When an SIS mixer is partially saturated by broadband noise, it continues to exhibit a linear response to a small CW test signal, with the small-signal gain depending on the level of the saturating noise. This allows the CW test signal to be used as an indicator of the receiver gain in the presence of high-level noise. If not taken into account, gain compression can be a significant factor limiting the accuracy of high precision radio astronomy instruments.
View a pdf version of ALMA Memo #460.1.
View a pdf version of ALMA Memo #460.
Last modified: 2003-06-10