A New Digital Predistortion for Wideband Power Amplifiers With Constrained Feedback Bandwidth

作者：Liu, Ying^*; Pan, Wensheng; Shao, Shihai; Tang, Youxi

来源：IEEE Microwave and Wireless Components Letters, 2013, 23(12): 683-685.

DOI：10.1109/LMWC.2013.2284786

• Digital predistortion (DPD)
• feedback bandwidth
• memory polynomial model
• power amplifier (PA)
• sampling rate

This letter presents a new digital predistortion (DPD) solution for wideband power amplifiers (PAs) with restricted feedback bandwidth and relatively low sampling rate. By integrating a microwave cavity filter into the feedback path, the feedback bandwidth is reduced efficiently. A PA parameter extraction method is then proposed to identify the PA model, using the bandwidth-constrained signals. By applying the extracted parameters to the direct learning architecture, the DPD function can be obtained, which can linearize nonlinear distortion over the sampling bandwidth. Experiments demonstrate that a 22 dB adjacent channel leakage ratio improvement is acquired for a 100 MHz Long Term Evolution-advanced signal, even when the feedback bandwidth is restricted from 500MHz to 100 MHz, which remarkably reduces the ADC sampling rate from 1105.92 Msps to 368.64 Msps.

• 出版日期2013-12
• 单位电子科技大学