Integration d'un amplificateur RF reconfigurable en frequence

Wireless telephony uses different frequency bands (900 MHz, 1800 MHz, 1900 MHz, 2200 MHz...), hence most mobile phones on the market nowadays offer to cover these bands with tri-band or quad-band mobile phones. This imposes a multiplication of circuits for the reception and emission of radio frequencies.;A possible solution to reduce the space occupied by RF amplifiers within the chain of emission-reception is the use of reconfigurable RF amplifiers (so called intelligent amplifiers). Components from RF-MEMS technology makes this reconfigurability possible. The development of technologies such as the surface micro-machining makes it possible to manufacture micromechanical systems that allow accomplishing switching functions.;The use of such components in the microwave field allows fabricating MEMS impedance tuners, which allow matching impedance to the RF amplifier depending of the frequency of operation. In this thesis we study different types of microwave impedances tuners, specially coaxial impedance tuners and MEMS impedance tuners and we analyse their use to build reconfigurable RF amplifiers.;Key words : Variable impedance matching network, RF-MEMS, Intelligent RF, DMTL...