使用改良的數位控制多爾蒂功率放大器之脈衝式極化發射機及其數位預失真

Abstract

無線通訊為了滿足對更高的資料傳輸速率，更好的頻譜效率以及更低的功耗而迅速演進。現代之基地台需要功率放大器在高效率運作的同時，仍保持高度線性以確保符合通訊規範。然而，傳統功率放大器設計常常難以滿足這些要求，特別是在處理高峰均功率比的複雜調變訊號時。 為解決這些挑戰，本論文設計一種多爾蒂放大器，並整合了脈衝調變信號以實現在功率回退的區間仍維持較高效率。此外，論文中還實現了兩種數位預失真技術，以減少非線性失真並提升傳輸訊號完整性。 根據量測之結果，此發射機在2.6 GHz中心頻率下，針對第五代新無線電(5GNR) n38，n41，n90等頻段，在功率回退範圍內的效率皆超過50%。調變訊號之量測結果顯示此發射機架構不僅能達到高效率，同時也能符合線性度之規範，展示了此架構在現代基地台無線通訊系統中的可行性。

Wireless communication systems have rapidly evolved to meet increasing demands for higher data rates, improved spectral efficiency, and lower power consumption. Modern base stations require power amplifiers (PAs) that operate efficiently while maintaining high linearity to ensure compliance with spectral emission regulations. However, conventional PA designs often struggle to meet these requirements, especially when handling complex modulation schemes with high peak-to-average power ratios (PAPR). To address these challenges, this thesis presents a carefully designed Doherty power amplifier (DPA), integrated with pulse modulation signals to achieve higher efficiency. Various digital predistortion (DPD) techniques are implemented to mitigate nonlinear distortions and improve signal integrity. The implemented transmitter achieves over 50% of efficiency within the backoff range at a 2.6 GHz center frequency, targeting the fifth generation new radio (5GNR) band n38, n41 and n90. Measurement results with a modulated signal demonstrate high efficiency while exceeding linearity specifications, showcasing the feasibility of the proposed transmitter for modern base station wireless communication systems.