The Father of Radio: A Brief Chronology of the Origin and Development of Wireless Communications Magdalena Salazar-Palma1, Alejandro Garcia-Lamperez1, Tapan K Sarkar, and Dipak L. Sengupta3 1Departmen t of Signal Theory & Communications Universidad Carlos 1 11 de Madrid Avenida de la Universidad, 30, 28911 Legan es, Madrid, Spain E-mail: salazar@tsc.uc3m.es . alamparez@tsc.uc3m.es 2Departmen t of Electrical Eng ineering and Computer Sc ience Syracuse University Syracuse, New York 1 3244-1 240, USA E-mail: tksarkar@syr.edu http://Ics.syr.edu/facul ty/sarkar/ 3Department of Electrical Eng ineer ing and Computer Science University of Michigan, Ann Arbor 1 301 Seal Avenue, Ann Arbor, MI 481 09-21 22, U SA E-mail: sengupdl@eecs.um ich.edu Abstract This paper presents a chronology of the origin and development of wireless (or rad io) commun ications. It fol lows the following pattern. It gives credit to some of the scientists who provided the ini tial observat ions and understanding of electric and magnetic phenomena. I t then mentions the experiments and inven tions carried ou t toward the evolu tion of scientif ic and eng ineering models. F inally, it focuses on the implementation of practical wireless systems. The chronology leads us to conclude that the invention and developmen t of wireless/rad io systems can neither be credited to one individual nor to one specif ic country. The chronology strongly ind icates an overlapp ing of human thinking in time in many countries. This compelled us to not make a defini tive choice of an individual (or coun try) for the well-deserved credit. We leave i t up to the reader to make her or his own choice! 1. Introduction T he term "wireless " indicates communication without the use of wires. f course, such a term maybe applied to visual signaling systems, or to mechanical-optical systems such as those invented by the French engineer Claude Chappe, with the help of the French watchmaker, Abraham-Louis Brguet. Here, the word wireless refers to communication systems that involve electromagnetic signals. Various mechanisms were tried for such purposes: electrostatic coupling, conduction, magnetic induction, and electrmagnetic radiation or waves. The frst three, while indeed wireless, were extremely limited in the distance they were capable of covering. The breakthrough in wireless communications was the successful use of the fourth mechanism, which allowed long-distance transmission. The term radio was coined as a short name for electromagnetic radiation. Hence, it is possible to speak of some wireless systems as not being radio systems. However, because all the other types of wireless mechanisms were abandoned, nowadays the word "wireless " is synonymous with "radio. " Because the earliest radio communications used Morse's code for transmitting information, i.e., they were telegraph systems, I Antennas and Propagation Magaine, Vol. 53, No. 6, December 201 1 ISSN 1045-9243/2011/$26 ©2011 IEEE 83