| 摘要 |
<p>PROBLEM TO BE SOLVED: To enhance the cost performance of an interleave A/D conversion-system waveform digitizer apparatus by a constitution wherein the output of a semiconductor device is digital-converted from an analog signal so as to be interleaved, a phase-error correction factor is inserted and a butterfly computing operation is performed. SOLUTION: A first A/D converter 31 and a second A/D converter 32 output even- number time-series data D0, D2,... and odd-number time-series data D1, D3,... which are sampled by respective sampling blocks at a sampling cycle 2Ts. An alignment part 40 outputs time-series data D0, D1, D2,..., at a cycle Ts, which are alignment- converted alternately from both data columns. A final-stage butterfly computing part 220 in an FFT processing part 50 calculates a first phase error factorα, a second phase error factorβand a third phase error factorβ' on the basis of a phase errorγby the deviation in terms of time between even-number-th input data and odd-number- th input data and on the basis of the sampling cycle Ts. The factorαis multiplied by the factorsβ,β' in a first FFT processing part 51, and the factorsβ,β' are multiplied by data sequences in a first FFT processing part 51 and the second FFE processing part 52. As a result, an FFT output which offsets an error due to the phase errorγis obtained.</p> |
