快速自动增益控制(Automatic Gain Control,AGC)系统可以扩大接收机的动态范围,同时保证系统响应时间。本文提出了一种快速峰值检测算法,并应用于实际AGC系统。首先分析了快速峰值检测算法的准确性,然后进行计算机仿真,最后完成了基于F...快速自动增益控制(Automatic Gain Control,AGC)系统可以扩大接收机的动态范围,同时保证系统响应时间。本文提出了一种快速峰值检测算法,并应用于实际AGC系统。首先分析了快速峰值检测算法的准确性,然后进行计算机仿真,最后完成了基于FPGA的快速AGC系统硬件实现。理论分析,计算机仿真及硬件测试证明,应用快速峰值检测算法的AGC系统响应时间可达微秒级。展开更多
In this paper, we present a new method to determine the relative permittivity of periodic stratified media using the iterative time-reversal method. Based on transmission line theory, the focal peak value of iterative...In this paper, we present a new method to determine the relative permittivity of periodic stratified media using the iterative time-reversal method. Based on transmission line theory, the focal peak value of iterative time-reversal electro- magnetic waves, which contain information about the periodic stratified medium, is computed in pulse-echo mode. Using the relationship between the focal peak value and the relative permittivity of the periodic stratified medium, the relative permittivity can be obtained by measuring the focal peak value. Numerical simulations are conducted, and the results demonstrate the feasibility of the proposed approach to the measurement of the relative permittivity of a periodic stratified medium.展开更多
文摘快速自动增益控制(Automatic Gain Control,AGC)系统可以扩大接收机的动态范围,同时保证系统响应时间。本文提出了一种快速峰值检测算法,并应用于实际AGC系统。首先分析了快速峰值检测算法的准确性,然后进行计算机仿真,最后完成了基于FPGA的快速AGC系统硬件实现。理论分析,计算机仿真及硬件测试证明,应用快速峰值检测算法的AGC系统响应时间可达微秒级。
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61071031,61107018,and 61201089)the Research Fund for the Doctoral Program of Higher Education of China(Grant Nos.20100185110021 and 20120185130001)+2 种基金the Program for Changjiang Scholars and Innovation Team in University,China(Grant No.IRT1113)the Natural Science Foundation of the Higher Education Institutions of Anhui Province(Grant No.KJ2013Z287)Fundamental Research Fund for the Central Universities(Grant No.ZYGX2011YB018)
文摘In this paper, we present a new method to determine the relative permittivity of periodic stratified media using the iterative time-reversal method. Based on transmission line theory, the focal peak value of iterative time-reversal electro- magnetic waves, which contain information about the periodic stratified medium, is computed in pulse-echo mode. Using the relationship between the focal peak value and the relative permittivity of the periodic stratified medium, the relative permittivity can be obtained by measuring the focal peak value. Numerical simulations are conducted, and the results demonstrate the feasibility of the proposed approach to the measurement of the relative permittivity of a periodic stratified medium.
