Sandy Weinreb has spent most of his career perfecting the design of radio astronomy receivers, small critical components of radio telescopes that amplify and digitize feeble radio waves from the cosmos. Weinreb joined Caltech in 1999 and is currently an emeritus research associate in astronomy at the Institute. He spearheaded development of uncooled low-noise amplifiers that will debut on Caltech's Deep Synoptic Array (DSA) telescope, an array of thousands of dishes to be built in the Nevada desert over the next couple years.

Weinreb received his PhD degree in electrical engineering from the Massachusetts Institute of Technology in 1963. While he was still a graduate student at MIT, he developed the world's first digital autocorrelation spectrometer which he then used to place a new upper limit to the Galactic deuterium to hydrogen ratio. With Al Barrett, Lit Meeks, and J. C. Henry; he detected the OH molecule, which was the first radio observation of an interstellar molecule. His autocorrelation spectrometer technique is now in use at virtually every major radio observatory throughout the world and has been crucial in the subsequent explosive growth of interstellar molecular spectroscopy. 

In 1965 Weinreb went to NRAO where he became Head of the Electronics Division and later Assistant Director. During his 23 years at NRAO, he pioneered the use of low noise cryogenically cooled solid state amplifiers in radio astronomy. He was the architect for the electronic systems design for the NRAO Very Large Array in New Mexico and led the group which developed the novel front ends and the data transmission, acquisition, and monitor and control systems for the VLA.

Subsequently he worked at first at Lockheed Martin Laboratories and then at the University of Massachusetts where he developed MMIC amplifiers and other millimeter wave devices. He has also been a Visiting Professor at the University of Virginia. He held the position of Senior Faculty Associate at Caltech where he continued his work on MMIC devices. He has been active in developing wideband feeds and front ends as well as investigating cost effective designs for modest size antennas, all of which have been important for the next generation of radio telescopes.

In addition he has worked with the Goldstone Apple Valley Radio Telescope (GAVRT) program to develop a 34 m radio telescope at Goldstone for use with schools around the globe.