Patent ID: 8407268

Claim:
A power analyzer adapted for determining an optimum sampling frequency comprising: an analog/digital converter adapted for sampling a continuous time domain signal to obtain a digital sampling signal according to a predetermined sampling frequency and a predetermined number of sample points; a processor coupled to said analog/digital converter, and adapted for performing the following steps a) obtaining two reference sampling signals based upon the digital sampling signal obtained by said analog/digital converter, wherein one of the reference sampling signals is obtained using a higher sampling frequency that is higher than the predetermined sampling frequency used by said analog/digital converter, and the other one of the two reference sampling signals is obtained using a lower sampling frequency that is lower than the predetermined sampling frequency used by said analog/digital converter, b) transforming the digital sampling signal obtained by said analog/digital converter and the reference sampling signals obtained in step a) to frequency domain signals using Fast Fourier Transform, respectively, c) computing a sum-of-amplitudes for each of the three frequency domain signals obtained in step b), d) estimating a minimum sum-of-amplitudes value and a corresponding re-sampling frequency based upon the three sums-of-amplitudes computed in step c) and the corresponding sampling frequencies used by said analog/digital converter and in step a), e) obtaining a new reference sampling signal based upon the sampling signal obtained by said analog/digital converter using the re-sampling frequency, f) transforming the new reference sampling signal obtained in step e) to a frequency domain signal using Fast Fourier Transform, g) computing a sum-of-amplitudes for the frequency domain signal obtained in step f), h) re-estimating the minimum sum-of-amplitudes value and the corresponding re-sampling frequency with the sum-of-amplitudes obtained in step g) being used to replace one of the three sums-of-amplitudes that was used to estimate the previous minimum sum-of-amplitudes value and that has a largest variance with the sum-of-amplitudes obtained in step g), and with the re-sampling frequency used in step e) being used to replace one of the three sampling frequencies that was used to estimate the previous minimum sum-of-amplitudes value and that corresponds to said one of the three sums-of-amplitudes with the largest variance, and i) repeating steps e) to h) until respective changes in the re-estimated minimum sum-of-amplitudes value and the corresponding re-sampling frequency conform with a predetermined convergence standard, wherein the re-sampling frequency that conforms with the predetermined convergence standard is the optimum sampling frequency; and a display unit coupled to and controlled by said processor, and adapted for outputting an optimum frequency spectrum based upon the optimum sampling frequency obtained by said processor.