt sätt att komma åt behandlingen - och därmed blev mer närvarande i vardagen.

Dans le contexte des applications mobiles, les contraintes de conception des chaînes d'émission toujours plus performantes et de taille réduite demandent de compenser la forte sensibilité des caractéristiques des antennes à leur environnement. En particulier, il est nécessaire de maîtriser l'impédance de l'antenne pour optimiser l'efficacité énergétique de la chaîne de transmission. Or, les solutions actuelles se montrent encombrantes. Dans cette thèse, plusieurs pistes basées sur l'implémentation de condensateurs variables ont été étudiées et ont conduit à la réalisation et la caractérisation de nouveaux dispositifs RF intégrés à même de participer à cet effort. Après une présentation du contexte et de l'état de l'art, nous proposons une étude de condensateurs variables basés sur la technique des capacités commutées. L'étude a permis la réalisation de deux condensateurs variables en technologie CMOS SOI 130 nm pour des applications d'adaptation d'impédance et d'antenne agile en fréquence. Un premier démonstrateur d'antenne fente agile en fréquence visant les bandes LTE situées entre 500 MHz et 1 GHz et utilisant ce type de condensateur a ensuite été réalisé puis validé. Un système d'accord permettant de corriger les désadaptations d'antenne a ensuite été étudié et a donné lieu à la réalisation de deux circuits intégrés en technologie CMOS SOI 130 nm. Le premier circuit est un détecteur d'impédance capable de fonctionner sur une gamme de puissance étendue de 0-40 dBm pour une plage de fréquences de 600 MHz-2,4 GHz. Le deuxième circuit intègre une version améliorée du détecteur avec un circuit d'adaptation variable autorisant la réalisation d'un système d'accord d'antenne autonome et compact représentant une avancée importante par rapport à l'état de l'art. / In the context of mobile applications, design constraints on always more performant and size-constrained emitting front-ends ask to compensate for strong sensitiveness of antennas characteristics to their environment. In particular, it is necessary to control the antenna impedance in order to optimize the energy efficiency of the transmitting front-end. Yet, current solutions are bulky. I this thesis, several ways based on the implementation of variable capacitors have been studied and have led to the design and characterization of new integrated RF devices that can participate to this effort. After a presentation of the context and the state-of-the-art, we propose a study of switched-capacitor-based variable capacitors. This study allowed the design of two variable capacitors in 130 nm CMOS SOI technology for impedance matching and frequency-agile antenna applications. Then, a first demonstrator module of a frequency-agile antenna aiming for 500 MHz-1 GHz LTE bands and using this type of capacitor has been designed and validated. A tunable system allowing the correction of antenna mismatch has then been studied and has led to the design of two 130 nm CMOS SOI integrated circuits. The first circuit is an impedance detector that is able to work on a 0-40 dBm power range and a 600 MHz-2.5 GHz frequency range. The second integrated circuit includes an improved version of the detector with a tunable matching network which both allow the fabrication of an autonomous, compact antenna tunable system showing significant progress relative to the state-of-the-art.

Physical objects with digital properties are being used more and more by the public. One such term for these artefacts include "the Internet of Things''. Most of these objects are often impossible to further modify or customise, and thus serve just the single purpose intended by their creators. This thesis explores the possibility of customising physical objects in order to provide an affordable and flexible way of interacting with them. A prototype, involving a mobile phone application (Android) and wireless sensor technology (NFC tags), was developed for the medical domain of speech and language therapy. The system, developed in close association with two therapists, allows the customisation of current speech and language exercise and associated material. It is designed to also assist with logging the patient interactions during the conduction of such exercises. The proposed solution has been tested and validated by medical experts, and its user interface evaluated by non-patient users.

Contactless automatic identification procedures which are called RFID systems (Radio-frequency Identification) have become very popular in recent years for transferring power and data. With the development of RFID technology, the demand of easy transmitting of short data packages has made NFC (Near-field Communication) technology wildly used especially in mobile applications. The communication between a mobile and a tag is achieved through a magnetic field generated by the mobile’s NFC interface. In order to get a maximal power transmission, the tag circuit is designed to operate at the resonance frequency of 13.56 MHz, which is equal to the operation frequency of the mobile’s NFC interface. As mutual inductances provided by different kinds of mobiles exist divergence, optimal power transfer cannot be reached every time. This thesis focuses on the optimization of power transfer during the communications between tags and mobiles with uncertain NFC coils. By incorporating a self-tuning parallel variable capacitance compensation circuitry the resonance frequency of an NFC tag circuit can be self-tuned to 13.56 MHz to ensure an optimal power transmission. This thesis presents both theoretical and experimental analysis of this improved self-tuning NFC circuitry in detail and demonstrates that by digitally tuning a parallel capacitor circuit, the energy transferred to an NFC tag can be optimized when facing different kinds of NFC-enabled mobile phones.

The Quantum Cascade Laser (QCL)-based terahertz-over-fibre (ToF) concept combines the strength of QCLs as ultra-wide bandwidth, high speed data sources, with the mature optical fibre technology. In this thesis, for the first time, by fusing multiple technologies, digitally selected, electronically-switchable ToF concept is experimentally demonstrated. Furthermore, the digital mode selection principle and electronic tuning mechanism provided by novel aperiodic distributed feedback (ADFB) multi-band filters are presented. For the development of electronically tunable ADFB lasers, a range of bound-to-continuum and chirped superlattice terahertz (THz) QCLs are measured across the frequency range 2.9 – 4.5 THz. The availability of these active materials allowed rapid assessments of the optimum design parameters for subsequent measurements. First, a range of photonic lattice-engineered lasers operating at 4.4 THz are characterized and key design parameters identified. Following this initial development, full electrical and spectral characterization of ADFB lasers operating at 2.9 THz are presented. The novelty of this work lies in the first-ever successful demonstration of discretely tunable QCLs, operating at six distinct THz frequencies. The ADFB technology was experimentally applied using various device geometries and gain dynamics. Toward this aim, results are presented for a Y coupled QCL architecture, showing that complex on-chip signal manipulation can be extended into the THz regime. In addition, it is demonstrated that ADFB technology provides broadband multi-channel optical filtering for the entire gain bandwidth. It is shown that discrete, purely electronic, tuning of simultaneous dual colour output can be achieved. Multi band optical filter functions derived from ADFB gratings possess highly nonlinear dispersion across the filter bandwidth and are found to modify the gain-induced, driving current-dependent continuous mode tuning. This thesis, therefore, presents a systematic experimental analysis of the dispersion engineered continuous fine-tuning in THz QCLs. In the final two chapters, the thesis presents, for the first time, transmission of tunable THz signals over standard single-mode optical fibre by up converting 2.9 THz QCL radiation via intra-cavity nonlinear mixing with an optical fibre-injected near-infrared (NIR) carrier in the 1.3 µm band. Discrete and continuous tuning technologies, as developed in chapters 3 – 5, are now successfully transferred to THz sidebands on the NIR carrier, extracted via a butt coupled single mode fibre and recorded using an optical spectrum analyzer. The major novel outcome of this thesis is the first demonstration of electronically tunable phase-matched points in a THz plasmon waveguide. The key breakthrough is the experimental confirmation of the photonic band-gap engineering of group velocity of THz signals – as both ‘fast’ and ‘slow’ switchable side bands are observed. Such novel nonlinear up-conversion of spectrally flexible THz signals may open up new possibilities for ultrafast THz telecom frameworks.