本文提出一种改进的FM-CW SAR Frequency Scaling算法。FM-CW SAR由于大的脉冲持续时间和100%的信号占空比,使"停-走-停"模式失效。本文针对FM-CW SAR的信号处理特点,如载机在大扫频周期内运动引起的快时间距离走动问题及传...本文提出一种改进的FM-CW SAR Frequency Scaling算法。FM-CW SAR由于大的脉冲持续时间和100%的信号占空比,使"停-走-停"模式失效。本文针对FM-CW SAR的信号处理特点,如载机在大扫频周期内运动引起的快时间距离走动问题及传统算法应用在FM-CW SAR中带来的频谱混叠问题进行深入讨论,改进的算法在校正快时间距离走动的同时,解决了频谱混叠问题,实现了目标精确成像。理论推导和仿真结果表明算法的可行性与正确性。展开更多
This paper presents the system design and experimental results of a 35GHz coherent LFM-CW radar for use in near range two-dimensional imaging. Special techniques, including FM sweep linearization, range-segment proces...This paper presents the system design and experimental results of a 35GHz coherent LFM-CW radar for use in near range two-dimensional imaging. Special techniques, including FM sweep linearization, range-segment processing, system background voltage suppression and dynamic range compression are also presented.展开更多
This paper presented an automatic gain control(AGC) circuit suitable for FM/cw ladar. The proposed architecture was based on two-stage variable gain amplifier(VGA) chain with a novel DC offset canceller circuit, which...This paper presented an automatic gain control(AGC) circuit suitable for FM/cw ladar. The proposed architecture was based on two-stage variable gain amplifier(VGA) chain with a novel DC offset canceller circuit, which contained an improved Gilbert cell and a Gm-C feedback loop. To keep the VGA with a linearity in dB characteristic, an improved exponential gain control circuit was introduced. The AGC was implemented in 0.18 μm standard CMOS process. Simulation and measurement results verified that its gain ranged from-20 dB to 30 dB, and bandwidth ranged from 100 kHz to 10 MHz. Its power consumption was 19.8 mW under a voltage supply of 3.3 V.展开更多
文摘本文提出一种改进的FM-CW SAR Frequency Scaling算法。FM-CW SAR由于大的脉冲持续时间和100%的信号占空比,使"停-走-停"模式失效。本文针对FM-CW SAR的信号处理特点,如载机在大扫频周期内运动引起的快时间距离走动问题及传统算法应用在FM-CW SAR中带来的频谱混叠问题进行深入讨论,改进的算法在校正快时间距离走动的同时,解决了频谱混叠问题,实现了目标精确成像。理论推导和仿真结果表明算法的可行性与正确性。
文摘This paper presents the system design and experimental results of a 35GHz coherent LFM-CW radar for use in near range two-dimensional imaging. Special techniques, including FM sweep linearization, range-segment processing, system background voltage suppression and dynamic range compression are also presented.
基金Supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2012ZX03004008)
文摘This paper presented an automatic gain control(AGC) circuit suitable for FM/cw ladar. The proposed architecture was based on two-stage variable gain amplifier(VGA) chain with a novel DC offset canceller circuit, which contained an improved Gilbert cell and a Gm-C feedback loop. To keep the VGA with a linearity in dB characteristic, an improved exponential gain control circuit was introduced. The AGC was implemented in 0.18 μm standard CMOS process. Simulation and measurement results verified that its gain ranged from-20 dB to 30 dB, and bandwidth ranged from 100 kHz to 10 MHz. Its power consumption was 19.8 mW under a voltage supply of 3.3 V.
