Ma M T, Adams J W
National Institute of Standards and Technology, Boulder, CO 80303-3328.
J Res Natl Inst Stand Technol. 1993 May-Jun;98(3):297-319. doi: 10.6028/jres.098.025.
A method is presented for predicting the total response, in both frequency and time, of an unknown linear system when only the measured continuous wave (cw) magnitude is available. The approach is based on approximating the square of the measured magnitude by a rational function, from which various system transfer functions in terms of complex frequency are deduced. These transfer functions may or may not be at minimum phase. The corresponding impulse response is then obtained by taking the inverse Laplace transform of the transfer function. The impulse response of the minimum-phase case rises faster initially to its first maximum than the nonminimum-phase counterparts. This result confirms that, for the same cw magnitude response, the accumulative energy contained in the impulse response is the greatest when the transfer function is at minimum phase. Physical meaning of the energy content is also discussed.
提出了一种在仅已知测量的连续波（cw）幅度时预测未知线性系统在频率和时间上的总响应的方法。该方法基于用有理函数逼近测量幅度的平方，由此推导出各种关于复频率的系统传递函数。这些传递函数可能是最小相位的，也可能不是。然后通过对传递函数进行拉普拉斯逆变换来获得相应的脉冲响应。最小相位情况下的脉冲响应最初比非最小相位情况更快地上升到其第一个最大值。该结果证实，对于相同的cw幅度响应，当传递函数为最小相位时，脉冲响应中包含的累积能量最大。还讨论了能量含量的物理意义。
