Event program

Wednesday, 5/23/2012 3:00 PM - 6:30 PM, Nava 2, Hotel Admiral, Opatija Chair: Mile Ivanda (Ruđer Bošković Institute, Zagreb, Croatia)  Invited Paper  D. Ristic ( IFN – CNR , Trento, Italy), A. Chiasera (IFN – CNR , Trento, Italy), E. Moser (University of Trento, Trento, Italy), P. Feron (ENSSAT-FOTON, Lannion, France), G. Cibiel (CNES, Toulouse , France), M. Ivanda (Institut Ruđer Bošković, Zagreb, Croatia), G. Righini (IFAC-CNR, Firenze, Italy), M. Ferrari ( IFN – CNR , Trento, Italy) Erbium Doped Silica Microspheres for Lasing Applications  Silica microspheres were made by melting the tip of a standard telecom fiber. They were coated using a dip coating apparatus with a 70% SiO2 – 30 HfO2 sol-gel derived glass activated by 0.3 % mol of Er3+. The whispering gallery modes of the coated resonator were studied using a full taper – microsphere coupling setup. Upon excitation at 1480 nm sharp peaks in the wavelength range from 1540-1565 nm were observed pertaining to the lasing modes of the microresonator. Papers  1. M. Ivanda (Institut Rudjer Boskovic, Zagreb, Croatia), M. Balarin, O. Gamulin (Sveučilište u Zagrebu, Medicinski fakultet, Zagreb, Croatia), V. Đerek (Institut Ruđer Bošković, Zagreb, Croatia), D. Ristić (Consiglio Nazionale delle Ricerche - Istituto di fotonica e nanotecnologie , Trento (TN), Italy), S. Musić, M. Ristić, K. Furić (Ruđer Bošković Institute, Zagreb, Croatia), Z. Crnjak Orel (National Institute of Chemistry, Ljubljana, Slovenia) Porous Silicon Prepared by Electrochemical Etching of Silicon Eptaxial Layer  Porous silicon (PSI) samples were prepared by the electrochemical etching of n-type (111) epitaxialy grown silicon layer on n-type silicon (111) substrates, by varying the concentration of 48% HF in ethanol solution, and by varying the etching time. Electrical resistivity of epitaxial layer was ~2 Ω cm and of silicon substrate was ~ 0.015 Ω cm. Within the epitaxial layer, and on the substrate surface, the micro- and nano-pores of different sizes in dependence on HF concentration and etching time were obtained. With the etching time longer than 30 minutes, the epitaxially layer was detached from the substrate. The structural and optical properties of prepared samples were investigated by Raman and photoluminescence spectroscopy, field emission scanning electron microscopy (FE-SEM) and energy dispersive x-ray spectroscopy (EDS) spectroscopy. The FE-SEM images showed high density of micrometer sized pores on the epitaxial layers. After detaching the epitaxial layer, the substrate showed fine nanometer sized cobweb-like silicon structures whose morphology and density depend on HF concentration and etching time. The Raman spectra of such structures show transversal optical (TO) phonon band that broadens and red-shifts depending on the size of silicon nanostructures. The size distributions of the silicon basic structural units where determined by applying the phonon confinement model and were compared with those determined by FE-SEM. The intensity of phtoluminescence peak of such fine porous substrate shows the sensitivity on a degree of optical phonon confinement. 2. V. Đerek, M. Ivanda (Institut Ruđer Bošković, Zavod za fiziku materijala, Zagreb, Croatia), M. Balarin, O. Gamulin (Medicinski fakultet u Zagrebu, Katedra za fiziku i biofiziku, Zagreb, Croatia), M. Ristić, S. Musić (Institut Ruder Bošković, Zavod za kemiju materijala, Zagreb, Croatia), K. Furić (Institut Ruder Bošković, Zavod za fiziku materijala, Zagreb, Croatia), Z. Crnjak Orel (National Institute of Chemistry, Ljubljana, Slovenia) Formation and Luminescence of P-type Porous Polycrystalline Silicon  Luminescent porous silicon (PS) was obtained by galvanostatic electrochemical anodisation of p-type polycrystalline silicon (poly-Si) film in aqueous hydrofluoric acid (HF)/ethanol electrolyte. Poly-Si film was prepared and boron delta-doped on n-type silicon wafers by low pressure chemical vapor deposition (LPCVD) process. A voltage peak in galvanostatic mode was observed during anodisation, which was interpreted as etching through the p-n junction depletion layer barrier. Porous poly-Si surface morphology changed as a function of anodisation time. Scanning electron microscope (SEM) images have shown preferential etching and macro-porous Si formation along grain boundaries. Weak s-band photo-luminescence (PL) was measured in all samples, while Raman measurements indicated minimal or no confinement effects. 3. M. Očko (Institut za Fiziku, Zagreb, Croatia), S. Žonja (Fakultet elektrotehnike i računarstva, Zagreb, Croatia), M. Ivanda (Institut Ruđer Bošković, Zagreb, Croatia) Role of the Substrate and the Temperature of Deposition on the Properties of the TaxN Thin Films  We present an interim report on the investigations of the TaxN thin films deposited on the (100) Si wafers coated with a 140-nm thermal SiO2 layer. Our conclusions are based on the room temperature sheet resistance measurements, transport properties measurements from helium up to room temperature and on the Raman spectra analysis of the investigated series. In particular, we discuss a nonmonotonous concentration dependence of transport properties. This behaviour we attribute to a local minimum in the density of electronic states at the Fermi level calculated for the intermetallic Ta4N5 [1]. Such behaviour was not observed in other investigations on the transport properties of TaxN found in literature. Also our Raman spectra show some differences compared to other Raman investigations on TaxN. We ascribe these and other differences discussed to the substrate properties which were used in the preparation of these thin films. The overall properties of the TaxN deposited on the oxidized Si wafers are compared to the properties of the TaxN thin films deposited on sapphire. 4. S. Žonja (Fakultet elektrotehnike i računarstva, Zagreb, Croatia), M. Očko (Institut za fiziku, Zagreb, Croatia), M. Ivanda (Institut Ruđer Bošković, Zagreb, Croatia), T. Suligoj, P. Biljanović (Fakultet elektrotehnike i računarstva, Zagreb, Croatia) On the Application of Boron and Phosphorus Heavily Doped LPCVD Polycrystalline Silicon Thin Films as Thermoelectric Materials  Even in the metallic regime, heavily doped polysilicon has high thermopower, but since recently due its high resistivity combined with good thermal conductivity, silicon was not considered as a possile thermoelectric material. However, various reasons have encouraged investigations on polycrystalline silicon in order to enhance its TE properties. We discuss these reasons and give a short overview of the most promising results and works done in the field. We also present our incipient work on the LPCVD obtained polysilicon thin films annealed in various ways. The main important result we obtained so far is the high thermopower of a Si:B sample: +200 μV/K at room temperature, much higher than predicted for the common metals and the same as for Bi2Te3, the only thermoelectric material commercially used nowadays 5. V. Mitsa, R. Holomb, G. Lovas (Uzhgorod National University, Uzhgorod, Ukraine), M. Ivanda (Rudjer Boskovic Institute, Zagreb, Croatia), G. Rudyko, E. Gule, I. Fekeshgazi (Institute Physics of Semiconductors NASU, Kiev, Ukraine) Room Temperature Visible Luminescence in Wide Band Gap Chalcogenide Glasses  Visible photoluminescence was observed in binary g-As2S3, technologically modified g-GeS2(TiVj) and ternary glasses along (As2S3)x(GeS2)1-x line. PL maximum in g-As2S3 at 2.43 eV was assigned to band-to-band transitions and its position is in good agreement with value of optical band-gap edge absorption (Eo=2.4 eV). It is suggested that the peak at 2.2-2.3 eV in g-GeS2(TiVj) and GeS2-based ternary glasses may be attributed to presence of GeOx species. Complex PL peak at 2.6-2.7 eV in GeS2-based glasses was identified with germanium sulfur sites. 6. A. Berdinsky, I. Reshetnyak (Novosibirsk State Technical University, Novosibirsk, Russian Federation), J. Yoo (School of Advanced Materials Science, Sungkyunkwan University, Suwon, South Korea), E. Grayfer (Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences , Novosibirsk, Russian Federation), V. Makotchenko, V. Fedorov (Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russian Federation) Preparation and Research in Resistive-Strain Sensor Based on Transparent Conducting Graphene Sheets  The variation in resistance of multi-layered graphene films located on the flexible PET-substrate was researched. The deformation characteristics of graphene samples were obtained. The current through the samples is linearly dependent on deformation. The gauge factor of the flexible films was calculated. Effect of temperature on conductivity of graphene samples was investigated. 7. V. Fedorov (Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russian Federation), I. Mirzaeva, S. Kozlova, E. Grayfer (Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences , Novosibirsk, Russian Federation), M. Medvedev (Samsung Advanced Institute of Technology, Suwon, South Korea) Study of Electronic Structures of MoX2 (X = S, Se, Te): Arguments for Interactions of Molybdenum Atoms in Layers   The electronic structures of bulk and single layers dichalcogenides MoX2 (X = S, Se, Te) were studied by quantum chemistry method of electron localization function (ELF). Three-center interaction between the molybdenum atoms in the layers was found. The nature of this interaction depends on the type of chalcogen X, similar interaction is weaker for MoTe2. The observed effect supposes that observed interaction determines the stability of MoTe2 and may explain the nature of the existence of two structural modifications of MoTe2. 8. M. Pejovic, N. Nesic, M. Pejovic (University of Nis, Faculty of Electronic Engineering, Nis, Serbia) Investigation of Memory Effect by Measurement of Time Delay of Electrical Breakdown in Commercial Gas-filled Surge Arresters  Experimental data of mean values of breakdown voltage Ub of CITEL and SIEMENS gas-filled surge arresters (GFSA) obtained for voltage increase rates k=1-10 V/s with discretyzed dynamic method are presented in the paper. It has been shown that Ub = f (k) data are fitted very well by a straight line. The values of static breakdown voltage, which have been found at the intersection of the fitted line with Ub -axis ( k = 0 ), are in accordance with nominal values reported in datasheet and within tolerance of 20%. Based on the time delay of electrical breakdown data, it has been shown that the response time of GFSA made by SIEMENS is independent of relaxation time and is 60 µs. Response time of GFSA made by CITEL increases with relaxation time, which is a consequence of the decrease in concentration of positive ions and neutral active particles formed during breakdown. Response time decreases with the increase of applied voltage. This decrease is dependent on relaxation time in the case of GFSA made by CITEL, while this is not the case with SIEMENS made GFSA. 9. M. Pejovic, M. Pejovic, N. Nesic (University of Nis, Faculty of Electronic Engineering, Nis, Serbia) RADFETs as a Sensor and Dosimeter of Gamma-Ray Irradiation  Gamma-ray irradiation and post irradiation response at room and elevated temperature have been studied for RADFETs with gate oxide thickness of 100 nm with gate polarization during irradiation of 5 V as well as for RADFETs with gate oxide thickness of 400 nm with gate polarization of 0, 2.5 and 5 V. The response was observed on the basis of threshold voltage shift, ΔVT . Approximately linear dependence between ΔVT and absorbed dose was established. During the annealing at room temperature the RADFETs with the gate thickness of 400 nm and the gate polarization during irradiation of 2.5 V and 5 V shows the tendency in ΔVT decrease, while for 400 nm RADFETs with the zero gate polarization during irradiation and 100 nm RADFETs ΔVT remains approximately unchanged. Continued annealing at 120 oC leads to the decrease of ΔVT . For 100 nm RADFETs, ΔVT decreases to zero while for 400 nm RADFETs such decrease is considerably smaller. Thursday, 5/24/2012 9:00 AM - 1:00 PM, Nava 2, Hotel Admiral, Opatija Chair: Željko Butković (Faculty of Electrical Engineering and Computing, Zagreb, Croatia)    Papers   1. T. Knežević, T. Suligoj (FER, Zagreb, Croatia), A. Šakić, L. Nanver (ECTM-DIMES - TU Delft, Delft, Netherlands) Modelling of Electrical Characteristics of Ultrashallow Pure Amorphous Boron p+n Junctions  Diodes fabricated by a pure amorphous boron (PureB) deposition technology show outstanding performance. Depositing a PureB-layer on Si at temperatures from 500 - 700ºC creates an effective p+-layer at the interface and ultrashallow p+n-junctions less than 10 nm deep can be made. The PureB layer can also be used as an emitter region in pnp bipolar transistors having a high effective emitter Gummel number (GE) that appears to be related to the properties of the amorphous boron layer. In this paper, we suggest a wide-bandgap model of the amorphous boron layer to explain how its properties can lead to a suppression of the electron injection from the base into the emitter region thus giving the high GE. The presence of trap states in the bandgap of amorphous boron layer is also considered. They could reduce the majority carrier concentration and change the mobility in the layer contributing to a decrease of GE. It is concluded that the wider bandgap together with the trap states in the bandgap of amorphous boron layer could account for the high emitter Gummel number. 2. V. Tudić, L. Majdandžić, J. Groš (Karlovac University of Applied Sciences, Karlovac, Croatia) Model Optimization of Nanocrystalline Si:H Thin Film Solar Cells  Photovoltaic properties of nanocrystalline (nc-Si:H) heterojunction in intrinsic thin film single junction solar cells with the structure of TCO/p-a-SiC:H/i-nc-Si:H/i-a-Si:H/n-a-Si:H/AZO was studied by a computer modeling software AMPS-1D in this paper. Due to spectral response of solar cells with the examined nc-Si thin films as active elements showed a narrower spectral distribution and a blue shift comparing to pure amorphous solar cells. The results were higher efficiency than amorphous cells due to higher optical gap (higher output voltage) and better fil factor (higher mobility). 3. D. Babic, Q. Diduck (Group4 Labs, Inc., Fremont, United States), J. Smart (Group4 Labs, Inc., New York, United States), D. Francis, F. Faili, F. Ejeckam (Group4 Labs, Inc., Fremont, United States) Measurement of Thermal Boundary Resistance on AlGaN/GaN HEMTs Using Liquid Crystal Thermography  Liquid Crystal Thermography (LCT) is commonly used for hotspot identification and peak-temperature measurement in electronic devices. We use LCT to characterize GaN/Si and GaN/SiC high-electron mobility transistors and extract the thermal boundary resistance between the GaN epilayers and the substrate on these transistors. 4. J. Kundrata, A. Barić (UNIZG - FER, Zagreb, Croatia) Design of a Planar Inductor for DC-DC Converter on Flexible Foil Applications  This paper presents the design of a planar inductor for a DC-DC converter for flexible foil applications. The design challenges related to the flexible foil structure and the DC-DC converter requirements are analysed. The main design challenges are due to the constraints on the inductor physical size, the proximity of a conductive plane to the inductor and very high operating frequency of the DC-DC converter. The methodology of the inductor design is based primarily on EM simulations of the inductor structure and on the evaluation of the simulation results in the context of the resulting lumped-element electrical model. The simulations are verified by measurements of the inductors processed on the FR4 substrate which presently emulates the flexible foil substrate. 5. M. Jenko (Faculty of mechanical engineering, University of ljubljana, Ljubljana, Slovenia) Development of an Analog Simulator for the Transient Analysis of Electric Circuits, with the Aim of Teaching Circuit Phenomena by Simulation of Equations  Teaching electric circuit theory involves the use of Ohm’s and Kirchhoff’s laws; branch, mesh and node analysis, as well as AC analysis and transient analysis. The latter gives the most comprehensive insight into circuit behavior. When analytical transient circuit analysis is used, one needs to solve the differential equations that describe the circuit behavior. Electrical engineering students often find this difficult. Alternatives to the mathematical analysis are: a) the simulation of the given problem with a commercial circuit simulator, and b) building a physical circuit, the behavior of which can then be observed and analyzed. These approaches are most productive when optimizing the behavior of a circuit, but they can easily add their own noise to the circuit study. The presented approach for the effective transient analysis is by simulating equations. The circuit in question is analyzed using Kirchhoff’s laws with reference to specific time slices. The equations describing circuit components that store energy (capacitors, inductors) are then used to connect the consecutive time slices. The coding of equations for a given circuit allows students to gain a thorough understanding of the circuit’s workings. Test cases show that results match perfectly between the simulation of equations and the analytical results from different RLC example circuits. 6. F. Pepe, A. Bonfanti, A. Lacaita (Politecnico di Milano, Milano, Italy) A Fast and Accurate Simulation Method of Impulse Sensitivity Function in Oscillators  This paper presents a novel and simple simulation method to evaluate the impulse phase response of an oscillator. The technique, based on the linear-time variant (LTV) analysis of oscillators, computes the phase response in the frequency domain. It can be performed by means of periodic AC (PAC) or periodic transfer function (PXF) analysis available in commercial circuit simulators (Spectre, Eldo, etc.). This method overwhelms the classical simulation method based on the injection of charge pulses along the oscillator period and transient analysis both in term of speed and precision. The good accuracy of the frequency-domain method has been verified in two practical case studies, evaluating the 1/f3 phase noise in a classical Van der Pol oscillator and estimating the injection locking range in a ring oscillator-based frequency divider. 7. V. Čeperić, A. Barić (Faculty of Electrical Engineering and Computing, Zagreb, Croatia) A Brief Overview of the Black-Box Behavioural Modelling of Electronic Circuits for Transient Simulations  Transient simulations of electronic circuits in the time domain can be one of the most complex tasks that engineers encounter in the field of electronics and microelectronics due to two main problems: slow speed of SPICE transistor level circuit simulations and limited accuracy of classic techniques for improving speed of circuit simulations. The black-box approach to behavioural modelling of electronic circuits, although very challenging, is particularly interesting due to possibility of fast and accurate simulations and that is the reason why black-box modelling techniques are gaining more and more attention in industry and academic community. The goal of this professional paper is to give an overview of the topic, identify current state-of-the-art and give suggestions for the future research in the area of black-box behavioural modelling of electronic circuits in the time-domain. 8. A. Broznić, R. Blečić, A. Barić (Fakultet elektrotehnike i računarstva, Zagreb, Croatia) A 2.5-GHz GaN Power Amplifier Design and Modeling by Circuit-Electromagnetic Co-Simulation  In this paper a 2.5-GHz GaN power amplifier is presented. The amplifier is designed to achieve unconditional stability in the frequency range from DC to 6 GHz. The circuit-EM co-simulation model of the complete amplifier, including transistor model, passive components, connector model and the EM model of the critical parts of the design is created. The impact of each component is addressed. The amplifier is processed and measured, the measurements are compared to simulations and a good agreement is achieved. The amplifier parameters power added efficiency (PAE), drain efficiency (DE) and IP3 are measured and compared to results published in open literature. 9. C. Popa (Faculty of Electronics, Telecommunications and Information Technology, Bucharest, Romania) Pseudo-Exponential Computational Circuit With Improved Accuracy and Frequency Response  A new higher-order CMOS current-mode pseudo-exponential circuit will be presented. The advantage of the circuit with respect to the previous reported similar ones is the smaller value of the limited expansion error obtained by using a higher order approximation of the exponential function. The circuit presents the important advantage of the independence of the output current on technological parameters. Due to the strong inversion operation of all MOS transistors and to the current-mode operation of the circuit, the circuit frequency response can be strongly improved. The second-order effects will be taken into account for evaluating the total error of the circuit core, resulting an additional error summed to the error caused by the neglecting of the superior-order terms from the exponential function Taylor series expansion. The circuit area is relatively small due to the exclusively utilization of MOS transistors. 10. B. Mrković (Tehnoalarm d.o.o., Zagreb, Croatia), M. Ašenbrener (Sveučilište u Rijeci, Rijeka, Croatia) The Simple CMOS Negative Capacitance with Improved Frequency Response  The negative capacitance circuits are very interesting analog building blocks with many possible applications like compensation of undesired parasitic capacitance, bandwidth enhancement of amplifiers, equalization filters design without passive inductors, etc. This paper presents a method for improving CMOS floating negative capacitance frequency response. As the negative capacitance is generated with the simple and known negative impedance converter (NIC), proposed method is applicable for negative inductance and resistance also. The proposed method is simulated and verified using standard 0.35µm and 0.18µm CMOS processes. 11. J. Žilak, M. Koričić, T. Suligoj (FER, Zagreb, Croatia) Impact of Bipolar Transistor Parameters on the Characteristics of the Double-Balanced Mixer  Impact of integrated bipolar transistor parameters on the double-balanced Gilbert mixer performance is analyzed. Used bipolar transistor Gummel-Poon model is based on Horizontal Current Bipolar Transistor (HCBT) integrated technology. Intermodulation distortion and conversion gain are analyzed with harmonic balance simulations. Due to the flexibility of HCBT technology, transistor parameters can be adjusted and their impact on circuit characteristics is examined. Analysis started at lower level, where distortion is examined on common emitter amplifier, then it is expanded on the whole mixer where the influence of the each circuit part on distortion is examined. Achieved values of input third-order intercept point (IIP3) of 18 dBm and conversion gain of -3.3 dB for mixer with default transistor parameters could be found in commercial mixers. Parameter optimization gives a 4-5 dBm increase of IIP3 with small conversion gain decrease of -0.5 dB. The linearity increase depends on the mixer operating frequency. 12. D. Bundalo (Faculty of Philosophy, Banja Luka, Bosnia and Herzegovina), Z. Bundalo, F. Softic (Faculty of Electrical Engineering, Banja Luka, Bosnia and Herzegovina), M. Kostadinovic (Faculty of Traffic and Transportation, Doboj , Bosnia and Herzegovina), D. Pasalic (Telecom of Srpska, Banja Luka, Bosnia and Herzegovina) Logic Circuits with High-Impedance Output State for Interconnection of Ternary and Binary CMOS Digital Circuits and Systems  Possibilities and principles for interconnection of CMOS ternary circuits and systems with binary common buses in digital circuits and systems are considered and described in the paper. Proposed are circuits with high-impedance output state for interconnection that perform signal conversion from ternary to binary CMOS digital system. General structure and general principle for design of such circuits are shown and described first. Then, the concrete circuit solutions are proposed and described. The circuits with one ternary input and the circuits with any number of ternary inputs are given and described. All proposed circuits were analyzed by computer simulations. All considerations, descriptions and conclusions were confirmed by simulation. 13. D. Vinko, T. Švedek (ELEKTROTEHNIČKI FAKULTET OSIJEK, OSIJEK, Croatia), A. Barić (Fakultet elektrotehnike i računarstva, Zagreb, Croatia) Limitations of the CVSL Driver as Voltage Level Booster for Switching Capacitors in High-Gain Charge Pumps  High-gain charge pumps use MOS switches to rearrange the topology of the circuit in the adjacent half periods of clock signals. This enables the charge pump circuit to achieve high gain of the output voltage. For the proper operation of such designs MOS switches must be adequately controlled to enable fast charge transfer while turned “on” and to prevent leakage current while in “off” state. This paper presents the usage limitations of Cascode Voltage Switch Logic (CVSL) circuit as a control circuit for MOS switches. The operation of the CVSL driver is discussed and the negative effects of the capacitive load associated with CVSL output node are analyzed. 14. J. Podržaj (IskraLAB d.o.o., Šempeter pri Gorici, Slovenia), A. Sešek, J. Trontelj (Faculty of Electrical Engineering, Ljubljana, Slovenia) Intelligent Power MOSFET Driver ASIC  This paper focus is on an ASIC design for power MOSFET driver with an intelligent current driving technique which optimizes the performance and efficiency of the driving single or more in parallel connected power MOSFETs. The efficient and robust driving of the power MOSFET gate is, beside the current driving techniques, also supported with the adjustable rise and fall times parameters of the driving signal. The design of the ASIC power MOSFET driver includes the implementation of safety functions which are essential for providing a higher level of robustness and reliability of the controlled power MOSFET transistor as also of the entire power MOSFET system. The introduced mixed-signal designed ASIC is used as a single chip solution without any extra additional electronic components which increases the integration density, reliability and reduces the costs of the power system. Thursday, 5/24/2012 3:00 PM - 7:00 PM, Nava 2, Hotel Admiral, Opatija Chair: Dubravko Babić (Faculty of Electrical Engineering and Computing, Zagreb, Croatia)   Invited Paper  B. Malnar (Intel GmbH, Braunschweig, Germany) Synthesis Flow for Designing a High Performance Microprocessor  This paper describes the methodology for the automated synthesis flow used for a high-performance microprocessor project at Intel. The flow presents a standard method of automatically translating the RTL description of the microprocessor to placed and routed gates. The flow optimizes the design for timing and power, while ensuring that the final netlist is logically equivalent to the RTL and that all of the backend checks and rules are satisfied (for example noise, many electrical rules, routing rules, metal reliability, etc). The typical inputs to the flow are RTL, timing constraints and floorplan description, while the typical outputs are the netlist and layout. The netlist and layout are used as inputs to the other tools for logical and physical verification of the design. Papers  1. D. Kirasić, D. Basch (Fakultet elektrotehnike i računarstva, Zagreb, Croatia) Reconfigurable Processor Architectures: Varieties and Representations  Reconfigurable processors combine the speed of application specific integrated circuits (ASIC) and the universality of classical digital processors by means of adaptability to currently executed code. There is a great number of varieties in today's reconfigurable processor architectures. The architectures differ significantly and there is a need for efficient method of comparing them and a way of defining representation format for different architectures. The architecture representation is usually used in software tools such as compilers and simulators for reconfigurable processors. The main aim of this paper is to propose various comparison criteria for different reconfigurable processor architectures and to give an overview of the representation methods for them. The main contribution of this paper is a proposal of the new ontology-based representation for reconfigurable processor architectures. 2. V. Dogan, M. Brkić (Faculty of Technical Sciences, Novi Sad, Serbia), N. Vukoje (Novilog, Novi Sad, Serbia), G. Mančić (Hotwell Ges.m.b.H , Klingenbach, Austria), M. Živanov (Faculty of Technical Sciences, Novi Sad, Serbia) A Novel Solution for Realisation of Data Transfer in Borehole Measurement Systems  In the borehole measurements it is generally beneficial to be able to conduct a larger number of measurements at the same time, which results in large amounts of data that has to be send from measurements probes to surface. Most borehole systems as transmission line use monoconductor electromechanical cable with small cut-off frequency. In this paper a novel method of data transfer over monoconductor electromechanical cable is presented. This method uses HDB3 (high density bipolar of order 3) line encoding and system for reconstructing of the received signal. It achieves higher bit rates than usual methods used in borehole systems. Advantages of this method are discussed and system based on this method is presented in this paper. System is realized and measurement results are presented. 3. M. Glavinić Pecotić (Siemens d.d., Zagreb, Croatia), G. Molnar, M. Vučić (University of Zagreb, Faculty of Electrical Engineering and Computing, Zagreb, Croatia) Design of CIC Compensators With SPT Coefficients Based on Interval Analysis  The simplest multiplierless decimation filter is the cascaded-integrator-comb (CIC) filter. However, the magnitude response of this filter has a high passband droop, which is not tolerable in many applications. The droop can be reduced by the filter called CIC compensator. In this paper, we present a method for the design of finite-impulse-response CIC compensators whose coefficients are expressed as the sums of powers of two (SPT). The method is based on the minimax error criterion. To obtain the SPT coefficients, we use a global optimization technique which is based on the interval analysis. The proposed compensators are multiplierless and result in wide compensation bands. Therefore, they are suitable for application in software radio receivers operating with low decimation factors. 4. I. Mrčela, V. Šunde, Z. Benčić (Fakultet elektrotehnike i računarstva, Zagreb, Croatia) Method for Selection of Switches for Power Electronic Converters  This paper describes the educational method for selection of semiconductor switches based on the results of simulated behaviour of the converter circuit with ideal switches. The current-voltage relations on the converter circuit ports and the converter topology determine the requirements for the static and switching characteristics of semiconductor switches. Selection of the switches is illustrated with examples of a fullbridge rectifier with a resistive-inductive load, a buck converter with a resistive-inductive load and a resonant inverter. 5. T. Čihak (KONČAR Institut za elektrotehniku, Zagreb, Croatia), Ž. Jakopović (Fakultet elektrotehnike i računarstva, Zagreb, Croatia) Simple Control System for Power Converter Connecting Electrochemical Dual-Layer Capacitors to DC Link  Electrochemical dual layer capacitors, also known by their market names Supercapacitors and Ultracapacitors are perspective technology for many uses, for instance in power saving circuits for electric propulsion systems, short-term energy storage systems, systems for extending battery lifetime and other similar uses. Although they can be used connected directly to a power converter DC link, in most cases they are connected to the DC link through a separate power converter. In use, such an EDLC and power converter assembly, due to EDLC specifics, must reliably operate in numerous operating points, unlike a typical power electronic converter. Such a power converter operation entails many control issues. Some of them are considered in this paper. 6. L. Olvitz, D. Vinko, T. Švedek (ELEKTROTEHNIČKI FAKULTET OSIJEK, OSIJEK, Croatia) Wireless Power Transfer for Mobile Phone Charging Device  With an ongoing trend in mobile phone charger standardization, the next step to make the charging process even more user friendly is to eliminate the physical cable connection between the charger and the mobile phone. To achieve a wireless charging of a mobile phone, a wireless power transfer system must be designed. One such system is presented in this paper. Theory of the wireless power transfer is explained and a functional wireless charger device is realized. Presented wireless charger device has the power transfer capability of around 1W at a maximum distance of 2.5 cm, which is sufficient to charge a regular mobile phone. 7. M. Brkić, M. Lukić, J. Bajić, B. Dakić, M. Vukadinović (Faculty of Technical Sciences, Novi Sad, Serbia) Hardware Realization of Autonomous Robot Localization System  One of the most important problems in autonomous robot guidance is their localization, i.e. determining their physical location within their operating area. In this paper we describe hardware realization of triangulation method for localization of wheeled autonomous robot that operates on flat rectangular surface. Triangulation is a method of calculating location of robot relative to 3 landmarks (beacons) located on fixed predetermined positions. This method usually needs measurement of distances between robot and beacons, to be able to calculate robot position. Different approach based on angle measurement is described in this paper, advantages of this method are discussed and details of hardware realization are explained. System is realized and tested, measurement results are given. 8. H. Lee (E2S Company Ltd., Seoul, South Korea), H. Ryu (Korea Electric Power Research Institute, Daejeon, South Korea), J. Kwon (University of Seoul, Seoul, South Korea), G. Park, I. Kim (Korea Gas Safety Corporation, Siheung, South Korea), H. Kim (University of Seoul, Seoul, South Korea) Development of Cost-Effective Redundant Digital Excitation Control  In this paper, the developed digital excitation control system was evaluated to get the strength of operating situations in the small power plant. Recently, most automatic voltage control systems for big power plants employ a quick response and stationary excitation technology. But cost of older excitation systems has been prohibitive for redundancy. And they add much complexity to the system relative to wiring and interconnection. To solve these problems, the new redundancy digital excitation control system was developed. This system ensures adequate steady-state, dynamic reactive reserves, and zero tolerance. In addition, it provides protective features for the generator such as over flux limiting and field current limiting. Finally, the performance of this digital excitation control system was verified in a gas turbine of a coal-fired plant. 9. J. Dong, W. Gaberl ( institute of Electrodynamics, Microwave and Circuit Engineering,Vienna University of Technology, Vienna, Austria), K. Schneider-Hornstein, H. Zimmermann (institute of Electrodynamics, Microwave and Circuit Engineering,Vienna University of Technology, Vienna, Austria) A Fully Integrated Multicolor Photoreceiver  A fully integrated multicolor photoreceiver is presented, which combines a triple junction photodetector, three transimpedance amplifiers and three output drivers in a single chip. Gain and offset can be adjusted individually for each path. The fiber (glass fiber or POF) can be directly coupled onto the light sensitive area of the integrated receiver. The usable wavelength range is from 400nm to 900nm. The triple junction photodetector is designed based on the effect that light with longer wavelength can penetrate deeper into silicon than light with shorter wavelength. The three vertically stacked photodiodes can accurately and simultaneously convert light with different colors into different currents. The single chip photoreceiver is fabricated in standard 0.6 µm CMOS technology using an epi-wafer without any process modifications. Thus it can be realized cheap and with minimal packaging effort. In addition, the presented device can pave the way for a single visible WDM receiver – a solution optimal for high speed POF transmission systems. Based on the simulation results, we find that the designed photoreceiver can meet requirements of both color detections and a relatively high transmission rate up to 200 Mb/s per color. 10. J. Bajić, B. Dakić, D. Stupar, M. Slankamenac, M. Živanov (Faculty of Tehnical Sciences, Novi Sad, Serbia) The Frequency-Modulated Reflective Color Sensor  In this paper frequency-modulated sensor for color detection based on reflective color sensing is proposed. The sensor has a RGB LED and a phototransistor. Red, green and blue LEDs are exited at different frequencies. In this way detection of the reflected signal is achieved with only one photodetector and three bandpass filters. Color information from the sensor is obtained using digital signal processing of frequency modulated signal on a personal computer (PC). The signal is transferred to the PC using analog to digital converter on a PC sound card. 11. J. Bajić, D. Stupar, J. Tomić, M. Slankamenac, A. Joža, M. Živanov (Faculty of Tehnical Sciences, Novi Sad, Serbia) Implementation of the Optical Beam Profiler System Using LabVIEW Software Package and Low-Cost Web Camera  In this paper a realization of the optical beam profiler system based on a low-cost web camera and great capabilities of LabVIEW software package is presented. The system provides possibilities of measuring, capturing, displaying, and recording various parameters of the optical beam, such spatial profile, beam quality, intensity measurement and so on. Implemented software enables various types of image processing, which makes measuring easier and more accurate. The applications of the developed system include: laser monitoring, nonlinear optics, far-field measurement, education and so on. Friday, 5/25/2012 9:00 AM - 1:00 PM, Camelia 1, Grand hotel Adriatic, Opatija Chair: Davor Vinko (Faculty of Electrical Engineering, Osijek, Croatia)  Papers  1. R. Resmi, M. R. Baiju (College of Engineering,Trivandrum, Thiruvananthapuram, India) Performance Analysis of a Tunable Piezoelectric Actuator Based MEMS Resonator  In this paper, the quality factor of a tunable piezoelectric actuator based MEMS resonator is analyzed. The piezoelectric effect is the transfer of electric energy to mechanical energy and vice versa which arises in many crystalline materials. A tunable piezoelectric actuator based resonator consists of a cantilever beam actuated by a piezoelectric device mounted on the beam. A piezoelectric device can actuate a cantilever beam by applying an AC voltage over the device. The cantilever beam itself has resonant modes that causes peaks in the vibration when the frequency of the applied voltage matches the resonance frequency of each mode. If another piezoelectric device is attached to the cantilever, it is possible to tune the resonance by connecting that device to a passive external circuit. The multilayered structure created in a tunable piezoelectric actuator causes a discontinuity in thermal transport across the structure, altering the thermoelastic behaviour of the resonator. Applying the principle of superposition, the overall frequency dependent quality factor of tunable piezoelectric actuator can be calculated and it shows two minima compared to that of simple fixed-fixed beam resonators. The Q Factor analysis of the actuator is done by a high end software COMSOL Multiphysics. 2. S. Preradovic (Nitero Pty Ltd, Melbourne, Australia), A. Menicanin (Institute for Multidisciplinary Research, Belgrade, Serbia) Chipless Wireless Sensor Node  A wireless sensor node based on a chipless RFID tag with integrated sensor element is presented. The chipless tag is multiresonator-based and encodes data as spectral signature. The sensor element is attached to a dedicated resonator of the chipless node. Two types of sensor elements are used – resistive and capacitive. The resistive sensor output changes the Q factor of the spiral resonator effectively changing its insertion loss at the resonant frequency. The capacitive sensor output changes the spiral resonator’s resonant frequency. The chipless wireless sensor node can be used in various automated monitoring applications. 3. Ž. Mihajlović, V. Milosavljević, N. Maoduš, V. Rajs, M. Slankamenac, M. Živanov (Fakulty of Technical Sciences, Novi Sad, Serbia) System for Monitoring Concentration of NO2 and CO Gasses on Landfill Sites  This paper describes hardware system for monitoring gas migration inside of borehole wells on landfill site. Hardware unit is designed to show the applicability of such device in terrain conditions. Therefore, we used easily available and cheap sensors for gases such as nitrogen dioxide and carbon monoxide. The solution can easily be expanded with other types of gas sensors, if necessary. Temperature and humidity sensors are installed for the measurement compensation that depends on these parameters. The device includes GPRS/GPS modem that allows sending data to server application for further processing. Also, the control of device via server application and SMS service has been implemented. Integration of microcontroller inside sensor system allows implementation of automatic monitoring and support for management of the outer actuators and alarms. Simple client application displays the results of measurements in real time, if necessary, or in the adjustable time intervals, which is useful for battery supplied operation. 4. G. Park, Y. Kim, I. Kim (Korea Gas Safety Corporation, Siheung-si, South Korea), H. Kim (University of Seoul, Seoul, South Korea) A Positive Study on Effective Gas Safety Management using Wireless Sensor Network  In this paper, we developed and positively tested the effective gas safety management system using wireless intelligent gas safety appliances to monitor gas flow and pressure, earthquake in a micom-gas-meter, to check combustible gas leaks and temperature (upper 100℃) in an automatic extinguisher and to detect smoke and CO gases. Then our system take safety measures such as cutoff, warning and messaging to protect a serious risk if results of event are abnormal, communicate with a wall-pad including a gateway with Jennic ZigBee network in buildings and inform those risky events to user via the safety management program in our web server. Also, the built-in every inner cutoff valve in intelligent gas meters and the middle valves in automatic extinguishers are operated automatically if irregular events are occurred and signal to the controlling wall-pads to a managing server. 5. Ľ. Ovseník, J. Turán, M. Tatarko (Department of Electronics and Multimedia Communications, Faculty of Electrical Engineering and Infor, Košice, Slovakia) Availability and Reliability of FSO links Estimation from Measured Fog Parameters  This work is focused on last mile system called FSO (Free Space Optics). In this communication system, the propagation media is air. Communication systems working in free environment are very popular and establishing of connection is very easy. But on the other hand a number of phenomena in the atmosphere such as scattering, absorption and turbulence cause a large variation of receiving power and laser beam attenuation. The influence of absorption and turbulence can be significantly reduced by an appropriate design of FSO link. But the visibility has the main influence on quality of the transmission channel. Thus, in typical continental area where rain, snow or fog occurs is important to know their values. Free space optics is line of sight technology. This article gives us a detail description of the instrument for measuring weather conditions such as the density of fog, humidity and temperature. From the measured data is available to calculate a visibility which is the main factor of the availability and reliability of FSO link. 6. A. Badnjevic, E. Beganovic (New Technology Ltd, Sarajevo, Bosnia and Herzegovina), G. Šehić (New Technology Ltd, Tuzla, Bosnia and Herzegovina) Disadvantages of Methods for Power Indication During Treadmill Exercise for Ergospirometry Test  This paper will show basics and importance of ergospirometry. Parameters that affect the patient while running and walking will be shown together with principle for determining the Work Load during the test. The essence of the study and research was to analyze various formulas implemented for determining the power [Watt] on the basis of patient training on the treadmill during the ergospirometry performance test. Four types of calculation in methods of obtaining power (WorkLoad) that occur in the majority of device manufacturers for ergospirometry were analyzed for the load during the ergospirometry test. It is shown that Jaeger formulas compared to ATS, Bruce and Modified ATS Formula, have the best results for different conditions of the experiment, and that they fit in the most testing conditions. This research has great importance for doctors that interpretate results of test, since using the best possible formula for determining Work Load is of critical importance and it can have influence on determining need for further tests that sometimes include invasive surgery. Paper also displays shortcomings of mentioned formulas and can be used as a reference when determining which formula is to be used for parameter calculation in a variety of situations. 7. M. Jordanic, R. Magjarevic (Faculty of Electrical Engineering and Computing, Zagreb, Croatia) Estimation of Muscle Fatigue During Dynamic Contractions Based on Surface Electromyography and Accelerometry  Common non-invasive measurements of muscle fatigue during dynamic contractions are based on the surface electromyography (SEMG). However, these measurements include movement artefacts such as the change of muscle length and the movement of electrodes. These artefacts significantly contribute to the non-stationary properties of the measured SEMG signal. Consequently, the measurements of the muscle fatigue employ various sensors and signal-processing methods. In this paper, we present a method for the estimation of the fatigue which uses an accelerometer to determine the SEMG segments within which the movement artefacts are resolved and the widesense stationarity holds. The fatigue is then estimated by the median frequencies of their power spectra. To illustrate the features of the proposed method, we apply it to the biceps curl exercise. 8. M. Cifrek (Fakultet elektrotehnike i računarstva, Zagreb, Croatia), S. Peharec (Poliklinika za fizikalnu medicinu i rehabilitaciju "Peharec", Pula, Croatia), H. Džapo, T. Pribanić (FAKULTET ELEKTROTEHNIKE I RAČUNARSTVA, ZAGREB, Croatia), S. Mrvoš (RIZ-Odašiljači d.d., ZAGREB, Croatia) Biomechanical Scale for Dynamic Human Body Posture Analysis  Dynamic monitoring of patient body weight distribution in biomechanics laboratory can provide useful information for research and diagnosis purposes. The examinee can be subjected to different conditions, either standing still or doing a set of predefined exercises. Human locomotor system maintains the body balance in a complex manner, thus resulting in very small weight distribution perturbations which can provide a better insight in the patient state and serve as an excellent practical diagnostic tool. This paper describes an implementation of biomechanical scale designed to enable a high resolution dynamic body weight distribution measurement, along with monitoring of the angle and the distance between feet in the real-time. 9. B. Somek (FER, Zagreb, Croatia), J. Ostojić (Ministarstvo socijalne politike i mladih, Zagreb, Croatia), M. Krhen (FER, Zagreb, Croatia) High Quality Hearing Aids  The need for hearing aids is growing and manufactures are coming up with new technologies(digital and DSP) to make thise devices more atractive and effective. Users of those deviceswho were not always hearing impairments are divided into several groups: audio masters,audio engineers, young people exposed to excessive noise levels, older people, and persons with disabilities. The procedures of getting audiogram were analyzed, as well as the ways of setting (DSP) device characteristics related to individual patients. AB tests are carried out, and on the basis of obtained results, individual processes or devices that can enable people with hearing loss well music listening were evaluated (mono, hi-fi stereo, surrounding sound) 10. D. Šoštarić, D. Vinko, T. Švedek (ELEKTROTEHNIČKI FAKULTET OSIJEK, OSIJEK, Croatia) USB RF Front-End of the DRM Receiver Under LabView API Environment  DRM (Digital Radio Mondiale) system uses software decoding what enables simpler RF front-end. DRM signal is a digital signal for radio broadcast on frequency bands below 30 MHz. The proposed USB RF front-end is designed to work with existing DRM software which uses soundcard as ADC between RF front-end and DRM decoding software. DAC of the decoded digital signal and audio reproduction is realized by PC integrated soundcard, while PWM (Pulse Width Modulation) used for frequency control of local oscillator uses DAC on external USB soundcard. In order to have a single software application, the existing DRM software is embedded in LabView environment which is developed for RF front-end control. 11. A. Trost, A. Žemva (FE, University of Ljubljana, Ljubljana, Slovenia) Verification Structures for Design of Video Processing Circuits  In the paper we present generic simulation test benches and test structures for the verification of the video processing circuits. The test benches accelerate simulation of the digital video frames in an ITU-R BT656 video format and a standard computer VGA format, which are most commonly used in our applications. The acceleration is achieved by selective stimuli in the area of the interest and selective collection of simulation results. We also present a custom FPGA based development system supporting both video formats. Several test structures were designed providing debug control and data for effective hardware verification. A video processing design case study is presented. With the presented verification methodology we are able to accelerate the design process of video processing circuits. The benefit of our approach is that it can be used with the standard programmable design tools and low cost platforms, since we do not require special software or hardware emulators. The approach can be used for the research or educational purpose. 12. D. Sekulić, M. Živanov (Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia) Computational Study on Soliton–like Pulses in the Nonlinear RLC Transmission Line  The nonlinear transmission line is a structure where short–duration pulses called electrical solitons can be created and propagated. In this paper, a model to study soliton–like pulses propagation along the nonlinear RLC transmission lines (NLTLs) periodically loaded with voltage dependent capacitances is presented. Based on Kirchhoff’s law taken in the continuum limit, exact soliton solutions of voltage equation are obtained by symbolic computation using an improved tanh–function (ITF) method. It is shown that the shape of soliton can be controlled well by adjusting the parameters of the line. These solutions may have important applications in communication systems where solitons are used to codify data. 13. A. Menicanin (Institute for Multidisciplinary Research, University of Belgrade, Belgrade, Serbia), L. Zivanov, M. Damnjanovic, A. Maric, N. Samardzic (Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia) Ink-jet Printed CPW Inductors in Flexible Technology  In this paper we present an ink-jet printed coplanar waveguide (CPW) inductors in flexible technology. We show design, fabrication, characterization and measurement technique of such devices. This is solution for ultra low-cost mass production. CPW inductors were developed as a technology for much simpler and faster fabrication on/in plastic foil. Structures are printed on Kapton substrate with polyamide silver nanoparticle ink. 14. J. Bajić, V. Milosavljević, V. Rajs, M. Slankamenac, M. Živanov (Faculty of Tehnical Science, Novi Sad, Serbia) Universal Wireless Communication Detector (UD-100) - Preventing of High-Tech Cheating Methods  In this paper the implementation of a device for wireless communication detection, which solve a problem of high-tech cheating, is presented. The system measures RF electro magnetic field strength for frequencies form 100MHz up to 2.4GHz and have wide range of adjustable sensitivity. Implemented device provides detection of cellular phone activities in all three main operating bands, and detection of other types of wireless communication such as radio communications, bluetooth, WiFi and so on. The device presents an improvement on a previous version of the detector MD-150. Measurement results are displayed on LED bar providing easy user readings and device operating. The system is battery powered, portable and can fit in any pocket. 15. M. Škiljo, Z. Blažević (Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, University of Spli, Split, Croatia) Investigation of Electrically Small Monofilar Spherical Helical Antenna Used for Mid-Range Wireless Power Transfer  This study is focused on electrically small monofilar spherical helical antenna for wireless power transfer (WPT) based on resonant coupling. WPT systems with different antenna geometry and loads at the receiving antenna are simulated and compared. The simulation results demonstrate some key WPT concepts including: the frequency splitting, critical coupling, impedance mismatch and the performance of electrically small antennas in WPT system design. By varying the spherical helical antenna geometry (diameter and number of turns) it is possible to achieve an efficient mid-range WPT at different frequencies. The antennas that best utilize the same physical volume achieve better power transfer efficiency over distance.