Wideband high-resolution versatile spectrometer proposed for FIRST-HIFI

We present a versatile digital autocorrelation spectrometer designed to suit the needs of HIFI, the sub-millimeter heterodyne instrument of the ESA's FIRST satellite. This spectrometer will offer a set of three observation modes with different `on-line resolution/total band-width' combinations (82 kHz/500 MHz, 163 kHz/1 GHz and 325 kHz/2 GHz). An original architecture based on mixed Gallium Arsenide and Silicon technologies, allowed us to realize a 1024 channel, low power consumption and high speed correlation module: 4 mW per channel at 550 MHz clock frequency. A prototype spectrometer has been developed. It includes a 2 X 250 MHz Image Rejection Mixer, a 500 MHz clock frequency analogue to digital converter, and two 1024 channel digital correlators. This model has been integrated and tested (in laboratory and on telescope). We expose these test results.