John Battiscombe "J. B." Gunn (13 May 1928 – 2 December 2008), known as Ian or Iain, was a British physicist, who spent most of his career in the United States. He discovered the Gunn effect, which led to the invention of the Gunn diode, the first inexpensive source of microwave power that did not require vacuum tubes. He was born John Battiscombe Gunn, but only used that name in legal documents. Early life J. B. Gunn was born in 1928 in Cairo, Egypt, to Battiscombe "Jack" Gunn, a leading Egyptologist, and Lillian Florence (Meena) Meacham Hughes Gunn, who studied psychoanalytic technique with Sigmund Freud. In 1931 the family moved to Glen Riddle, Pennsylvania, while Jack was Curator of the Egyptian Section of the museum at the University of Pennsylvania in Philadelphia. As a young boy he already showed an interest in electronics. As his older half brother Pat (Spike) Hughes, wrote of a visit to Glen Riddle in 1933: "...at 4 years and a few months, Iain was already passionately interested in seeing how things worked, and showed a typical lack of concern for what came out of a loudspeaker, so long as he could make out why it came out at all. Thus at Iain's bedtime every night the Glen Riddle radio set had to be collected up and put together again – mainly for my benefit, for I suddenly felt myself cut off from my New York roots unless I could hear my favourite radio stations." The house at Glen Riddle was later owned by Ken Iverson, an IBM colleague and one of the inventors of APL. The Gunn family returned to England in 1934 when Jack was appointed Professor of Egyptology at the University of Oxford. It was at this point that the younger Gunn rejected the name "John". From then on, he was known personally as "Ian" or "Iain" (the Scottish form of "John"), given to him by his aunt, the Scottish nationalist Wendy Wood. He was known professionally as "J.B. Gunn". Ian was educated in England, with the exception of two years spent at Solebury School, Pennsylvania as a wartime evacuee. He was an undergraduate at Trinity College, Cambridge from 1945 to 1948. Official records show that Gunn studied Natural Sciences prelim Class II in 1946, Natural Sciences tripos Class III in 1947, Mechanical Science Class II in 1948 (in the terminology Cambridge used