| 摘要 |
PROBLEM TO BE SOLVED: To provide a frequency measuring device and an inspection system that perform measurement with high speed/high resolution, even with a simple configuration. SOLUTION: The frequency measuring device 2 includes a frequency conversion part 10, a first filter 20, a mixer 30, a second filter 40, and a frequency measurement unit 50. The frequency conversion part converts a signal to be measured 5 into a signal of frequency having near a first frequency. The first filter has a band pass characteristics that the frequency near the first frequency is contained in a pass band region and is input an output signal 12 of the frequency conversion part. The mixer mixes an output signal 22 of the first filter and a standard clock signal 62 of a second frequency. The second filter has a band pass characteristics or a low pass characteristics which the frequency near the difference of the first frequency and the second frequency is included in the pass band region and the frequency near the sum of the first frequency and the second frequency is included in a rejection band region and is input the mixed output signal 32 of the mixer. The frequency measurement unit measures the frequency of the output signal 42 in the second filter. COPYRIGHT: (C)2010,JPO&INPIT |
