Patent ID: 7103114

Claim:
A transmitter of radio signals, referred to as output modulated signals (SMS), which are modulated at least in amplitude according to a discrete plurality of predetermined separate amplitude levels (A 1 , A 2 , A 3 ), on the basis of digital control signals ( 1 ) comprising: modulation means ( 3 ) adapted to convert the digital control signals ( 1 ) into modulated signals, referred to as input modulated signals (SME); solid-state power amplification means ( 5 ) including at least one power transistor, at least one said at least one power transistor being an output power transistor ( 6 ) delivering output modulated signals (SMS); bias means ( 7 ) including at least one voltage source, and adapted to bias each power transistor of the amplification means ( 5 ), wherein the bias means ( 7 ) are adapted to be able to deliver, for at least one terminal to be biased in each output power transistor ( 6 ) of the amplification means ( 5 ), a predetermined discrete plurality of separate bias-voltage levels (VD 1 , VD 2 , VD 3 ), each bias-voltage level being associated with and adapted to at least one of said amplitude levels (A 1 , A 2 , A 3 ) of the output modulated signals (SMS); analysis means ( 11 ), adapted to generate in real time, on the basis of the instantaneous value of the digital control signals ( 1 ), a signal, referred to as a selection signal (SS), whose instantaneous value is representative of the instantaneous amplitude level needing to be taken by the output modulated signals (SMS) to be transmitted corresponding to this instantaneous value of the digital control signals ( 1 ), the instantaneous value of the selection signal (SS) varying with the digital control signals ( 1 ) according to a discrete plurality of values corresponding to the various amplitude levels (A 1 , A 2 , A 3 ) of the output modulated signals (SMS); and switch means ( 10 ) receiving the selection signal (SS), and adapted to select and apply at each instant, to said terminal to be biased, a bias voltage that is delivered by the bias means ( 7 ) and whose value is equal to one of the bias-voltage levels, the selected bias-voltage level being associated with and adapted to the amplitude level represented by the instantaneous value of the selection signal (SS).