| 摘要 |
<p>In accordance with the present invention, a pulse-based impedance measurement instrument (10) is provided. A pulse generator (52) repetitively generates a stimulus pulse to a device under test (DUT) (50). A digitizer circuit (61), consisting of a sample-and-hold circuit (54), an analog to digital converter (56), and acquisition memory (58), repetitively samples the response voltage across the DUT to create a time record of the voltage as a function of time during a pulse response measurement. Each time record is operated on by a Fast Fourier Transform (FFT) which converts the voltage versus time information into voltage versus frequency information in a manner well known in the art. By measuring a set of calibration resistors with known resistance values to generate a set of complex calibration constants, the impedance measurement instrument provides measurements of complex impedance and return loss versus frequency of a DUT. <IMAGE></p> |
