Erwin F. Belohoubek began working for RCA in the Electron Tube Division in Harrison, New Jersey in 1956. Along with the rest of the Microwave Advanced Development Group, he transferred to the David Sarnoff Research Center in Princeton in December 1956. In 1969, he was promoted to Group Head of Microwaves Circuits Technology Research. Belohoubek’s work focused on microwave technology, particularly on the use of microwaves in solid state amplifiers and in tubes.

Belohoubek’s research in the 1970s included the research safety vehicle (RSV), also known as the minicar. Minicars were small passenger vehicles outfitted with microwave technology that improved driving safety, such as assisted braking, cruise control, and automatic transmissions – all of which are now standard on vehicles. In the 1980s Belohoubek's research included the MARC-80 system, an RCA concept for a low-altitude air defense system developed from advanced mission studies for the U.S. Army. Belohoubek was issued five patents and wrote numerous scholarly articles. He received two RCA Outstanding Achievement Awards and was elected as a Fellow of IEEE in 1975.