Based on the analysis of the spurious introduced by phase accumulation truncation which was made by Nicholas, a new simplified algorithm for spurious spectrum in the presence of phase truncation is presented by using ...Based on the analysis of the spurious introduced by phase accumulation truncation which was made by Nicholas, a new simplified algorithm for spurious spectrum in the presence of phase truncation is presented by using the mapping mathematics and number theoretic method, it is possible to precisely analyze the spurious location and the spurious amplitude introduced by phase truncation in practical applications by computer.展开更多
设计了一种基于正交调制原理的数字频率特性测试仪,系统用稳态响应法测量电路的频率特性.单片机作为主控芯片,完成系统的总体控制及数字信号处理;使用集成的直接数字频率合成芯片输出全频率范围内的正弦波.系统对待测电路的输入信号及...设计了一种基于正交调制原理的数字频率特性测试仪,系统用稳态响应法测量电路的频率特性.单片机作为主控芯片,完成系统的总体控制及数字信号处理;使用集成的直接数字频率合成芯片输出全频率范围内的正弦波.系统对待测电路的输入信号及其输出响应采样,经数字信号处理后,获得电路的幅频特性和相频特性.设计的测试仪测某RLC网络,中心频率的相对误差小于0.2%,有载品质因数相对误差小于1.25%,最大电压增益大于-1 d B.频率特性测试仪输入输出阻抗均为50Ω,幅频误差绝对值小于0.5 d B,相频误差绝对值小于3°,测试仪能满足微机械谐振传感器特征参数测试需求.展开更多
本文提出了一种直接数字频率合成器(DDFS)的设计,以Parallel_CORDIC(COrdinate Rotation Digital Computer)算法模块替代传统的查找表方式,实现了相位与幅度的一一对应,输出相位完全正交的正余弦波形;同时应用旋转角度预测及4:2的进位...本文提出了一种直接数字频率合成器(DDFS)的设计,以Parallel_CORDIC(COrdinate Rotation Digital Computer)算法模块替代传统的查找表方式,实现了相位与幅度的一一对应,输出相位完全正交的正余弦波形;同时应用旋转角度预测及4:2的进位保存加法器(CSA)技术,将速度比传统CORDIC算法提高41.7%,精度提高到10-4.最后以Xilinx的FPGA硬件实现整个设计.展开更多
文摘Based on the analysis of the spurious introduced by phase accumulation truncation which was made by Nicholas, a new simplified algorithm for spurious spectrum in the presence of phase truncation is presented by using the mapping mathematics and number theoretic method, it is possible to precisely analyze the spurious location and the spurious amplitude introduced by phase truncation in practical applications by computer.
文摘设计了一种基于正交调制原理的数字频率特性测试仪,系统用稳态响应法测量电路的频率特性.单片机作为主控芯片,完成系统的总体控制及数字信号处理;使用集成的直接数字频率合成芯片输出全频率范围内的正弦波.系统对待测电路的输入信号及其输出响应采样,经数字信号处理后,获得电路的幅频特性和相频特性.设计的测试仪测某RLC网络,中心频率的相对误差小于0.2%,有载品质因数相对误差小于1.25%,最大电压增益大于-1 d B.频率特性测试仪输入输出阻抗均为50Ω,幅频误差绝对值小于0.5 d B,相频误差绝对值小于3°,测试仪能满足微机械谐振传感器特征参数测试需求.
文摘本文提出了一种直接数字频率合成器(DDFS)的设计,以Parallel_CORDIC(COrdinate Rotation Digital Computer)算法模块替代传统的查找表方式,实现了相位与幅度的一一对应,输出相位完全正交的正余弦波形;同时应用旋转角度预测及4:2的进位保存加法器(CSA)技术,将速度比传统CORDIC算法提高41.7%,精度提高到10-4.最后以Xilinx的FPGA硬件实现整个设计.
