A lot of controversy surrounds the question of who really invented the radio. While there's a long list of names attached to the invention, most people assume that it was Guglielmo Marconi. However, there was a man named Nikola Tesla who came up with the fundamental design for the radio years before Marconi did.
On June 23, 1891, Tesla took out U.S. Patent 0454622 on an invention known as a Tesla coil. The coil was a disruptive coil that would be used in spark-gap radio transmitters, which were devices that generated radio frequency electromagnetic waves. These waves would be what allowed radio communication all the way up to the 1920s.
In 1893, Tesla carried out his first experiments with high frequency electric currents. He chose to experiment with magnetic receivers while others were experimenting with coherer receivers at the time, including Guglielmo Marconi. He went on to hold a demonstration before both the Franklin Institute in Philadelphia and the National Electric Light Society in St. Louis where he used a device for radio transmission or reception. Tesla described his idea for a wireless network and his description contained all the elements that would later be incorporated into the first radio. This was a full eleven years before Marconi was awarded his first wireless patent.
Guglielmo Marconi, meanwhile, had begun conducting experiments at his home in Pontecchio, Italy. His aim was to figure out a way to send telegraph messages without needing to use wires. He finally managed to succeed in sending a message one and a half miles between his window and the end of his garden.
Marconi headed to England in 1896, where he transmitted a Morse code message over a 2-mile distance. And on July 2, 1897, he was awarded British Patent GB12039, a patent for "improvements in transmitting electrical impulses and signals and in apparatus there-for." It was originally considered to be the first patent in radio telecommunication.
However, Tesla had completed a similar experiment that same year. In the summer of 1897, he decided to test his wireless telegraphy system by placing a receiver on a boat floating in the Hudson River. The receiver picked up signals at a distance of 25 miles. Tesla filed for patents but it wasn't until March 20, 1900, that he was awarded Patent 0645576 for the "system of electrical transmission energy." Tesla then began planning the Wardenclyffe Tower facility, a wireless power transmission facility. However, Marconi succeeded in being the first to send and receive a message over the Atlantic Ocean.
In 1904, the U.S. patent office gave Marconi a patent for the invention of the radio. Marconi would go on to win a Nobel Prize for his work seven years later. Even though he was close to flat broke, Tesla sued the Marconi Company for infringement in 1915. The court ruled that Marconi's patents contained nothing new that had not already been published by Tesla himself. Sadly, Tesla would not live to see the case resolved. On January 8, 1943, Tesla died of heart failure in New York. Later that same year, the US Supreme court upheld Tesla's 1900 patent, establishing him as the true inventor of the radio.