Abstract : The study, which is described in this dissertation, is dedicated to passive components in order to be integrated into high temperature power electronic converters. Capacitors and magnetic materials are selected and characterized up to 250°C. Electrical and electromagnetic characteristics are measured. Some components show a significant temperature deviation, but also a non-linear behavior with a hysteresis phenomenon. Based on these characteristics, a high temperature EMI filter for a 2kW voltage inverter is designed. The design procedure and some practical considerations are discussed. Then, the experimental results from the prototype at 200°C under full load conditions are given. The variation of the conducted emissions, from 150kHz and 30MHz, with the temperature is low (about +6dBµA between 25°C and 200°C into a DO-160F setup). The feasibility of a working EMI filter for high temperature power electronics is demonstrated. To meet the high frequency EMI requirements, with wide-band gap semi-conductors devices which are faster than Si IGBT, a solution based on integrated common mode capacitors into the power module is proposed. With this solution, operation at high temperature is also doable. Experimental results show a reduction of the conducted emissions thanks to these integrated capacitors. We consider this solution as an alternative against an increased complexity of the EMI input filter. It follows the present trends toward the integration of functions into a power module, close to the power switches. Moreover, packaging issues are highlighted and remains as a major limitation for high temperature power electronics.