RECONFIGURABLE POWER AMPLIFIER FOR IMPROVED LOW-POWER EFFICIENCY

摘要

A radio frequency (RF) power amplifier (PA) is reconfigured to operate in a low power mode from a high power mode. The RF PA has a first RF amplifier is connected to the first and second inputs of a first transformation network. The RF PA has a second a second RF amplifier connected to a second transformation network. During high power mode, both RF amplifiers drive a load coupled to the transformation networks. In low power mode the first RF amplifier is disabled and the first and second inputs of the first transformation are coupled together so as to change the load impedance seen by the second RF amplifier. The second RF amplifier continues to supply power to the load during operation in the low power mode.

主权项

1. A reconfigurable power amplifier comprising:
a first transformation network including first and second inputs and an output; a second transformation network including third and fourth inputs and an output; wherein said first and second transformation networks are coupled together to drive a load; a first radio frequency (RF) amplifier coupled to the first and second inputs of the first transformation network; a second RF amplifier coupled to the third and fourth inputs of the second transformation network, wherein in a first mode of operation the first and second RF amplifiers contribute RF power to the load; a first circuit to disable the first RF amplifier so that it does not contribute RF power to the load in a reconfigured mode of operation; and a second circuit to couple said first and second inputs of the first transformation network together in the reconfigured mode of operation; wherein a load impedance at the third and fourth inputs of the second transformation network is different between the first mode of operation and the reconfigured mode of operation.