S类功放的频率可调带通ΔΣ调制器研究与实现
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摘要
S类射频功率放大器同时具有高效率和高线性特性,适合在全数字发信机中应用。但需要将任意输入的射频信号转换为两电平脉冲调制信号,带通增量求和(ΔΣ)调制才可以很好地实现上述功能。为实现S类功放的宽频带工作,带通ΔΣ调制器的中心频率必须实现与输入信号频率的实时跟随。通过对ΔΣ调制算法的研究,提出了一种频率可调带通ΔΣ调制器的设计方法,并利用Matlab软件和FPGA对设计的调制器分别进行了仿真和实验验证。验证结果证明了该设计方法的可行性和有效性。
Class-S RF power amplifiers have gained interest in all-digital transmitter, due to their promising features of high efficiency and high linearity. It is necessary to convert the arbitrarily RF input signal into a two-level pulse modulated signal. This can be accomplished by band-pass delta-sigma( ΔΣ) modulation. To achieve the efficient amplification for broadband RF signal, the center frequency of the modulator must be real time to follow the input signal frequency. In this paper, based on the study of theΔΣ modulation algorithm, the design method of the band-pass ΔΣ modulator with tunable frequency is proposed. The simulation of this modulator is validated by Matlab. Finally, based on FPGA, an experiment circuit for the modulator is implemented. The simulations and experiments verify the feasibility and effectiveness of this method.
Class-S RF power amplifiers have gained interest in all-digital transmitter, due to their promising features of high efficiency and high linearity. It is necessary to convert the arbitrarily RF input signal into a two-level pulse modulated signal. This can be accomplished by band-pass delta-sigma( ΔΣ) modulation. To achieve the efficient amplification for broadband RF signal, the center frequency of the modulator must be real time to follow the input signal frequency. In this paper, based on the study of theΔΣ modulation algorithm, the design method of the band-pass ΔΣ modulator with tunable frequency is proposed. The simulation of this modulator is validated by Matlab. Finally, based on FPGA, an experiment circuit for the modulator is implemented. The simulations and experiments verify the feasibility and effectiveness of this method.
引文
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[2]GREBENNIKOV A,SOKAL N O.Switchmode RF power amplifiers[M].Oxford:Elsevier Inc.,2007.
[3]IWAMOTO M,JAYARAMAN A,HANINGTON G,et al.Bandpass delta-sigma Class-S amplifier[J].IEEE electronics letters,2000,36(12):1010-1012.
[4]NIELSEN M,LARSEN T.A transmitter architecture based on delta-sigma modulation and switch-mode power amplification[J].IEEE Transactions on Circuits and Systems II:Express Briefs,2007,54(8):735-739.
[5]朱蕾,周强,谭笑.基于多比特带通增量求和调制的射频数字功放[J].电子技术应用,2013,39(8):102-104.
[6]SCHREIER R,TEMES G C.Delta sigma数据转换器[M].北京:科学出版社,2007.
[2]GREBENNIKOV A,SOKAL N O.Switchmode RF power amplifiers[M].Oxford:Elsevier Inc.,2007.
[3]IWAMOTO M,JAYARAMAN A,HANINGTON G,et al.Bandpass delta-sigma Class-S amplifier[J].IEEE electronics letters,2000,36(12):1010-1012.
[4]NIELSEN M,LARSEN T.A transmitter architecture based on delta-sigma modulation and switch-mode power amplification[J].IEEE Transactions on Circuits and Systems II:Express Briefs,2007,54(8):735-739.
[5]朱蕾,周强,谭笑.基于多比特带通增量求和调制的射频数字功放[J].电子技术应用,2013,39(8):102-104.
[6]SCHREIER R,TEMES G C.Delta sigma数据转换器[M].北京:科学出版社,2007.