[2] Zohar Zisapel was born in Tel Aviv, one of three children of immigrant parents from Poland who owned and ran a shoe store on Herzl Street, then one of the city’s main arteries.[citation needed] Zisapel worked for the Electronic Research Department of the Ministry of Defense in Tel Aviv and rose to become its head.[5] In the mid-1970s, Yehuda Zisapel, Zohar's elder brother, founded a small private company that marketed data communications products.Operating from small, cramped quarters in the back of Bynet’s offices, Zohar oversaw the development of RAD’s first product, a miniature modem that would revolutionize the industry.This approach grew into the RAD Group, a family of independent companies that develop, manufacture, and market solutions for diverse segments of the networking and telecommunications industries.[16] Zisapel was the father of two children: a daughter, Klil, an accomplished artist and Hebrew writer whose books have been translated into German, Dutch and Chinese, and Michael, a physician.