共查询到18条相似文献,搜索用时 859 毫秒
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浅谈WCDMA发射频段无源互调失真的测量 总被引:1,自引:0,他引:1
由两个频率产生的三阶互调失真是现代通信系统中普遍存在的问题。当系统中两个(或更多)的载频信号通过一个无源器阿件,如天线、电缆、滤波器和双工器时,由于其机械接触的不可靠、虚焊和表面氧化等原因,在不同材料的连接处会产生非线性因素,这就像混频二极管。两个载频信号(F1和F2)及其二次谐波(2F1和2F2)所进一步产生的最大互调产物就是三阶互调失真(2F1-F2和2F2-F1)。三阶互调产物(IM3)的典型指标是当两个 43dBm的载频信号同时加到被测器件(DUT)时,其产生的IM3值不大于-110dBm,也就是-153dBc。三阶互调失真会降低通信系统的性能。… 相似文献
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通过专用无源互调分析仪对微带传输线的无源互调(Passive Intermodulation,PIM)效应进行了初步实验研究.在不同微波介质基材上设计并加工了特征阻抗为50Ω的不同长度的微带传输线,通过专用无源互调分析仪进行PIM测试.实验结果表明:输入载波功率每增加1dB,三阶PIM产物功率增加约2.7dB;三阶PIM产物有随载波频率增加而减小的趋势;微带传输线越长,则PIM产物功率越大;微波介质材料对PIM产物也有一定影响.所得实验规律对高性能微波集成电路设计具有借鉴意义. 相似文献
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由两个频率产生的三阶互调失真是现代通信系统中普遍存在的问题。当系统中两个(或更多)的载频信号通过一个无源器阿件,如天线、电缆、滤波器和双工器时,由于其机械接触的不可靠.虚焊和表面氧化等原因,在不同材料的连接处会产生非线性因素,这就像混频二极管。两个载频信号(F1和F2)及其二次谐波(2F1和2F2)所进一步产生的最大互调产物就是三阶互调失真(2F1-F2和2F2-F1)。三阶互调产物(IM3)的典型指标是当两个 43dBm的载频信号同时加到被测器件(DUT)时,其产生的IM3值不大于-110dBm,也就是-153dBc。 相似文献
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射频模拟预失真器的研究与设计 总被引:1,自引:0,他引:1
利用小信号BJT放大器的非线性特性设计了一个有源模拟预失真器.通过调整小信号放大器的偏置状态和对失真信号的提取控制,使功放的三阶互调失真得到了明显的改善.双音实测数据表明,该预失真器使一个GSM基站功放在5 dB功率回退点附近的三阶互调失真改善了18 dB左右,与传统的射频预失真器相比,该预失真器对功放三阶互调失真的改善度提高了10 dB左右. 相似文献
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A. M. Bobreshov L. I. Averina N. N. Mymrikova A. V. Tagiev D. V. Gluschenko 《Radioelectronics and Communications Systems》2010,53(10):555-561
The tool of nonstationary Volterra series has been applied for analyzing a semiconductor parametric amplifier. The gain factor
and the intermodulation product of the third order were calculated at different parameters of the device circuit 相似文献
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基于布拉格衍射和相干光探测原理,分析了入射光和衍射光的特性及数学关系,讨论了如何利用声光偏转器实现信号处理的方法.从改善空间相干光探测效率出发,提出一种将空间光经声光衍射后注入保偏光纤的处理方法,克服了传统相干探测中光偏振态难控制的缺点,减小了外界环境对信号光和参考光合路的影响,降低了光学系统的调整环节中的难度,有效地解决了相干光探测中光束对准和偏振光的保持问题.实验证明,在保证一定的耦合光孔径和激光注入效率条件下,将空间光注入保偏光纤,削弱了背景光对合路产生的影响,使信号光和参考光偏振态和传输方向能更好保持,极大改善了空间相干光探测效率,提高了光电探测信噪比. 相似文献
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Kito M. Sato H. Otsuka N. Takenaka N. Ishino M. Matsui Y. 《Photonics Technology Letters, IEEE》1995,7(2):144-146
Analysis of second and third order intermodulation distortion characteristics of semiconductor DFB lasers is, for the first time, performed, including dynamic longitudinal spatial hole burning (LSHB) effect. We have shown theoretically that the third order intermodulation distortion can be lower than the calculated curve without LSHB effect, which is confirmed with experiments 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1966,54(11):1528-1535
In this paper exact formulas are found for the intermodulation generated in a semiconductor diode junction, and a method is developed to make the calculation of the intermodulation practicable. This method generates the intermodulation output spectrum by operating on the signal input spectrum with convolution. This method lends itself to tabular, graphical, or computer solutions, and the results can be easily interpreted. In the past the detailed calculation of intermodulation product amplitudes was a formidable task. With the techniques of this paper it should be possible to make these calculations routine. It will be feasible to determine RFI compatibility of new frequency allocations ahead of time, analyze existing RFI problems, and design receivers to work in severe interference environments. Equations are derived for the total intermodulation at a specific frequency, and for the spectrum of each order of intermodulation due to either CW or quasi-continuous input spectra. Examples are given of cross modulation, intermodulation, distortion, and third-order products. 相似文献