Patent ID: 8219043
Filing Date: 2012-07-10
Classification: H03F,H04B

Abstract:
1. A radio transmission apparatus for transmitting a transmission signal by radio, the radio transmission apparatus comprising: an amplification section that generates a transmission signal by a signal amplification process; a power supply section that supplies an electric power to the amplification section; an antenna that transmits the transmission signal generated by the amplification section; a current detection section that detects an output current of the power supply section that varies in response to a variation of an output impedance of the amplification section; an LUT holding section that holds: a standard table that corrects a distortion of an input/output characteristic of the amplification section that is obtained when the output current of the power supply section is within a predetermined range; and a correction table that corrects a distortion of the input/output characteristic of the amplification section that is obtained when the output current of the power supply section is greater than the predetermined range; a distortion correction section that adjusts a signal inputted to the amplification section, based on the standard table or the correction table to correct a distortion of the input/output characteristic of the amplification section; and a distortion control section that instructs the distortion correction section: to use the standard table until the output current of the power supply section exceeds a first threshold that is an upper limit of the predetermined range; to use the correction table from the time when the output current of the power supply section exceeds the first threshold to the time when the output current of the power supply section becomes less than a second threshold that is less than the first threshold; and to use the standard table from the time when the output current of the power supply section becomes less than the second threshold to the time when the output current of the power supply section exceeds the first threshold again.