A multiple power mode amplifier provides a low and a high power mode without using switches. This amplifier may be used in radio frequency (RF) applications such as mobile telephones, pagers, portable digital assistants, and wireless e-mail devices. In the low power mode, the power consumption of the amplifier is reduced, which will increase operation time, especially important for battery-operated devices. In one implementation, the amplifier includes a number of impedance matching network units (130, 140, 150, and 160), impedance transformer (170), and a power stage (120). An implementation provides further power consumption savings by modulating a bias of an amplifier stage.

 
Web www.patentalert.com

< Closed loop power control of non-constant envelope waveforms using sample/hold

> Compact radio frequency transmitting and receiving antenna and control device employing same

~ 00440