| 摘要 |
PROBLEM TO BE SOLVED: To speedily obtain a wide-band spectrum identical to a sweep type frequency analyzer at one measurement in wide-band spectrum measurement by FFT (fast-fourier transformation) processing, without combining a plurality of results. SOLUTION: A local oscillator emits a sweep signal, of which the frequency increases or decreases in a uniform rate at a certain time intervals in place of the local oscillation signal by a fixed frequency. An FFT calculating circuit is constituted to cancel the sweep signal, and for extracting only the frequency components in a base-band signal, and it preliminarily operates, by multiplying the product of a sweep compensation signal and a window function to the base-band signal and executes FFT processing. COPYRIGHT: (C)2005,JPO&NCIPI
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