An important evolution in wireless communication systems involves the introduction of more intelligence and reconfigurability in the transceiver in order to obtain more efficient spectral resource management and better transmission quality with low energy consumption. The frequency band of interest is located between 600 MHz and 6 GHz. In this band, the mobile transmitters must be able to operate at different frequency bands and modes, according to existing standards specifications. Different approaches have been developed, but they all show limits. In a first step, we will study the constraints related to the concept of multi-standard or multi-radio transmitter. Then, we will analyze different approaches to achieve such low consumption reconfigurable architectures and detail advantages and limits. Description: - High efficiency amplifiers : Martine Villegas - 40 mn o Review of high efficiency classes o Design principles in order to achieve multiband amplifier, reconfigurable amplifier or wide band amplifier, consistent with the global transmitter architecture