A very fast FFT spectrum analyzer for radio astronomy

A wide-band FFT spectrum analyzer, called FX, is in operation at the Nobeyama Radio Observatory for spectroscopy of radio waves from the molecules in the gas clouds which are the cradles of stars. It processes input of six 320MHz bandwidth data streams into the output of fifteen cross-power spectrums of 1024 frequency channels each. This processing speed is 10⁵times as high as usual computers. Its highly parallel pipeline architecture made it possible to achieve the above speed. The FX is made up of about 4500 LSI chips of CMOS gate arrays. They are designed using CAD and have 3900 or 2000 gates/chip, operate at 10 MHz clock rate, and consume 100 mW/chip or less. The SNR (signal-to-noise ratio) is better than 10 dB, which is adequate to the astronomical uses.