| 1. |
- Abdollahi Sani, Negar, et al.
(författare)
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All-printed diode operating at 1.6 GHz
- 2014
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 111:33, s. 11943-11948
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Tidskriftsartikel (refereegranskat)abstract
- Printed electronics are considered for wireless electronic tags and sensors within the future Internet-of-things (IoT) concept. As a consequence of the low charge carrier mobility of present printable organic and inorganic semiconductors, the operational frequency of printed rectifiers is not high enough to enable direct communication and powering between mobile phones and printed e-tags. Here, we report an all-printed diode operating up to 1.6 GHz. The device, based on two stacked layers of Si and NbSi2 particles, is manufactured on a flexible substrate at low temperature and in ambient atmosphere. The high charge carrier mobility of the Si microparticles allows device operation to occur in the charge injection-limited regime. The asymmetry of the oxide layers in the resulting device stack leads to rectification of tunneling current. Printed diodes were combined with antennas and electrochromic displays to form an all-printed e-tag. The harvested signal from a Global System for Mobile Communications mobile phone was used to update the display. Our findings demonstrate a new communication pathway for printed electronics within IoT applications.
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| 2. |
- Blomdell, Anders, et al.
(författare)
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Extending an Industrial Robot Controller-Implementation and Applications of a Fast Open Sensor Interface
- 2005
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Ingår i: IEEE Robotics & Automation Magazine. - 1070-9932. ; 12:3, s. 85-94
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Tidskriftsartikel (refereegranskat)abstract
- Many promising robotics research results were obtained during the late 1970s and early 1980s. Some examples include Cartesian force control and advanced motion planning. Now, 20 years and many research projects later, many technologies still have not reached industrial usage. An important question to consider is how this situation can be improved for future deployment of necessary technologies. Today, modern robot control systems used in industry provide highly optimized motion control that works well in a variety of standard applications. To this end, computationally intensive, model-based robot motion control techniques have become standard during the last decade. While the principles employed have been known for many years, deployment in products required affordable computing power, efficientengineering tools, customer needs for productivity/performance, and improved end-user competence in the utilization of performance features. However, applications that are considered nonstandard today motivate a variety of research efforts and system development to package results in a usable form. Actually, robots are not useful for many manufacturing tasks today, in particular those found in small and medium enterprises (SMEs). Reasonsinclude complex configuration, nonintuitive (for the shop floor) programming, and difficulties instructing robots to deal with variations in their environment. The latter challenge includes both task definitions and definition of motion control utilizing external sensors. The key word here is flexibility, and flexible motion control is particularly difficult since the user or system integrator needs to influence the core real-time software functions that are critical for the performance and safe operation of the system. We must find techniques that permit real-time motion controllers to be extended for new, demanding application areas.
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| 3. |
- Chedid, Michel, 1977-
(författare)
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Wearable Systems in Harsh Environments : Realizing New Architectural Concepts
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Wearable systems continue to gain new markets by addressing improved performance and lower size, weight and cost. Both civilian and military markets have incorporated wearable technologies to enhance and facilitate user's tasks and activities. A wearable system is a heterogeneous system composed of diverse electronic modules: data processing, input and output modules. The system is constructed to be body-borne and therefore, several constraints are put on wearable systems regarding wearability (size, weight, placement, etc.) and robustness rendering the task of designing wearable systems challenging. In this thesis, an overview of wearable systems was given by discussing definition, technology challenges, market analysis and design methodologies. Main research targeted at network architectures and robustness to environmental stresses and electromagnetic interference (EMI). The network architecture designated the data communication on the intermodule level - topology and infrastructure. A deeper analysis of wearable requirements on the network architecture was made and a new architecture is proposed based on DC power line communication network (DC-PLC). In addition, wired data communication was compared to wireless data communication by introducing statistical communication model and looking at multiple design attributes: power efficiency, scalability, and wearability.The included papers focused on wearable systems related issues including analysis of present situation, environmental and electrical robustness studies, theoretical and computer aided modelling, and experimental testing to demonstrate new wearable architectural concepts. A roadmap was given by examining the past and predicting the future of wearable systems in terms of technology, market, and architecture. However, the roadmap was updated within this thesis to include new market growth figures that proved to be far less than was predicted in 2004. User and application environmental requirements to be applied on future wearable systems were identified. A procedure is presented to address EMI and evaluated solutions in wearable application through modelling and simulation. Environmental robustness and wearability of wearable systems in general, and washability and conductive textile in particular are investigated. A measurement-based methodology to model electrical properties of conductive textile when subjected to washing was given.Employing a wired data communication network was found to be more appropriate for wearable systems than wireless networks when prioritizing power efficiency. The wearability and scalability of the wired networks was enhanced through conductive textile and DC-PLC, respectively. A basic wearable application was built to demonstrate the suitability of DC-PLC communication with conductive textile as infrastructure. The conductive textile based on metal filament showed better mechanical robustness than metal plated conductive textile. A more advanced wearable demonstrator, where DC-PLC network was implemented using transceivers, further strengthened the proposed wearable architecture. Based on the overview, the theoretical, modelling and experimental work, a possible approach of designing wearable systems that met several contradicting requirements was given.
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| 4. |
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| 5. |
- Johansson, Christian, et al.
(författare)
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Broadband dielectric characterization of a silicone elastomer
- 2007
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Ingår i: Journal of Electronic Materials. - : Springer Science and Business Media LLC. - 0361-5235 .- 1543-186X. ; 36:9, s. 1206-1210
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Tidskriftsartikel (refereegranskat)abstract
- The dielectric properties of an electronics grade silicone elastomer have been investigated in the frequency intervals 0.1 Hz to 1 MHz at −150°C to 100°C and from 7 GHz to 18 GHz at room temperature. The measurements were performed with a dielectric spectrometer for the low frequency range and with a waveguide setup for the high frequency range. The results are discussed in terms of performance and usability of the material in electronic packaging. Minor direct current (dc) conduction has been observed at high temperatures and is probably related to low levels (ppm) of ionic impurities.
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| 6. |
- Johansson, Christian, 1972-
(författare)
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High frequency electronic packaging and components : characterization, simulation, materials and processing
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Electronic packaging continues to move towards improved performance and lower cost. Requirements of higher performance, reduced size, weight and cost of both high density interconnects and high frequency devices have led to the search for new materials, material combinations, methods, processes and production equipment. Efficient technologies for producing high density interconnects, circuits for high frequency applications but also integrated packaging solutions for electrical and optical interconnects are looked for. Of emerging interest are methods and materials for ultra low cost printing of active components such as diodes and transistors. Large area panel processing (LAP) and sequential build-up technologies, using an UV-excimer projection lithography equipment and a photo-patternable ORMOCER® dielectric, is presented. The novel large area processing equipment enables 5 μm resolution patterning of surfaces up to a size of 610 mm x 610 mm. Large area panel processing enables miniaturized low cost & high performance electronics & photonics packaging. The advanced ORMOCER® dielectric and optical materials allow low temperature processing on low cost polymer substrates with low temperature stability such as FR4. Partitioning between cheap standard (lower) density interconnect in PCB substrates and high density interconnect in the upper thin film layers is possible in order to reduce the number of metal layers and arrive at an optimal performance cost ratio for specific applications. A demonstrator composed of four sequentially build-up dielectric layers have been deposited on a low cost FR4 epoxy substrate intended for high frequency applications. The dielectric layers consist of a photo-patternable ORMOCER® and the intermediate metal layers of sputtered Cu. The UV-patterning was performed with the LAP projection lithography equipment. The produced microstrip lines, ring resonators, vias, stacked capacitors and filters have been characterized at frequencies from 1 GHz to 40 GHz showing the potential of the new dielectric material for microwave applications. The investigation of the material properties were performed with a network analyzer where specially designed structures had been made for the characterization. Some of the measurements at high frequencies were also evaluated and compared with simulations. The measured results showed good agreement with the simulated response. The experimentally obtained high frequency properties of εr ≈ 3.05 and tan(δ) ≈ 0.024 at 10 GHz - 40 GHz would be sufficient for many applications. The dielectric properties of an electronics grade silicone elastomer have been investigated in the frequency intervals 0.1 Hz to 1 MHz and 7 GHz to 18 GHz. The low frequency measurements were performed with a dielectric spectrometer. The results are discussed in terms of performance and usefulness of the material in electronic packaging. The permittivity at room temperature in the frequency range 7 GHz - 18 GHz varied between 2.75 to 2.8 and the loss tangent between 0.018 to 0.033. The loss tangent in the GHz region at room temperature was considerably higher than in the Hz – MHz region most probably due to the activation of the inherent alpha relaxation in the material when reaching the GHz-range. A stepped impedance filter has been realized by changing the dielectric material, i.e. the permittivity instead of modifying the line width. It has been shown that the technology can offer alternatives to the standard approach and also that it is feasible to arrive at a denser packaging by combining low and high permittivity materials. The practical limit of the permittivity ratio is dependent on both available materials and on processability of these materials. The useful range of impedance ratios can be further increased by simultaneously using the ‘standard stepped impedance approach’ and the ‘variable dielectric approach’. A novel rectifying device has been realized by screen printing a silicon powder composite with the intention to use a low temperature low cost manufacturing method. Rectification at frequencies up to 1 MHz has been demonstrated but so far with a too high series resistance to be practically useful. With optimization of the device and composite concept, low temperature, ultra-low cost high speed printing of e.g. high frequency diodes on any substrate, may be viable.
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| 7. |
- Johansson, Christian, et al.
(författare)
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Microstrip stepped impedance filters with variable dielectric or variable width
- 2005
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194. ; 41:13, s. 745-746
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Tidskriftsartikel (refereegranskat)abstract
- A stepped impedance filter has been realised on a modified substrate. The change in impedance was achieved by varying the dielectric constant in the substrate while maintaining a constant width of the microstrip. In contrast to conventional stepped impedance filters the impedance is varied by the dielectric constant instead of the microstrip line width. The manufactured filter was measured and compared with an equivalent conventional stepped impedance filter. It is shown that the modified substrate technology could offer an alternative to the standard approach for the stepped impedance filter. In combination with new materials with a high permittivity the technology could also offer a denser package since the microstrip width could be controlled as desired.
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| 8. |
- Johansson, Christian, et al.
(författare)
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Microwave circuits in multilayer inorganic-organic polymer thin film technology on laminate substrates
- 2003
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Ingår i: IEEE Transactions on Advanced Packaging. - 1521-3323 .- 1557-9980. ; 26:1, s. 81-89
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Tidskriftsartikel (refereegranskat)abstract
- Requirements of higher performance, reduced size, weight and cost of high-frequency (HF) devices has led to the search for new: materials, material combinations, methods, processes and production equipment. Efficient technologies for producing HF-circuits and integral passives are looked for. Also of interest are integrated packaging solutions for high frequency electrical packaging and optical interconnects and packaging. Sequentially build up multi-layers have been deposited on a low cost FR-4 epoxy substrate. The dielectric layers consist of a photo-patternable inorganic-organic hybrid polymer (ORMOCER) and the metallization is Cu. An UV-exposure equipment enabling projection patterning with 5 μm resolution have been used. The produced microstrip lines, ring resonators, vias, stacked capacitors and filters have been characterized at frequencies from 1 to 40 GHz showing the potential of the new dielectric materials and processing technologies for microwave applications.
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| 9. |
- Johansson, Christian, et al.
(författare)
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Microwave circuits in multilayer ORMOCER® thin film
- 2002
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Ingår i: Proceedings IMAPS Nordic 2002. ; , s. 60-63
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A multilayer sequential build-up structure for the integration of passivemicrowave devices is presented. The different devices were processed byusing a photo-patternable polymer ORMOCER together with conducting layersof Cu on top of a FR-4 substrate. Microstrip and stub structures have beencharacterised at frequencies between 1 to 40 GHZ showing the feasibility ofusing this kind of material and build-up technology for microwaveapplications.
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| 10. |
- Johansson, Christian, et al.
(författare)
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Printable rectifying device using Si-composite
- 2008
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 44:1, s. 53-55
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Tidskriftsartikel (refereegranskat)abstract
- The R&D in finding low-cost manufacturing of electronics and electronic components is intense. One research route is aiming at roll-to-roll printing of organic electronics but the typically low mobility in organic semiconductors results in fundamental difficulties to fabricate, e.g., diodes for operation at high frequencies. A novel diode has instead been realised by screen-printing a silicon-powder composite with the intention to utilise the high mobility and the high operation frequency potential of silicon. The current against voltage (I-V) characteristics of the printed device reveal diode behaviour but so far with a too high ideality factor and resistance to be practically useful. By optimising device geometry, composite, and printing process low-cost printed, high frequency diodes (MHz-some GHz) may be viable.
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