Dr. Stephen A. Buckingham, 74, a retired physicist at The Johns Hopkins University Applied Physics Laboratory, which he helped establish in 1942, died Sunday at Holy Cross Hospital in Silver Spring of complications following a stroke.

During World War II, Dr. Buckingham worked on a number of technological developments at the laboratory, including the radio proximity (VT) fuze, which played a key role in defeating the German V-1 self-propelled bomb, and the Mark 57 antiaircraft gun director.

He was a member of the laboratory's research and development team responsible for development of the world's first supersonic ramjet engine, called the "flying stovepipe," also developed during the war. These pioneer air-breathing engines were prototypes of the engine that later powered the Navy's TALOS guided missile, only recently retired.

Following the war, Dr. Buckingham served as liaison engineer between the laboratory and the British Ministry of Supply. His work in recent years, before his retirement in 1970, on the development of navigation and research spacecraft is credited with making the Navy's Transit Satellite Navigation System "highly reliable." He also is credited with helping develop a program of exchange of technological information between industry and government.

Dr. Buckingham was a native Washingtonian. He graduated from the Sidwell Friends School and earned both a bachelor's degree and a master's degree in physics from Harvard University, where he was a physics instructor in the early 1930s.

Before joining the Hopkins Laboratory, Dr. Buckingham worked in industrial physics, specializing in paper making, the phonographic reproduction of sound and carrier telephony.

He was a University Fellow and a Whiting Fellow at Harvard University and a member of the American Physical Society, the Institute of Radio Engineers, the Institute of Electronics and Electronics Engineering and the Philosophical Society of Washington. He lived in Silver Spring.

Survivors include his wife, Margaret, of Silver Spring; a son, Anthony, of Greenbelt, and a sister, Katherine Hunt of La Jolla, Calif.