[4] In 1968, Phiilips moved to Bell Labs, where he worked down the hallway from Arno Penzias and Robert Wilson.
[5] Phillips set about doing so, and in 1973 he made the first Indium Antimonide (InSb) hot electron bolometer heterodyne receiver used for astronomical observations.
[9] By 1980, Phillips' InSb receiver could operate at 492 GHz, and with it mounted on the Kuiper Airborne Observatory, the 3P1—3P0 fine structure line of neutral atomic carbon was detected in the interstellar medium.
[11][5] In this same time period, Caltech was building a millimeter-wave interferometer at the Owens Valley Radio Observatory (OVRO), consisting of three (initially - later six) Leighton antennas.
[5] Eventually US and European efforts to produce such an instrument were merged, and Phillips became the co-Principal Investigator for the HIFI receiver on the Herschel Space Observatory.