研究目的
To explore the influence of ES PA number of cells on the output signal distortion and its efficiency and to determine rational value of N.
研究成果
The rational choice of the number of cells (N=10...12) in multicell ES PAs increases efficiency by 2-4% compared to lower N values (e.g., N=4...6). Increasing N shifts intermodulation components to higher frequencies, reducing filter selectivity requirements or allowing lower q values to decrease switching losses. Parasitic harmonics are minimally affected by N but are significantly influenced by transistor switching time differences, limiting their reduction to around -60 dB. The use of switched-mode ES PAs does not degrade RF PA efficiency (maintained at 47%) and only slightly increases out-of-band spectrum distortion, with in-band performance remaining stable. This suggests that multicell structures are effective for improving efficiency and managing distortions in envelope tracking systems.
研究不足
The study is based on computer simulations and does not involve physical experiments, which may not fully capture real-world complexities. The models assume specific transistor characteristics (e.g., non-zero switching times), and the analysis is limited to harmonic and two-tone test signals, potentially not generalizing to all signal types. The paper notes that parasitic harmonics are difficult to reduce below -60 dB due to transistor imperfections, indicating a technical constraint. Future work could involve experimental validation and development of predistortion methods to further mitigate distortions.
1：Experimental Design and Method Selection:
The study uses computer simulation to analyze the efficiency and distortion of multicell envelope signal power amplifiers (ES PAs) and their impact on RF PAs. Theoretical models include equations for conduction and switching losses in transistors, and simulations are conducted for different numbers of cells (N) and frequency ratios (q).
2：Sample Selection and Data Sources:
A harmonic test signal is used for the envelope signal, and a two-tone test signal is employed for RF PA analysis. Models of class AB RF PA and single-sideband modulated signal are utilized.
3：List of Experimental Equipment and Materials:
The paper does not specify physical equipment; it relies on simulation models. Transistors with non-zero switching times and on-state voltage drops are considered in the models.
4：Experimental Procedures and Operational Workflow:
Simulations are performed for various N values (e.g., N=6, 12) and q values (e.g., q=10). Output voltage spectra are analyzed, and efficiency calculations are based on derived equations for power losses. Three cases are investigated for RF PA: constant supply voltage, ideal envelope source, and switched-mode ES PA supply.
5：0). Output voltage spectra are analyzed, and efficiency calculations are based on derived equations for power losses. Three cases are investigated for RF PA:
5. Data Analysis Methods: Efficiency is calculated using equations (1) and (2) for conduction and switching losses. Spectral analysis is used to measure distortion levels, such as intermodulation components and parasitic harmonics. Results are compared across different simulation scenarios.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
