Microwave microphone using a general purpose 24 GHz FMCW radar

The usage of a commercial 24 GHz frequency-modulated continuous-wave (FMCW) radar sensor to retrieve sound signals is investigated in this article. Thanks to the great phase measurement capabilities of current radar sensors, low-frequency audio signals can be recovered by measuring the vibrations they induce in objects due to their pressure wave nature. To prove the concept, a sound emitted by a speaker is recorded by analysing the small-scale displacement of a reflective surface using a radar sensor originally devised for automotive and UAV applications at the 24 GHz ISM band

Synthesis considerations for acoustic wave filters and duplexers starting with shunt resonator

This project presents a synthesis procedure for acoustic wave ladder filters and duplexers taking also into consideration the case of networks whose first resonator is in shunt configuration. The feasibility of these networks in terms of the phase of the filter function is investigated and a lowpass synthesis view of the issues that might arise is presented providing different approaches for designers to achieve feasible networks.Aquest projecte presenta una metodologia de síntesi de filtres i duplexors d'ona acústica en topologia d'escala tenint també en compte el cas de les xarxes que comencen amb un ressonador en paral·lel. La viabilitat d'aquestes xarxes s'investiga en termes de la fase de la funció de filtrat i s'aporta una visió de síntesi pas baix de les limitacions que poden aparèixer, proveint alhora diferents solucions perquè els dissenyadors puguin obtenir xarxes viables

Star-shaped wheel for mechanical micro-Doppler modulation

This letter investigates the possibility of using deliberated geometries for rotating targets, which may improve the detectability and classification by means of its micro-Doppler signature. Beyond the signature provided by the rotation rate of the target, every particular geometry leads to specific and unique modulation waveforms that increase the information related to this target. Different star-shaped wheels with particular geometries have been designed demonstrating different reflection characteristics and modulation waveforms. The signature of these rotating star-shaped wheels has been measured in an anechoic chamber using a general-purpose 24 GHz frequency-modulated continuous wave (FMCW) radar platform and a detection algorithm based on the derivative of the cross-correlation is proposed to validate the proposed approach

Frequency-modulated continuous-wave radar in automotive applications

Premi UAB de la Fundació Autònoma Solidària (FAS) als millors Treballs de Fi de Grau sobre desenvolupament sostenible i justícia global. 2n Edició, curs 2017/2018Radar sensors on-board vehicles are a hot topic nowadays and are of key importance in improving automotive safety. In this project the principles of FMCW radar are presented and experiments are conducted in an RF anechoic chamber with the use of a trihedral corner reflector. Additionally, a low-cost dynamic target emulator for radar testing is designed and prototyped based on the hardware-in-the-loop concept.L'ús de sensors radar embarcats en vehicles és un tema potent actualment i de molta importància en la millora de la seguretat en l'automoció. En aquest projecte, es presenten els fonaments dels radar FMCW i es realitzen experiments en una cambra anecoica RF utilitzant un reflector trièdric. Alhora, s'implementa un emulador dinàmic de blancs radar de baix cost basat en el concepte del hardware-in-the-loop

Generalized multi-scale stacked sequential learning for multi-class classification

In many classification problems, neighbor data labels have inherent sequential relationships. Sequential learning algorithms take benefit of these relationships in order to improve generalization. In this paper, we revise the multi-scale sequential learning approach (MSSL) for applying it in the multi-class case (MMSSL). We introduce the error-correcting output codesframework in the MSSL classifiers and propose a formulation for calculating confidence maps from the margins of the base classifiers. In addition, we propose a MMSSL compression approach which reduces the number of features in the extended data set without a loss in performance. The proposed methods are tested on several databases, showing significant performance improvement compared to classical approaches

Mineralització i cartografia dels filons Ba-F-Pb-Zn de la Mina Juanita (Serra de Collserola, Barcelona) : interpretació del jaciment dins el Sistema Varisc Europeu

La mina Juanita està situada a la branca Sud - Est de les Carenes Costaneres Catalanes i està constituïda per un conjunt de filons de Ba-F-Pb-Zn encaixats dins d'un sòcol Paleozoic constituït per roques metasedimentaries d'edat Cambriana. Dins el Sistema Varisc europeu existeixen nombroses mines que presenten una morfologia i mineralogia semblants als de la mina Juanita. En aquest treball es presenta la cartografia de les galeries de la mina, descrivint les seves característiques dimensionals, morfològiques i mineralògiques; s'analitzen diferents mostres minerals en lamina prima i mostra de mà. Posteriorment, es realitza la paragènesis amb les dades obtingudes. Per similitud amb altres mineralitzacions, la gènesis interpretada en la mina en qüestió correspon a un jaciment hidrotermal de baixa temperatura molt semblant als que trobem en d'altres punts del Sistema Varisc Europeu. Aquests són conseqüència de la precipitació d'ions que circulaven amb fluids calents per fractures formades durant una època d'extensió Mesozoica. Els signes de deformació en els minerals de la mina demostren períodes de reactivació d'aquestes fractures, segurament com a conseqüència de l'orogènia Alpina o de l'extensió Neògena durant l'obertura del mar Mediterrani.Juanita mine is located in the South - East branch of the Catalan Costal Ranges and consists of a set of Ba-F-Pb-Zn veins scored inside Paleozoic rocks constituted by metasediments of Cambrian age. Within the European Variscan System there are numerous mines that have a similar morphology and mineralogy to Juanita mine. This paper presents the cartography of the galleries of the mine, describing its dimensional, morphological and mineralogical features; different hand and thin sections of mineral samples are analyzed; subsequently, the paragenesis is reconstructed with the data obtained. By similarity with other ores, the genesis of the Juanita mine must correspond to a low -temperature hydrothermal deposit similar to those found in other parts of the European Variscan System. These deposits are the result of precipitation of ions circulating within hot fluids through fractures formed during an epoch of Mesozoic extension. Signs of strain on the minerals of the mine show reactivation periods of these fractures, probably as a result of the Alpine orogeny or the Neogene extension during the opening of the Mediterranean Sea

Ovine herpesvirus type 2 (OvHV-2) infection rate in sheep herds of the Federal District, Brazil.

A febre catarral maligna (FCM) é uma doença causada pela infecção de bovinos pelo herpesvírus ovino tipo 2 (OvHV-2), responsável por perdas econômicas em diferentes regiões do Brasil. Neste trabalho descreve-se a detecção molecular por nested-PCR (nPCR) do OvHV-2 em amostras de secreção/esfoliação nasal e fração celular sanguínea (FCS) de ovinos provenientes de 8 propriedades do Distrito Federal. Das 188 amostras nasais analisadas, 88 (41,5%) foram positivas. Ovelhas prenhes não apresentaram diferenças na taxa de infecção em comparação com fêmeas paridas. Fêmeas recém-paridas apresentaram taxa de infecção pelo OvHV-2 maior que em animais que pariram há mais de 60 dias. Amostras de secreção/esfoliação nasal permitiram a detecção por nPCR de animais infectados com uma eficiência aproximadamente duas vezes maior que em amostras de fração celular sanguínea. No Brasil, informações epidemiológicas sobre a infecção pelo OvHV-2 nos rebanhos ovinos e fatores envolvidos no surgimento de surtos de FCM em bovinos são escassos. Este estudo pode servir de subsídio para elucidar as características da enfermidade e para novos estudos sobre a epidemiologia da doença no Distrito Federal e em outros Estados do Brasil.Malignant catarrhal fever (MCF) is a disease caused by bovine infection with ovine herpesvirus type 2 (OvHV-2) and responsible for economic losses in different Brazilian regions. This paper describes the molecular detection of OvHV-2 by nested-PCR (nPCR) in nasal secretion/exfoliation samples and blood cell fraction (BCF) of sheep from 8 properties in the Federal District. Among the 188 nasal samples, 88 (41.5%) were positive to OvHV-2. Pregnant ewe presented no differences at the infection rate in comparison with parous females. Newly calved sheep showed higher OvHV-2 infection rate than female over 60 days of calving. Nasal samples allowed the detection of infected animals by nPCR with efficiency about twice than that in the blood cell fraction samples. In Brazil, epidemiological information about OvHV-2 infection in sheep flocks and factors involved in emergence of FCM outbreaks in cattle are still scarce. This study may provide support for elucidating some characteristics of the disease and for further epidemiological studies in the Federal District and other Brazilian States

Synthesis considerations for acoustic wave filters and duplexers starting with shunt resonator

This project presents a synthesis procedure for acoustic wave ladder filters and duplexers taking also into consideration the case of networks whose first resonator is in shunt configuration. The feasibility of these networks in terms of the phase of the filter function is investigated and a lowpass synthesis view of the issues that might arise is presented providing different approaches for designers to achieve feasible networks.Aquest projecte presenta una metodologia de síntesi de filtres i duplexors d’ona acústica en topologia d’escala tenint també en compte el cas de les xarxes que comencen amb un ressonador en paral·lel. La viabilitat d’aquestes xarxes s’investiga en termes de la fase de la funció de filtrat i s’aporta una visió de síntesi pas baix de les limitacions que poden aparèixer, proveint alhora diferents solucions perquè els dissenyadors puguin obtenir xarxes viables

Synthesis of extracted pole filters with transmission zeros in both stopbands and nonresonant nodes of the same nature

Extracted pole filters alternating transmission zeros (TZs) above and below the passband are intrinsically related to the use of nonresonant nodes (NRNs) of different nature inductive and capacitive). This work demonstrates that it is possible to synthesize an extracted pole filter showing TZs on both sides of the passband but implementing all NRNs of the same reactive nature, overcoming the limitations imposed by some technologies. The proposed feature is achieved by special consideration of the input reflection phase of the generalized Chebyshev filter function, affecting input and output resonators and placing at most two zeros at the opposite band. A third-order all-capacitive prototype filter has been synthesized and fabricated to validate the proposed statement. The concept allows us to achieve all-capacitive or all-inductive filters

Phase Role in the Non-Uniformity of Main-Line Couplings in Asymmetric Extracted-Pole Inline Filters

The use of classical symmetrical polynomial definition to synthesize fully canonical inline filters with an asymmetrical distribution of the transmission zeros along the topology leads to the occurrence of uneven admittance inverter in the main-line. This form introduces some limitations to transform such topology into a ladder network. Despite circuital transformation can be used to accommodate both technology and topology, it is usual that extra reactive elements are necessary to implement phase shifts required to achieve the complete synthesis. This article introduces a novel method able to determine the required phase correction that has to be applied to the characteristic polynomials in order to equalize all the admittance inverters in the main path to the same value. It has been demonstrated that a suitable pair of phase values can be accurately estimated using a developed hyperbolic model which can be obtained from the transmission and reflection scattering parameters. To experimentally validate the proposed method, a Ladder-type filter with asymmetrical polynomial definition has been synthesized, fabricated, and measured, demonstrating the effectiveness of the developed solution