摘要 |
In a filtering apparatus, an analog filter filters a measured analog signal based on a predetermined filtering characteristic. An A/D converter converts, at constant time intervals, the filtered analog signal into a train of digital samples. A storage unit has a memory and stores, in the memory, the converted digital samples in the order from a first-converted digital sample in the train to a last-converted digital sample therein. A digital filtering unit has a second filtering characteristic substantially identical to the first filtering characteristic of the analog filter. The digital filtering unit reads out, from the memory, the digital samples in the order from the last-converted digital sample to the first-converted digital sample. The digital filtering unit filters the readout digital samples based on the second filtering characteristic in the order from the last-converted digital sample to the first-converted digital sample.
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