History of Radio

• The history of radio started with lots of different people but the most common people are Jagadish Chandra Bose, Guglielmo Marconi , Alexander Stepanvich Popov and Nikola Tesla.

• the late 19th century was the years were various scientist experimented with wireless communication. this means that various theoretical and experimental led to the development of radio and the communications system today.
• some early works were done on local effects and experiments of electromagnetic induction.
• the first radio transmission was done under radio telegraph system, which didn't have audio sound. the first radio station were AM and FM which was aired commercial, public and nonprofit varieties. 

Nikola Tesla

• In addition Nikola Tesla was the first to develop radio frequencies.
• in 1891 Nikola Tesla started the research on radio later on the years he published articles and gave lecture on the experiments with alternate currents of high potential and high frequency.
• in 1893 Nikola Tesla gave a public demonstration of wireless radio communication.
• after the demonstration Nikola Tesla work was publicized widely, this means that other scientists and inventors began to experiment with Nikola Tesla theory.

James Clerk Maxwell

• James Clerk Maxwell developed a set of equations that describes electromagnetic wave. 
• later on the years James Clerk Maxwell developed his theory by using other works of other scientists  form this James Maxwell invented the existence of electromagnetism.
• in 1873 James Clerk Maxwell described the theoretical basis of the propagation of electromagnetic waves in his pare to the Royal Society.

20th Century Developments

• 1954 Regency company introduced a pocket transistor radio (TR-1) which was powered by a 22.5v battery.
• in the 1960s VOR system was invented but it was wide hit with the aircraft navigation before VOR system aircraft navigation used AM radio stations for navigation.
• 1960 Sony company introduced the first transistorized radio, it was Small that it could fit in a pocket and it was powered by a small battery.
• on the twenty years radio technology has been improving more and more this because the technology system are getting more smaller by the minute.
• later on colour televisions and digital com for example in 1963 : colour television was introduced and the first radio satellite telstar was launched.
• the late 1960s were the years where digital telephone was invented to make the telephone system in to a digital format.
• the 1970s : the company LORAN became the hit radio navigation system. later the U.S. Navy started to experiment with satellite navigation.
• in 1987: the GPS constellation of satellite was introduced.
• the early 1990s century: amateur radio was researched and experimented on, this means that experimenters used the personal computers to get radio signals.
• in 1994 the U.S.A army and DARPA launched a big research on constructing software radio that could be used in flying but only changing the software.

21st Century Development

• in the 21st century Internet radio is the biggest invention of the audio industry. this means that the radio can be heard through a radio-style audio programming with Internet connections, no radio transmitters is used.
• digital audio broadcasting has became big because DAB has grown to relate to FM radio for other countries.
• most radio shows can be heard live in the Internet, in cars and other technologies means that radio has improved and became advanced in many ways for example for the early days of the 1870s century radio was being researched but in the 21st century radio is becoming smaller and smaller until we have radio on our hands.
  
  i have used wikipedia to find the information on history of radio
  http://en.wikipedia.org/wiki/History_of_radio