The Ocean 4A scatterometer, expected to be launched in 2024, is poised to be the world’s first spaceborne microwave scatterometer utilizing a digital beamforming system. To ensure high-precision measurements and perf...The Ocean 4A scatterometer, expected to be launched in 2024, is poised to be the world’s first spaceborne microwave scatterometer utilizing a digital beamforming system. To ensure high-precision measurements and performance sta-bility across diverse environments, stringent requirements are placed on the dynamic range of its receiving system. This paper provides a detailed exposition of a field-programmable gate array (FPGA)-based automatic gain control (AGC) design for the spaceborne scatterometer. Implemented on an FPGA, the algo-rithm harnesses its parallel processing capabilities and high-speed performance to monitor the received echo signals in real time. Employing an adaptive AGC algorithm, the system gene-rates gain control codes applicable to the intermediate fre-quency variable attenuator, enabling rapid and stable adjust-ment of signal amplitudes from the intermediate frequency amplifier to an optimal range. By adopting a purely digital pro-cessing approach, experimental results demonstrate that the AGC algorithm exhibits several advantages, including fast con-vergence, strong flexibility, high precision, and outstanding sta-bility. This innovative design lays a solid foundation for the high-precision measurements of the Ocean 4A scatterometer, with potential implications for the future of spaceborne microwave scatterometers.展开更多
近年来电网对火电机组自动发电控制(automatic gain control,AGC)响应能力提出日益严苛的要求。针对火电机组快速变负荷问题提出一种基于凝结水节流的AGC负荷控制策略。设计协调补偿系统对机炉侧和节流侧功率控制进行解耦,基于锅炉热量...近年来电网对火电机组自动发电控制(automatic gain control,AGC)响应能力提出日益严苛的要求。针对火电机组快速变负荷问题提出一种基于凝结水节流的AGC负荷控制策略。设计协调补偿系统对机炉侧和节流侧功率控制进行解耦,基于锅炉热量信号计算节流功率增量定值,基于节流功率反馈模型对机炉侧负荷控制补偿。在源网联合仿真平台上对改进的AGC响应控制策略进行仿真评估,结果证明,该策略能够在连续稳定控制凝结水节流系统的同时,有效改善火电机组AGC考核指标和控制性能标准(control performance standard,CPS)考核指标,提高火电机组参与电网AGC调节的能力。展开更多
自动增益控制(automatic gain control,AGC)可以满足强干扰场景下非合作干扰对消系统对高动态的要求,如何定量表征其对干扰对消性能的影响,是指导多通道AGC方案设计的关键。通过谱分析与特征子空间的方法推导得到AGC的稳态增益与自相关...自动增益控制(automatic gain control,AGC)可以满足强干扰场景下非合作干扰对消系统对高动态的要求,如何定量表征其对干扰对消性能的影响,是指导多通道AGC方案设计的关键。通过谱分析与特征子空间的方法推导得到AGC的稳态增益与自相关矩阵特征值的映射关系,建立干扰对消权值的瞬态模型。基于干扰对消权值的解析表达式,详细分析稳态增益对干扰对消性能的影响规律,揭示了稳态增益与稳定性、收敛速度以及对消比之间的定量关系。同时,进一步研究AGC的调控过程初始增益、步长、平均步长时间、多通道控制策略对干扰对消瞬态收敛特性的影响,可以有效指导多通道AGC方案设计。仿真结果验证了权值瞬态模型的正确性以及干扰对消性能分析结论的有效性。实验结果表明,理论与仿真的分析结论可以用来指导AGC方案的工程实践。展开更多
文摘The Ocean 4A scatterometer, expected to be launched in 2024, is poised to be the world’s first spaceborne microwave scatterometer utilizing a digital beamforming system. To ensure high-precision measurements and performance sta-bility across diverse environments, stringent requirements are placed on the dynamic range of its receiving system. This paper provides a detailed exposition of a field-programmable gate array (FPGA)-based automatic gain control (AGC) design for the spaceborne scatterometer. Implemented on an FPGA, the algo-rithm harnesses its parallel processing capabilities and high-speed performance to monitor the received echo signals in real time. Employing an adaptive AGC algorithm, the system gene-rates gain control codes applicable to the intermediate fre-quency variable attenuator, enabling rapid and stable adjust-ment of signal amplitudes from the intermediate frequency amplifier to an optimal range. By adopting a purely digital pro-cessing approach, experimental results demonstrate that the AGC algorithm exhibits several advantages, including fast con-vergence, strong flexibility, high precision, and outstanding sta-bility. This innovative design lays a solid foundation for the high-precision measurements of the Ocean 4A scatterometer, with potential implications for the future of spaceborne microwave scatterometers.
文摘近年来电网对火电机组自动发电控制(automatic gain control,AGC)响应能力提出日益严苛的要求。针对火电机组快速变负荷问题提出一种基于凝结水节流的AGC负荷控制策略。设计协调补偿系统对机炉侧和节流侧功率控制进行解耦,基于锅炉热量信号计算节流功率增量定值,基于节流功率反馈模型对机炉侧负荷控制补偿。在源网联合仿真平台上对改进的AGC响应控制策略进行仿真评估,结果证明,该策略能够在连续稳定控制凝结水节流系统的同时,有效改善火电机组AGC考核指标和控制性能标准(control performance standard,CPS)考核指标,提高火电机组参与电网AGC调节的能力。
文摘自动增益控制(automatic gain control,AGC)可以满足强干扰场景下非合作干扰对消系统对高动态的要求,如何定量表征其对干扰对消性能的影响,是指导多通道AGC方案设计的关键。通过谱分析与特征子空间的方法推导得到AGC的稳态增益与自相关矩阵特征值的映射关系,建立干扰对消权值的瞬态模型。基于干扰对消权值的解析表达式,详细分析稳态增益对干扰对消性能的影响规律,揭示了稳态增益与稳定性、收敛速度以及对消比之间的定量关系。同时,进一步研究AGC的调控过程初始增益、步长、平均步长时间、多通道控制策略对干扰对消瞬态收敛特性的影响,可以有效指导多通道AGC方案设计。仿真结果验证了权值瞬态模型的正确性以及干扰对消性能分析结论的有效性。实验结果表明,理论与仿真的分析结论可以用来指导AGC方案的工程实践。
