POWER AMPLIFIER IN ORTHOGONAL FREQUENCY DIVISION MULTIPLE ACCESS SYSTEMS

摘要

A power amplifier in orthogonal frequency division multiple access systems is provided to prevent deterioration of an ACLT(Adjacent Channel Leakage Ratio) due to spectral regrowth by offering a high DC bias in a preamble section with high power boosting. In a power amplifier in orthogonal frequency division multiple access systems, a power amplifier(210) amplifies an RF signal into high power to output the amplified RF signal. A controlling unit(220) receives a TDD control signal and outputs a control signal for each section by counting from the starting point of the TDD control signal for a predetermined section. A switching modulator(230) receives the control signal for each section from the controlling unit(220) and outputs a pulse signal for each section. A DC-DC converter(240) receives the pulse signal for each section from the switching modulator(230) and provides a different DC bias according to each pulse signal to the power amplifier(210).