针对利用阶跃响应法测试光电探测元件频率响应时存在无法获得相频特性的问题，文章通过Multisim软件建立了与实际器件参数一致的等效电路，根据相频特性中相位差与时间差之间的关系，提出了一种同时测量幅频特性和相频特性的频率响应测量方法，仿真测量的幅频特性结果与传统阶跃响应法的测量结果一致。光电二极管的相频特性对高速接收系统的设计具有重要影响。

This paper focuses on the inability to obtain the phase-frequency characteristics when testing the frequency response of photoelectric detecting elements by using the step response method. It sets up an equivalent circuit model that provides the same parameters as the actual devices by using the Multisim software and proposes a method for the simultaneous frequency response measurement of the amplitude-frequency and phase-frequency characteristics on the basis of the relationship between the phase difference and the time difference of the phase-frequency characteristics. The measurement results of amplitude-frequency characteristics are consistent with those by using the traditional step response method. The phase-frequency characteristics of photoelectric diodes have major influences on the design of high-speed receiving systems.