共查询到19条相似文献,搜索用时 62 毫秒
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高频头是一种数字卫星电视信号接收装置,它能对卫星接收信号进行变频和放大.介绍一种Ku双本振多输出高频头的工作原理、性能指标、仿真结果、技术难点、实测结果,并在工程实践中实现批量化生产. 相似文献
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该文介绍一种多模终端综测仪的小型化本振设计,首先简介了本振的内部结构以及内部每个模块的基本原理,并针对此本振采用有源环路滤波器形式设计了环路参数,理论分析了相位噪声以及如何设计杂散抑制,最后获得测试结果验证了小型化本振有较好的相位噪声,达到了预期的目标. 相似文献
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针对工程中本振相位噪声对接收机的影响常难以估量的问题,提出利用等效相位白噪声谱密度进行评估的方法.通过分析相位噪声的产生及其对剩余误码率和动态范围的影响机理,仿真了不同相位噪声对误码率的影响程度.通过仿真结果可知:相位噪声对接收机性能具有重要的影响,工程中应针对不同的应用场合要求合理的相位噪声指标. 相似文献
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卫星电视接收天线LNB的本振频率对于一定的接收系统在理论上是一个固定值,但实际上其值受到工作环境变化的影响会出现漂移;其次,由于所选用的LNB不同,本振频率与理论值的频偏不同。在实际的保障工作中,接收同一卫星信号,用不同的接收天线得到的中频不同,严重时会出现二者的频偏相差超过2 MHz,这样在更换备用天线时必须调整卫星电视解码器的参数设置。 相似文献
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应对时钟上升沿和下降沿均采集数据的芯片间高速接口,提出了一种输出占空比在50%左右、偏差范围±5%的支持SSTL_2标准的I/O缓冲器.利用互补有源电流镜差动对,实现在不同温度和工艺角下输出信号稳定的占空比偏差范围的输入接收器.为了验证电路实际工作性能,测试芯片在SMIC 0.18 μm 1P6M混合信号工艺下流片.测试结果显示,333 MHz时,输出占空比为47%;200 MHz时,输出占空比为48%;与已报道的支持SSTL_2标准的接收器相比,工作在333 MHz时,输出占空比仍保持在45%到55%间,偏差范围减小约72%. 相似文献
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设计了一种可工作于0.9 V低电压和-5 dBm本振功率的CMOS有源混频器.通过在MOS管栅极和衬底间引入耦合电容,利用衬底效应加快MOS管的导通和截止,使开关对的开关状态更理想,有效地降低混频器的噪声并提高其线性特性.采用0.18 μm CMOS工艺设计,在2.45 GHz本振信号和2.44 GHz射频信号输入下,实验结果表明该混频器可有效地实现混频且具有较好的性能指标:电压转换增益为12.4 dB,输入三阶截断点为-0.6 dBm,输入1dB压缩点为-3.4 dBm,单边带噪声系数为12 dB. 相似文献
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介绍了频谱分析仪中本振自动扫描的几种常用工作方式,给出了利用DDS来实现本振自动扫描的原理方法。论述了在实际工程中如何应用FPGA设计来实现本振的自动扫描,并给出了设计主要指标结果。 相似文献
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A down-conversion in-phase/quadrature (I/Q) mixer employing a folded-type topology, integrated with a passive differential quadrature all-pass filter (D-QAF), in order to realize the final down-conversion stage of a 60 GHz receiver architecture is presented in this work. Instead of employing conventional quadrature generation techniques such as a polyphase filter or a frequency divider for the local oscillator (LO) of the mixer, a passive D-QAF structure is employed. Fabricated in a 65 nm CMOS process, the mixer exhibits a voltage gain of 7-8 dB in an intermediate frequency (IF) band ranging from 10 MHz-1.75 GHz. A fixed LO frequency of 12 GHz is used to down-convert a radio frequency (RF) band of 10.25-13.75 GHz. The mixer displays a third order input referred intercept point (IIP3) ranging from -8.75 to -7.37 dBm for a fixed IF frequency of 10 MHz and a minimum single-sideband noise figure (SSB-NF) of 11.3 dB. The mixer draws a current of 6 mA from a 1.2 V supply voltage dissipating a power of 7.2 mW. 相似文献
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在当前许多复杂调制射频信号源中,随着数字基带信号越来越多的加入.需要正交凋制器将其调制到需要的载波信号上。正交调制器原理简单:将生成好的I/Q两路基带信号调制到两路正交的载波上,合路后输出。但是在实现时,想获得好的指标就需要考虑载波相位误差,I/Q基带信号幅度不平衡以及载波泄漏等问题。文章给出了一种正交调制器的校准方案,可以减少和模拟以上三种现象造成的调制误差,并给出自动校准和手动校准两种方法。 相似文献
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零中频处理缺陷分析及改进初探 总被引:1,自引:0,他引:1
在电子战系统中为了拓展信号处理带宽越来越多地采用I/Q变频体制,但是,在IQ变频体制中,当变频后的中频信号频率接近零时,信号检测和处理存在一些困难,有可能使系统性能下降。文章分析了IQ变频体制中零中频点对信号截获和干扰的影响,提出了改进措施,并对其可行性进行了分析,在改进零中频处理缺陷方面进行了有益的探索。 相似文献
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由于各种因素的影响,I/Q通道之间通常会发生失配现象,这会降低接收机的动态范围,进而影响接收机的性能。本文提出了一种宽带接收机中L/Q幅相误差校正的数字方法:首先通过一种时域方法以获得误差信息,籍此计算校正所需参数,再由Newton插值多项式构造滤波器组对I/Q信号进行滤波校正。仿真表明,这种数字校正方法能有效地提高宽带接收机I/Q通道的正交一致性。 相似文献
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A receiver for SRDs implemented by the 0.35μm CMOS process is presented. The receiver, together with the ADC, power amplifier (PA), frequency synthesizer and digital baseband has been integrated into a single chip solution. Low cost and low power requirements are met by optimizing the receiver architecture and circuit topology. A simple mixed-signal mode I/Q imbalance calibration circuit is proposed to enhance the IRR (image rejection ratio) so as to raise the BER. From a single 3 V power supply, the receiver consumes 5.9 mA. The measurement result shows that the receiver achieves reference sensitivity of-60 dBm and a control gain of 60 dB. The S11 reaches -20 dB at 433 MHz and -10 dB at 868 MHz without off-chip impedance match network. The die area is only 2 mm^2 including the bias circuit. 相似文献
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A receiver for SRDs implemented by the 0.35μm CMOS process is presented. The receiver, together with the ADC, power amplifier (PA), frequency synthesizer and digital baseband has been integrated into a single chip solution. Low cost and low power requirements are met by optimizing the receiver architecture and circuit topology. A simple mixed-signal mode I/Q imbalance calibration circuit is proposed to enhance the IRR (image rejection ratio) so as to raise the BER. From a single 3 V power supply, the receiver consumes 5.9 mA. The measurement result shows that the receiver achieves reference sensitivity of--60 dBm and a control gain of 60 dB. The S<,11> reaches-20 dB at 433 MHz and-10 dB at 868 MHz without off-chip impedance match network. The die area is only 2 mm2 including the bias circuit. 相似文献
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A novel I/Q mismatch calibration technique based on a digital baseband for a direct conversion transmitter is implemented in TSMC 0.13μm CMOS technology.The proposed technique finishes a calibration task, which only needs a calibration chain to detect mismatches and then transmit them to the digital baseband.Simulation results show that the calibrated errors of the proposed technique are less than 7%.The measurement results indicate the function of the proposed technique is correct,but the performance should be improved further. 相似文献
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