ABSTRACT
The history of electromagnetism saw the light with the early studies of Michael Faraday in 1821 and James Clerk Maxwell in 1865, who first theorized the existence of electric and magnetic waves. However, experimental evidence of Maxwell theories was found several years later thanks to the research carried out by David E. Hughes in 1879, although wrongly attributed to magnetic induction rather than electromagnetism; Thomas A. Edison, who obtained the very first wireless patent of the history in 1885; Heinrich Hertz, who first demonstrated the possibility to transmit and receive electromagnetic waves in 1887; and Guglielmo Marconi, who realized the first long-distance transmission and reception of electromagnetic waves covering more than 3500 km over the Atlantic Ocean in 1901. At that time, neither Marconi nor any of his predecessors could ever be aware of what such discoveries would have given beginning to. Wireless communications, as exchange of information over short or long distances in the form of acoustic waves, radio waves, or light (either visible or not), traveling in the ether, stimulated the scientific community to investigate this new frontier in all possible applications. But only in the 1960s, after prototyping the first silicon transistor in 1954 and when mass production of semiconductor transistors became practical, did all the exciting prospective become facts. Obviously first applications came from the military field, where wireless communications represented a big attractive, whereas for a long time civil applications of the ether transmission were limited to radio and television broadcasting. At that time, the bipolar junction transistor (BJT) was the most commonly used transistor. Even after the metal oxide semiconductor field-effect transistor (MOSFET) became available, the BJT remained the transistor of choice for many analog circuits because of its superior electrical properties and ease of manufacture.
