[ca] Aquest treball se centra en la implementaci ´o d'un analitzador d'imped 'ancia per a ser utilit- zat en la detecci ´o i an 'alisi de bacteris. El disseny se centra en la portabilitat i el cost, amb la finalitat de fer-lo apte per al treball de camp i poder fabricar m ´ultiples m 'oduls per a ser utilitzats tamb ´e en la universitat amb finalitats de recerca. Per a aix 'o, es realitza una etapa de recerca. En aquesta etapa es consideren, descriuen i discuteixen breument m ´ultiples topologies i m 'etodes de diferents treballs. Es discuteixen els avantatges i desavantatges de cada document i se selecciona un per a ser implementat. La topologia seleccionada es discuteix amb m ´es detall per a mostrar les seves limitacions i es fa un treball te 'oric per a extreure una aproximaci ´o matem 'atica del comportament del circuit. Per a complementar l'an 'alisi te 'orica s'utilitzen simulacions per ordinador amb SPICE per a il·lustrar millor el comportament del circuit, aix´ı com per a verificar el treball te 'oric i determinar l'efecte de les parasitancies i les no idealitats. Posteriorment, el circuit es dissenya en una placa de circuit impr 'es utilitzant Kicad i es fabrica centrant-se en la simplicitat per a reduir costos. S'utilitza una Red Pitaya com ADC i DAC per a unir els dominis digital i anal 'ogic i tamb ´e com a microcontrolador. La placa s'utilitza per a generar els senyals d'excitaci ´o i processar les formes d'ona generades per a extreure la informaci ´o necess 'aria. La placa es programa en C i es crea una aplicaci ´o JavaScript senzilla i lleugera que serveix de front-end, utilitzant HTML i CSS per a crear una interf´ıcie gr 'afica que permeti observar millor els resultats. Finalment, es prova el sistema per a comprovar la seva funcionalitat, es discuteixen els resultats i es comenten algunes propostes de millora. Finalment, aquest treball tamb ´e descriu el cost econ 'omic i ecol 'ogic del projecte, aix´ı com el cost en m 'a d'obra.

[en] This work focuses on the implementation of an impedance analyzer to be used on the detection and analysis of bacteria. The focus of the design is on portability and cost in order to make it suitable for field work and to be able to manufacture multiple modules to be also used on the university for research purposes. For that purpose, a research stage is performed. In this stage multiple topologies and methods from different papers are considered, described and briefly discussed. The advantages and disadvantages of each paper are discussed and one is selected to be implemented. The selected topology is discussed in more detail in order to show its limitations and theoretical work is done in order to extract a mathematical approximation of the behavior of the circuit. In order to further complement the theoretical analysis computer simulations with SPICE are used to better illustrate the behavior of the circuit, as well as to verify the theoretical work and to determine the effect of parasitics and non idealities. Afterwards, the circuit is designed into a PCB using Kicad and manufactured with a focus on simplicity so as to reduce costs. A Red Pitaya is used as an ADC and DAC to bridge the digital and analog domains. The board is used to generate the excitation signals and to process the generated waveforms to extract the necessary information. The board is programmed on C and a simple and lightweight JavaScript application is created to serve as front end, using HTML and CSS to create a graphical interface to better observe the results. Finally, the system is tested to verify its functionality, the results are discussed and some proposals for improvements are commented. Finally, this work also describes the economic and ecologic cost of the project, as well as the cost in manpower.