SPECTRAL WINDOW OF THE ACOUSTOOPTIC FOLDED SPECTRUM ANALYZER

I derive here the spectral window of the acousto-optic folded spectrum analyzer proposed by [K. Wagner and D. Psaltis, Proc. Soc. Photo-Opt. Instrum. Eng. 564,209-223(1985)]. This window function turns out to b e quite informative. It clarifies important characteristics that disti nguish this system from the more conventional digital spectrum analyze rs, and it clarifies the relationships between various system design p arameters and helps guide their selection. The spectral window of one specific implementation of a finer-resolution version of this analyzer (the super-fine-resolution variant suggested in the above reference) is also determined. Analysis shows that for certain narrow-frequency r anges this window has two main lobes separated by a large number of su per-fine frequency-resolution bins. This characteristic makes it unacc eptable in many applications.