Performance comparison of RF class-D amplifier with Neoteric modulator and bandpass sigma-delta modulator
Performance comparison of RF class-D amplifier with Neoteric modulator and bandpass sigma-delta modulator
复制标题
RF D 类放大器与 Neoteric 调制器和带通 Σ-Δ 调制器的性能比较
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
M. Chia
中科院分区：
文献类型：
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作者：
B. Shi;M. Chia
研究并比较了采用现代调制器和带通Σ-Δ调制器的射频D类放大器的性能。调制器将源信号编码为二进制电平脉冲序列，并将D类放大器的应用扩展到包括具有时变包络的信号。它们的性能与整个放大器的功率效率和线性度直接相关。调制器的两个重要参数，编码效率和平均过渡频率进行评估。在800 MHz下，使用峰值平均比为10.6dB的5 MHz W-CDMA信号和使用GaAs FET器件构建的D类放大器进行测试，发现该放大器使用Neoteric调制器实现了21%的功率效率，而带通Δ调制器的效率为11%，同时具有约− 45 dBc的可比水平的频谱增长。使用Neoteric调制器获得的更好的功率效率是由于其11.4%的更高的编码效率，而带通Δ调制器的编码效率为5.8%。
The performance of RF class-D amplification with Neoteric modulator and bandpass sigma-delta (ΣΔ) modulator are studied and compared. The modulators encode the source signal into a binary level pulse train, and broaden the application of class-D amplifiers to include signals with time-varying envelopes. Their performance are directly linked to the power efficiency and linearity of the overall amplifier. The modulators are evaluated in terms of two important parameters, coding efficiency and average transition frequency. Tested at 800MHz with a 5MHz W-CDMA signal having a 10.6dB peak-to-average ratio and a class-D amplifier constructed using GaAs FET devices, it is found that the amplifier achieves a power efficiency of 21% with Neoteric modulator, compared to an efficiency of 11% with bandpass ΣΔ modulator, while with comparable level spectral growth of around −45dBc. The better power efficiency obtained with Neoteric modulator is due to its higher coding efficiency of 11.4% versus 5.8% for the bandpass ΣΔ modulator.