Karl D. Stephan received the B. S. in Engineering from the California Institute of Technology in 1976. Following a year of graduate study at Cornell, he received the Master of Engineering degree in 1977 and was employed by Motorola, Inc. and Scientific-Atlanta as an RF development engineer.
He then entered the University of Texas at Austin's graduate program and received the Ph. D. in electrical engineering in 1983. He taught at the University of Massachusetts Amherst from 1983 to 1999, when he received an NSF Science and Technology Studies Fellowship in the history of technology.
He spent the 1999-2000 academic year at the University of Texas at Austin, and in 2000 accepted a position as Associate Professor in the Department of Technology at Texas State University, San Marcos, Texas. In 2009, he was promoted to full professor and moved to the Ingram School of Engineering. He has also received an appointment as Adjunct Associate Research Professor at the University of Texas at Austin's Department of Electrical and Computer Engineering.