The fields of health care and environment control have an increasing demand for sensors able to detect low concentrations of specific molecules in gaseous or liquid samples. The recent introduction of microfabricated devices in these fields gave rise to sensors with attractive properties. A cutting edge technology is based on guided acoustic waves, which are perturbed by events occurring at the nanometer scale. A first part of the thesis investigates the Love mode waveguide, a versatile structure in which a thin film is guiding the acoustic wave generated in a piezoelectric substrate. A systematic analysis of its sensitivity was obtained using a transmission line model generalized to discriminate the rigid or viscous nature of the probed layers. We developed a novel integrated combination of the Love mode device with a Surface Plasmon Resonance optical sensor to quantify the thickness and the composition of soft layers. The electromagnetic interferences in the recorded signal were modeled to determine the phase velocity in the sensing area and to provide new mechanisms for an enhanced sensitivity. The experimental aspects of this work deal with the fabrication, the important issue of the packaging and the sensitivity calibration of the Love mode biosensor. A second part of the thesis investigates nanocrystalline diamond under the form of a thin film membrane suspended to a rigid silicon frame. The high mechanical and chemical resistance of nanocrystalline diamond, close to single-crystal diamond, open ways to membrane based acoustic sensors such as Flexural Plate Wave and thin Film Bulk Acoustic Resonators (FBAR). A novel dynamic characterization of the thin film is reported and the properties of composite FBAR devices including a diamond thin film membrane and a piezoelectric aluminum nitride layer are assessed using the perturbation theory. This study is applied to evaluate the high sensing potential of the first prototype of an actual diamond-based composite FBAR.

As the interest in intentional electromagnetic interference (IEMI) increases, so does the need of a suitable antenna which endures those demanding conditions. The ultrawideband (UWB) technology provides an elegant way of generating high-voltage UWB pulses which can be used for IEMI. One UWB antenna, invented solely for the purpose of radiating pulses, is the impulse radiating antenna (IRA). In the course of this master thesis work, a suitable geometry of the IRA is suggested, and modelled, for the high-voltage application of 90 kV.

Electromagnetic interference (EMI) is one of the most common problems encountered in microwave applications. Interaction of electromagnetic (EM) waves from different sources may result in device malfunction due to misinterpretation of the transferred data or information loss. On the other hand, development of materials with reduced radar detectability is desired in defense applications. Considering the limitations in weight and thickness, development of lightweight structural materials with enhanced electromagnetic absorption potential is needed. In this study, development and characterization of glass fiber-reinforced polymer (GFRP) composite materials to be used in EM wave absorbing or EMI shielding applications was aimed. Incorporation of electromagnetic wave absorption characteristic has been achieved by the application of conductive thin film on fiber glass woven fabric reinforcement layers. Characterization of EM wave absorption potential was conducted using &ldquo / free-space method&rdquo / in 18 &ndash / 27 GHz frequency range. Single and multilayered combinations of surface-modified fiber glass woven fabrics were characterized in terms of their EM wave interaction properties and design principles for efficient broadband EM wave absorbing multilayered GFRP composite material have been presented. A computer aided computation method has also developed in order to predict EM wave transmission, reflection, and hence absorption characteristics of multilayered structures from single layer properties. Estimated results were verified compared to free-space measurement results. In the current study, up to 85% electromagnetic wave absorption has been obtained within 18-27 GHz frequency range (K band). Enhancement of EM wave absorption potential of multilayer structure has also been demonstrated by computer aided computation.

In the recent years, there has been a trend to run metallic pipelines carrying petroleum products and high voltage AC power lines parallel to each other in a relatively narrow strip of land. The case of electromagnetic interference between high voltage transmission lines and metallic pipelines has been a topic of major concern since the early 60’s. The main reasons for that are: • The ever increasing cost of right-of-ways, suitable for power lines and pipelines, along with recent environmental regulations, aiming to protect nature and wildlife, has forced various utilities to share common corridors for both high voltage power lines and pipelines. Therefore, situations where a pipeline is laid at close distance from a transmission line for several kilometers have become very frequent. • The rapid increase in energy consumption, which has led to the adoption of higher load and short circuit current levels, thus making the problem more acute. Due to this sharing of the right-of-way, overhead AC power line field may induce voltages on the metallic pipelines running in close vicinity leading to serious adverse effects. This electromagnetic interference is present both during normal operating conditions as well as during faults. The coupling of the field with the pipeline takes place either through the capacitive path or through the inductive or conductive paths. In the present work, the induced voltages due to capacitive and inductive coupling on metallic pipelines running in close vicinity of high voltage power transmission lines have been computed.The conductor surface field gradients calculated for the various phaseconfigurations have been presented in the thesis. Also the electric fields under transmission lines, for both single circuit and double circuit (various phase arrangements) have been analysed. Based on the above results, an optimum configuration giving the lowest field under the power line as well as the lowest conductor surface gradient has been arrived at and for this configuration induced voltage on the pipeline has been computed using the Charge Simulation Method (CSM). For comparison, induced voltages on the pipeline have been computed for the various other phase configurations also. A very interesting result is that the induced voltage on the pipeline becomes almost negligible at a critical lateral distance from the center of the powerline and beyond which the induced voltage again increases.This critical distance depends on the conductor configuration. Hence it is suggested that the pipeline be located close to the critical distance so that the induced voltage would be close to zero. For calculating the induced voltage due to the inductive coupling, electromotive force (EMF),induced along the pipeline due to the magnetic field created by the transmission line has been calculated. The potential difference between the pipeline and the earth, due to the above induced EMFs, is then calculated. As the zones of influence are generally formed by parallelism, approaches, crossings as well as removals, the computation involves subdividing the zone into several sections corresponding to these zones. The calculation of voltages is carried out at both the ends of the sections. Each section is represented by an equivalent π electrical network, which is influenced by the induced EMF. The induced EMF is calculated during faulted conditions as well as during steady state conditions. Inductive coupling calculations have been carried out for the following cases: •Perfect parallelism between powerline and pipeline. •zone of influences formed by parallelism, approaches, crossings and removals. It has been observed that when the pipeline is approaching the HV transmission line at an angle, then running parallel for certain distance and finally deviating away, the induced voltage is maximum at the point of approach or removal of the pipeline from the transmission line corridor.The induced voltage is almost negligible near to the midpoint of the zone of influence. The profile of the induced voltage also depend on whether the pipeline is grounded or left open circuited at the extremities of the zone of influence. Effect of earth resistivity and anti-corrosive coatings on induced voltage has also been studied. For mitigating the induced voltage on the pipeline,numerous low resistive earthings have been suggested. Results show that significant reduction in induced voltage can be achieved as the number of earth points is increased.

The dissertation documents research work carried out on Pulse Width Modulation (PWM) strategies for hard switched Voltage Source Inverters (VSI) for variable speed electric drives. This research is aimed at Hybrid Electric Vehicles (HEV). PWM is at the heart of all variable speed electric drives; they have a huge influence on the overall performance of the system and may also help eventually give us an extra degree of freedom in the possibility to rethink the inverter design including the re-dimensioning of the inverter components.HEVs tend to cost more than conventional internal combustion engine (ICE) vehicles as they have to incorporate two traction systems, which is the major discouraging factor for consumers and in turn for manufacturers. The two traction system increases the maintenance cost of the car as well. In addition the electric drives not only cost extra money but space too, which is already scarce with an ICE under the hood. An all-electric car is not yet a viable idea as the batteries have very low energy density compared with petrol or diesel and take considerable time to charge. One solution could be to use bigger battery packs but these add substantially to the price and weight of the vehicle and are not economically viable. To avoid raising the cost of such vehicles to unreasonably high amounts, autonomy has to be compromised. However hybrid vehicles are an important step forward in the transition toward all-electric cars while research on better batteries evolves. The objective of this research is to make electric drives suitable for HEVs i.e. lighter, more compact and more efficient -- requiring less maintenance and eventually at lower cost so that the advantages, such as low emissions and better fuel efficiency, would out-weigh a little extra cost for these cars. The electrical energy source in a vehicle is a battery, a DC Voltage source, and the traction motor is generally an AC motor owing to the various advantages it offers over a DC motor. Hence the need for a VSI, which is used to transform the DC voltage into AC voltage of desired amplitude and frequency. Pulse width modulation techniques are used to control VSI to ensure that the required/calculated voltage is fed to the machine, to produce the desired torque/speed. PWM techniques are essentially open loop systems where no feedback is used and the instantaneous values differ from the required voltage, however the same average values are obtained. Pulse width modulated techniques produce a low frequency signal (desired average value of the switched voltage) also called the fundamental component, along with unwanted high frequency harmonics linked to the carrier signal frequency or the PWM period. In modern cars we see more and more mechanical loads driven by electricity through digital processors. It is very important to eliminate the risk of electromagnetic interference between these systems to avoid failure or malfunction. Hence these unwanted harmonics have to be filtered so that they do not affect the electronic control unit or other susceptible components placed in the vicinity. Randomised modulation techniques (RPWM) are used to dither these harmonics at the switching frequency and its multiple. In this thesis a random modulator based on space vector modulation is presented which has additional advantages of SVM. Another EMI problem linked to PWM techniques is that they produce common mode voltages in the load. For electric machines, common mode voltage produces shaft voltage which in turn provokes dielectric stress on the motor bearings, its lubricant and hence the possibility of generating bearing currents in the machine that can be fatal for the machine. To reduce the common mode voltage a space vector modulation strategy is developed based on intelligent placement of zero vectors. (...)

Interference and jamming severely disrupt our ability to communicate by decreasing the effective signal-to-noise ratio and by making parameter estimation difficult at the receiver. The objective of this research work is to design robust wireless systems and algorithms to suppress the adverse effects of non-intentional co-channel interference (CCI) or intentional jamming. In particular, we develop chip-combining schemes with timing, channel, and noise-power estimation techniques, all of which mitigate CCI or jamming. We also exploit the spatial diversity and iterative receiver techniques for this purpose. Most of the existing timing estimation algorithms are robust against either large frequency offsets or CCI, but not against both at the same time. Hence, we develop a new frame boundary estimation method that is robust in the presence of severe co-channel interference and large carrier-frequency offsets. To solve the high peak-to-average-power ratio problem of a multicarrier code division multiple access (MC-CDMA) system and enhance its robustness against fading and jamming, we propose a constant-envelope MC-CDMA system employing cyclic delay diversity (CDD) as transmit diversity. We analyze the diversity order, coding gain, and bit-error rate upper bound. We also propose a blind, accurate, and computationally efficient signal-to-noise ratio estimator for the proposed system. We propose a configurable robust anti-jam receiver that estimates the frequency- or time-domain jammer state information (JSI) and uses it for chip combining in the corresponding domain. A soft-JSI-based chip-combining technique is proposed that outperforms conventional hard-JSI-based chip combining. We also derive a chip combiner that provides sufficient statistics to the decoder. Channel estimation is necessary for coherent signal detection and JSI estimation. Conversely, knowledge of the jamming signal power and JSI of different subcarriers can improve the accuracy of the channel estimates. Hence, we propose joint iterative estimation of the multiple-input multiple-output (MIMO) channel coefficients, jamming power, and JSI for a coded MC-CDMA MIMO system operating under jamming and a time-varying frequency-selective fading channel. Finally, we reduce the computational complexity of the JSI-based anti-jam receivers by introducing an expectation-maximization-based joint channel and noise-covariance estimator that does not need either the subcarrier JSI or the individual powers of the AWGN and jamming signal.

Ο σκοπός αυτής της εργασίας είναι να προωθηθεί ένας οδηγός σχετικά με τις κατασκευαστικές προδιαγραφές και την απόδοση των ηλεκτρομαγνητικών ανηχοικών θαλάμων και των εσωτερικών εγκαταστάσεων δοκιμής. Εντούτοις, απαιτείται κάποια γνώση ηλεκτρομαγνητικών μετρήσεων, για να εξασφαλιστεί ότι όλοι οι εφαρμόσιμοι κατασκευαστικοί παράγοντες, έχουν εφαρμοστεί στις καταστάσεις που θα ζητηθούν. Η μέτρηση των ηλεκτρομαγνητικών κυμάτων περιλαμβάνει μεγάλο αριθμό ηλεκτρονικών συσκευών. Αυτές οι συσκευές μπορούν να ταξινομηθούν σε άμεσους ή σε έμμεσους εκπομπούς. Η μέτρηση των άμεσων εκπομπών (όπως οι κεραίες) ή η εκπομπή της ηλεκτρομαγνητικής ενέργειας, όπως στη διατομή του ραντάρ, απαιτεί εξειδικευμένες εγκαταστάσεις. Ο καθορισμός του επιπέδου ακτινοβολίας από τους έμμεσους εκπομπούς όπως οι ψηφιακές συσκευές ή ο καθορισμός του επιπέδου «ευαισθησίας» που έχει μια ηλεκτρονική συσκευή, όσον αφορά ένα εισερχόμενο ηλεκτρομαγνητικό κύμα περιλαμβάνει επίσης τη μέτρηση των ηλεκτρομαγνητικών κυμάτων στις εγκαταστάσεις που σχεδιάζονται συγκεκριμένα για τη μέτρηση που πραγματοποιείται. Ηλεκτρομαγνητικό κύμα είναι το αποτέλεσμα από την επιτάχυνση των ηλεκτρικών φορτίων. Το ηλεκτρικό πεδίο λόγω μιας ανεπιθύμητης φόρτισης (σε κάποια δοκιμή ή στην ομοιόμορφη κίνηση σε μια ευθεία γραμμή) κατευθύνεται ακτινωτά και μειώνεται ως το τετράγωνο της απόστασης από τη φόρτιση. Εντούτοις, η επιτάχυνση της φόρτισης προκαλεί αύξηση του ηλεκτρικού πεδίου, και μειώνεται γραμμικά με την απόσταση. Στην πράξη, σχεδόν πάντα υπάρχει ενδιαφέρον για τα μακροσκοπικά αποτελέσματα. Στην μακροσκοπική κλίμακα, η αλληλεξάρτηση μεταξύ των ηλεκτρικών και μαγνητικών πεδίων περιγράφεται από μαθηματική άποψη από τις εξισώσεις Maxwell [ 2 ..3 ]. Τα μαθηματικά των ηλεκτρομαγνητικών πεδίων και των σχετικών μέσων χρησιμοποιούν την διανυσματική ανάλυση. Η ανάλυση μπορεί να αναμιχθεί πολύ, σε πολλά προβλήματα, ειδικά εκείνα που περιλαμβάνουν τη διάδοση στα μη ισοτροπικά , μη-αμοιβαία, μη γραμμικά, ή ανομοιογενή μέσα. Αν και ορισμένα προβλήματα στις ηλεκτρομαγνητικές μετρήσεις μπορούν να απαιτήσουν την εφαρμογή πιο λεπτομερών μαθηματικών. Στους ανηχοικούς θαλάμους πραγματοποιούνται δύο ειδών δοκιμές, η δοκιμή ηλεκτρομαγνητικής παρεμβολής (EMI) και η δοκιμή ηλεκτρομαγνητικής συμβατότητας (EMC). Ηλεκτρομαγνητική παρεμβολή (EMI) είναι κάθε σήμα ή εκπομπή που ακτινοβολείται στον χώρο ή άγεται σε καλώδια τροφοδοσίας ή σημάτων και θέτει σε κίνδυνο τη λειτουργία συστημάτων ασύρματης πλοήγησης ή άλλες υπηρεσίες ασφαλείας ή υποβαθμίζει, παρεμποδίζει ή διακόπτει επανειλημμένα μια αδειοδοτημένη υπηρεσία ασύρματων επικοινωνιών. Στις υπηρεσίες ασυρμάτων επικοινωνιών περιλαμβάνονται, ενδεικτικά, οι εμπορικές εκπομπές AM/FM, η τηλεόραση, η κινητή τηλεφωνία, τα ραντάρ, ο έλεγχος εναέριας κυκλοφορίας, η τηλεειδοποίηση και οι Υπηρεσίες Προσωπικής Επικοινωνίας (Personal Communication Services ή PCS). Αυτές οι αδειοδοτημένες και οι μη αδειδοτημένες υπηρεσίες ασυρμάτων επικοινωνιών, όπως το WLAN ή το Bluetooth, μαζί με ακούσιους πομπούς όπως ψηφιακές συσκευές, συμπεριλαμβανομένων συστημάτων υπολογιστών, συμβάλλουν στο ηλεκτρομαγνητικό περιβάλλον. Η ηλεκτρομαγνητική συμβατότητα (ΗΜΣ) είναι η δυνατότητα στοιχείων του ηλεκτρονικού εξοπλισμού να λειτουργούν ομαλά μαζί, μέσα σε ηλεκτρονικό περιβάλλον. Παρόλο που το συγκεκριμένο σύστημα υπολογιστή έχει σχεδιαστεί και έχει προσδιοριστεί ως συμβατό με τα όρια που καθορίζονται από το φορέα κανονισμών για ηλεκτρομαγνητικές παρεμβολές, δεν παρέχεται κανενός είδους εγγύηση ότι δεν θα υπάρξει παρεμβολή σε μία συγκεκριμένη εγκατάσταση. Τα προϊόντα της EMC Corporation είναι σχεδιασμένα, ελεγμένα και κατηγοριοποιημένα σύμφωνα με το συγκεκριμένο ηλεκτρομαγνητικό περιβάλλον χρήσης τους. Αυτές οι κατηγορίες ηλεκτρομαγνητικού περιβάλλοντος αναφέρονται γενικά στους ακόλουθους εναρμονισμένους ορισμούς: • Τα προϊόντα κατηγορίας B προορίζονται για χρήση σε οικιακά περιβάλλοντα, αλλά μπορούν επίσης να χρησιμοποιηθούν σε μη οικιακά περιβάλλοντα. Σημείωση: Οικιακό περιβάλλον είναι ένα περιβάλλον όπου η χρήση πομπών ραδιοσυχνοτήτων και τηλεοπτικών δεκτών μπορεί να είναι αναμενόμενη σε απόσταση 10 m από το σημείο που χρησιμοποιείται το προϊόν. • Τα προϊόντα κατηγορίας A προορίζονται για χρήση σε μη οικιακά περιβάλλοντα. Τα προϊόντα κατηγορίας A μπορούν επίσης να χρησιμοποιηθούν σε οικιακά περιβάλλοντα, αλλά ενδέχεται να προκαλέσουν παρεμβολές και να απαιτηθεί η λήψη διορθωτικών μέτρων από το χρήστη. Εάν αυτός ο εξοπλισμός προκαλέσει παρεμβολή σε υπηρεσίες ραδιοεπικοινωνιών, η οποία παρεμβολή διαπιστώνεται ενεργοποιώντας και απενεργοποιώντας τον εξοπλισμό, επιχειρήστε να διορθώσετε την παρεμβολή ενεργώντας ως εξής: • Επαναπροσανατολισμός της κεραίας λήψης. • Αλλαγή θέσης του υπολογιστή σε σχέση με το δέκτη. • Μετακίνηση του υπολογιστή μακριά από το δέκτη. • Σύνδεση του υπολογιστή σε διαφορετική πρίζα έτσι ώστε ο υπολογιστής και ο δέκτης να βρίσκονται σε διαφορετικά κυκλώματα. Εάν είναι απαραίτητο, επικοινωνήστε με έναν τεχνικό υποστήριξης της EMC Corporation ή κάποιο εξειδικευμένο τεχνικό ραδιοφώνων/τηλεοράσεων ή ειδικό ΗΜΣ για περαιτέρω υποδείξεις. Ο εξοπλισμός τεχνολογίας πληροφοριών (ITE) που περιλαμβάνει περιφερειακά όπως κάρτες επέκτασης, εκτυπωτές, συσκευές εισόδου/εξόδου (I/O), οθόνες κ.λπ., και οι οποίες είναι ενσωματωμένες μέσα στο σύστημα ή συνδεδεμένες σε αυτόν, πρέπει να συμμορφώνεται με την κατηγορία ηλεκτρομαγνητικού περιβάλλοντος του υπολογιστή. / The purpose of this paper is to provide a guide on the design and performance specification of electromagnetic anechoic chambers or indoor test facilities. However, some knowledge of electromagnetic measurements is required to ensure that all applicable design factors have been applied in any given design situation. The measurement of electromagnetic waves involves a large number of electronic devices. These devices can be categorized as intentional or unintentional radiators. Measurement of intentional radiators (such as antennas) or the scattering facilities. Determining the level of radiation from unintentional radiators such as digital devices or determining the level of immunity an electronic device has with respect to an impinging electromagnetic wave also involves the measurement of electromagnetic waves in testing facilities designed specifically for the measurement to be performed. Electromagnetic waves result from the acceleration of electric charges. The electric field due to an unaccelerated charge (one at rest or in uniform motion in a straight line) is radially directed and decreases as the square of the distance from the charge. However, the acceleration of the charge gives rise to a tangential component of the electric field, and this decreases linearly with distance. This time-varying electric field has associated with it a time varying magnetic field, together, they comprise an electromagnetic field. An electromagnetic field that decreases linearly with distance represents an outward radiation. In practice, one is almost always concerned with macroscopic effects resulting from acceleration of gross numbers of charges. On the macroscopic scale, the interrelationship between electric and magnetic fields is described mathematically by Maxwell’s equations. An additional set of equations called constitutive relationships specifies the characteristics of the medium in which the field exists. The mathematics of electromagnetic fields and the associated media makes use of vector and tensor analysis. The analysis can become very involved in many problems, especially those involving propagation in nonisotropic, nonreciprocal, nonlinear, or nonhomogeneous media. Although certain problems in electromagnetic measurements can require application of more detailed mathematics. In anechoic chambers, take place two types of tests, the electromagnetic interference test (EMI) and the electromagnetic compatibility testing (EMC). Electromagnetic interference (EMI) is any signal or emission radiated in space or is induced in cables or signals and threatening the operation of wireless navigation services or other security or degrade, obstruct or repeatedly interrupts a licensed radio communications service. In wireless communications services including, without limitation, commercial broadcasting AM / FM, TV, mobile telephony, radar, air traffic control, paging and personal communications services (Personal Communication Services or PCS). These licensed and non licensed wireless communications such as WLAN or Bluetooth, along with unintentional transmitters such as digital devices, including computer systems, contribute to the electromagnetic environment. The electromagnetic compatibility (EMC) is the potential components of electronic equipment to operate seamlessly together in an electronic environment. While this computer system has been designed and determined to be compatible with the limits set by the service regulations for electromagnetic interference, there is no guarantee that interference will not occur in a particular installation. Its products are EMC Corporation is designed, tested and categorized according to the specific electromagnetic environment of use. These types of electromagnetic environment generally refers to the following harmonized definitions: • Products category B for use in domestic environments, but can also be used in non-domestic environments. Note: the domestic environment is an environment where the use of RF transmitters and television receivers may be expected within 10 m from where the product is used. • Class A products are intended for use in non-domestic environments. Class A products can also be used in domestic environments, but it may cause interference and require remedial action by the user. If this equipment cause interference to radio services, which insert shows activating and disabling the equipment, try to correct the interference by acting as follows: • Reorient the receiving antenna. • Relocating the computer to the receiver. • Move the computer away from the receiver. • Connect the computer into a different outlet so that computer and receiver are on different circuits. If necessary, contact technical support EMC Corporation or any qualified radio / TV technician or special EMC for further instructions. Information technology equipment (ITE), including peripherals such as expansion cards, printers, input / output (I / O), monitors, etc., which are embedded in the system or connected to it, must comply with Category electromagnetic environment of the computer.

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2017-12-20T12:53:31Z No. of bitstreams: 1 mathausferreiradasilva.pdf: 22275886 bytes, checksum: 2238ed4aba60d835720fda3dd8bc6e46 (MD5) / Rejected by Adriana Oliveira (adriana.oliveira@ufjf.edu.br), reason: Corrigir nome membro da banca e colocar acento no Júnior - do co-orientador Membro da banca: Moraes, Carlos Henrique Valério de on 2017-12-21T11:18:47Z (GMT) / Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2017-12-21T12:02:50Z No. of bitstreams: 1 mathausferreiradasilva.pdf: 22275886 bytes, checksum: 2238ed4aba60d835720fda3dd8bc6e46 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-12-22T12:01:34Z (GMT) No. of bitstreams: 1 mathausferreiradasilva.pdf: 22275886 bytes, checksum: 2238ed4aba60d835720fda3dd8bc6e46 (MD5) / Made available in DSpace on 2017-12-22T12:01:34Z (GMT). No. of bitstreams: 1 mathausferreiradasilva.pdf: 22275886 bytes, checksum: 2238ed4aba60d835720fda3dd8bc6e46 (MD5) Previous issue date: 2017-08-28 / Este trabalho tem por objetivo aplicar a técnica do Filtro de Kalman Estendido com ruído colorido a uma aeronave do tipo quadrotor para atenuar a interferência eletro-magnética proveniente de linhas de transmissão de energia de modo a aumentar a confiabilidade e segurança de voos em suas proximidades. Com o intuito de executar missões de monitoramento autônomo, a técnica desenvolvida visa estimar o valor da interferência eletromagnética produzida por linhas de transmissão de energia em alta tensão para que seja possível aplicar a correção necessária. Essa estimação e´ feita a partir do modelo matemático do campo eletromagnético da linha, que leva em consideração a posição, corrente da linha, sistema físico de transmissão, entre outros. Para a avaliação dos resultados, utilizou-se os índices de performance não intrusivos que levam em consideração a integral absoluta do erro (IAE) e a integral do erro quadrático (ISE). Os resultados foram considerados eficientes e aplicáveis com base nos índices de desempenho, permitindo que o quadrotor executasse todas as missões como planejadas, sendo possível ainda a diminuição da distância entre o veículo e a linha de transmissão que, por consequência, permite uma análise mais detalhada e aumenta a qualidade do monitoramento e identificação de avarias ao longo do percurso. / This work aims to apply the Extended Kalman Filter technique with colored noise to a quadrotor-type aircraft to attenuate electromagnetic interference from power trans-mission lines in order to increase the reliability and safety of nearby flights. To perform autonomous monitoring missions, the developed technique aims to estimate the value of the electromagnetic interference produced by high voltage power transmission lines, which makes possible to apply the necessary correction. This estimation is made from the mathematical model of the power line electromagnetic field, which takes into ac-count the position, line current, physical transmission system, among others. In order to evaluate the results, it was used non-intrusive performance indexes that take into account the integrated absolute error (IAE) and the integrated square error (ISE). The results were considered efficient and applicable based on performance indices, allowing the operator to perform all the missions as planned, and the distance between the vehicle and the transmission line can be reduced which, consequently, result in a more detailed analysis and increases the monitoring quality and the faults identification along the route.

No description available.

The master thesis deals with the design of a low noise preamplifier operating in the frequency range from 30 MHz to 1 GHz, usable for measuring and testing of electromagnetic interference in the electromagnetic compatibility test rooms. The introductory, theoretical, part is focused on the analysis and description of the necessary properties of the low noise preamplifier required for the subsequent design. The practical part deals with the selection of suitable components, simulation, design and subsequent realization of low noise preamplifier. At the end of the thesis the design and the final verification measurements are described and discussed.