SWAS has a 55 x 71 cm elliptical off-axis Cassegrain telescope with a beam width of 4 arcminutes at its operating frequencies.
The submillimeter radiometers are a pair of passively cooled subharmonic Schottky diode receivers, with receiver noise figures of 2500-3000 K.
The outputs of the two SWAS receivers are combined to form a final intermediate frequency, which extends from 1.4 to 2.8 GHz. An acousto-optical spectrometer (AOS) (provided by the University of Cologne) records these spectra (taken every 2 seconds by the spacecraft) which are dispersed into 1400 1 MHz channels by the spectrometer.
