2SB mixer in radio astronomy? In literature about the instrumentation of radio astronomy, I frequently come across a type of mixer described as "2SB".  I'm familiar with single-sideband (SSB) and double-sideband (DSB) mixers, but I have never studied a 2SB mixer.

What is a 2SB mixer and how does it compare to a DSB mixer?  Ideally, I would also like to know of formal references that directly address the topic for further reading.
2SB is Dual Sideband, as opposed to DSB - Double Sideband. Here are a couple of papers you might find relevant and interesting:
a 2SB upgrade replacing a DSB
a paper that mentions the advantages of 2SB over DSB
Answers to What is the functional difference between DSB and 2SB mixers, and why exactly would 2SB be better for radio astronomy? in Signal Processing SE go into further detail.