A long description of the company is found on "Raytheon Company: History," Raytheon, http://en.wikipedia.org/wiki/Raytheon (accessed 06/22/2015)
See also: "Raytheon Company History," Funding Universe, http://www.fundinguniverse.com/company-histories/Raytheon-Company-Company-History.html (accessed 06/22/2015)
For a history of Raytheon's role in the development of Radar, see: "IN SYNC with the UNIVERSE: Raytheon's Journey into the World of Radar", in Technology Today (Raytheon's magazine), Vol. 1, Issue 3, (Summer 2002), pp10-13. Available online via Internet Archive Wayback machine, http://web.archive.org/web/20120904222256/http://www.raytheon.com/technology_today/archive/2002_Issue3.pdf(accessed 06/22/2015)