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A fully integrated dual-band RF receiver with a low-IF architecture is designed and implemented for GPS-L 1 and Compass-Bl in a 55-nm CMOS process. The receiver incorporates two independent IF channels with 2 or 4 MHz bandwidth to receive dual-band signals around 1.57 GHz respectively. By implementing a flexible frequency plan, the RF front-end and frequency synthesizer are shared for the dual-band operation to save power consumption and chip area, as well as avoiding LO crosstalk. A digital automatic gain control (AGC) loop is utilized to improve the receiver's robustness by optimizing the conversion gain of the analog-to-digital converter (ADC). While drawing about 20 mA per channel from a 1.2 V supply, this RF receiver achieves a minimum noise figure (NF) of about 1.8 dB, an image rejection (IMR) of more than 35 dB, a maximum voltage gain of about 122 dB, a gain dynamic range of 82 dB, and an maximum input-referred 1 dB compression point of about -36.5 dBm with an active die area of 1.5 × 1.4 mm2 for the whole chip. 相似文献
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导弹防御系统中的目标综合识别模型 总被引:2,自引:0,他引:2
目标识别是导弹防御系统的支撑技术,本文参考导弹防御系统配置,建立了基于时空信息序贯融合的综合识别数学模型,将专家知识、环境信息以及测量信息共同纳入综合识别流程。在空间域融合中,利用层次分析法度量了各技术途径的可靠性,并基于技术途径的可靠性和识别结果的一致性提出了“融合权重”的概念,用于度量各技术途径参与融合识别的重要程度:在时间域融合中,将D-S证据理论应用于融合识别结果的继承和更新。仿真实验结果表明,综合识别模型能够有效融合多个技术途径的局部决策,抑制个别奇异结果,具有较好的容错性能。 相似文献
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群时延是衡量传输网络对信号传输时间延迟及信号失真影响的重要参数.基于微分(差分)的传统群时定义和测量存在如下缺点:存在分辨率与精度之间的矛盾,不能反映一定带宽内的整体相位特性,难以定量描述相位的非线性畸变.为了解决这些问题,本文从相频特性整体出发,基于Taylor展开给出了一种新的群时延的定义和测量方法.在GPS授时接收机电缆传输特性测试中的实验结果表明,新测量方法测得的群时延达到了0.01ns的测量精度,与GPS授时接收机测得的信号传输时延之间最大偏差不超过0.3ns,具有良好的对应关系. 相似文献
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