共查询到19条相似文献,搜索用时 46 毫秒
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介绍新的带外信号检测方法和自适应模拟预失真线性化技术,并应用于CDMA直放站的5W自适应射频线性功率放大器.为了有效抑制临信道频谱再生,通过自适应检测和自适应预失真控制使输出信号的3阶和5阶交调失真分别改善8dBc和6dBc. 相似文献
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使用自适应RF预失真技术改善放大器线性的研究 总被引:3,自引:0,他引:3
RF功率放大器对信号造成的非线性失真会产生邻道干扰,并降低信号质量,因此宽带通信系统对功率放大器的线性提出了严格的要求。本文提出了可以改善功率放大器线性的自适应RF预失真电路的模型,描述了自适应RF预失真的实现过程;介绍了现有的一些自适应预失真技术,具体分析了常用的矩形功函数预失真技术和最小功率自适应方法;通过仿真进一步证明了预失真技术可大大提高RF功率放大器的线性度。 相似文献
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射频功率放大器的线性化技术 总被引:1,自引:0,他引:1
李军 《信息技术与信息化》2003,(4):29-30
本文阐述了射频功率放大器非线性产生的原因 ,介绍了几种射频功放的线性化技术 ,以便于射频功放设计者参考 相似文献
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介绍了射频功率放大器的自适应前馈技术以及几种自适应前馈控制方法.并利用梯度法时射频功率放大器进行自适应前馈调整.使其线性度得到明显改变。 相似文献
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Ai Bo Zhong Zhang-Dui Zhu Gang Yang Yan Xu Rong-Tao 《Wireless Personal Communications》2008,46(4):523-530
Polynomial predistortion techniques for power amplifier (PA) non-linearities based on indirect learning architecture (IDLA)
are widely used. The benefit of the IDLA leaves unnecessary the assumption of a model for PA, corresponding parameters estimation
and inverse construction. In this paper, a novel scheme based on IDLA for PA predistortion is proposed. It has better power
spectral density (PSD) and relative mean square error (RMSE) performances than the conventional IDLA-based methods especially
when the PA non-liearity is more severe. Simulations and theoretical analysis verify the good performances of the proposed
scheme.
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Ai BoEmail: |
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Radio frequency (RF) power amplifiers (PA) are the most power consuming components of a mobile communications unit. They are used to convert the DC power from the battery into RF power delivered to the antenna. In a cell phone it becomes very important to use highly efficient power amplifiers, such as Class C and Class E PAs, to increase the talk time which is directly proportional to the battery life. On the other hand, these RF PAs are inherently nonlinear and produce spectral regrowth and other undesirable effects. Therefore, to exploit their high efficiency, it is desirable to employ linearization techniques to linearize their overall response. Linear model matching linearization techniques are investigated in this work to compensate for PA nonlinearities. The application of these techniques results in a controller architecture that delivers excellent linearity performance of compensated Class C PA models, making them very suitable in wideband digital communication systems that transmit multiple signals at high data rates, assuring that intermodulation distortion and spectral regrowth are minimized at the output of the power amplifier. 相似文献
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本文提出了一种基于预失真技术的短波功率放大器线性化系统的设计方案,该方案采用查找表技术,且使用了一种独特的放大特性测量方法,具有很强的实用性。 相似文献
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Roblin P. Suk Keun Myoung Chaillot D. Young Gi Kim Fathimulla A. Strahler J. Bibyk S. 《Microwave Theory and Techniques》2008,56(1):65-76
This paper presents a frequency-selective RF vector predistortion linearization system for RF multicarrier power amplifiers (PAs) affected by strong differential memory effects. Differential memory effects can be revealed in two-tone experiment by the divergence for increasing tone-spacing of the vector Volterra coefficients associated with the lower and upper intermodulations tones. Using large-signal vector measurement with a large-signal network analyzer, a class-AB LDMOS RF PA is demonstrated to exhibit a strong differential memory effect for modulation bandwidth above 0.3 MHz. New frequency-selective RF and baseband predistortion linearization algorithms are proposed to separately address the linearization requirements of the interband and inband intermodulation products of both the lower and upper sidebands. Theoretical verification of the algorithms are demonstrated with Matlab simulations using a Volterra/Wiener PA model with memory effects. The baseband linearization algorithm is next implemented in a field-programmable gate array and experimentally investigated for the linearization of the class-AB LDMOS PA for two carrier wideband code-division multiple-access signals. The ability of the algorithm to selectively linearize the two interband and four inband intermodulation products is demonstrated. Adjacent channel leakage ratio of up to 45 dBc for inband and interband are demonstrated experimentally at twice the typical fractional bandwidth. 相似文献