Radio has been a part of everyday life for almost 100 years. Though at first, they were only used to communicate for professional purposes, such as in military operations, their usage was quickly proliferated and by the early 1900’s, many if not most people had a radio in their home.
But what is radio? At a fundamental level, it can be understood as the transmission of waves which carry information. Though these pages will focus on radio used for broadcasting, there are in fact many other usage of radio waves such as navigation for boats and planes and also in certain medical technologies. The etymology of the word radio comes from the Latin word ‘radius’. In Latin, the term means ‘spokes of a wheel’. It was given the name radio when Alexander Bell, who invented the telephone used the term for an early prototype of a phone that resembled the spoke of a wheel. Though the invention did not take off, the name was to become popular in the modern lexicon.
For radio to work there needs to be a transmitter and a receiver. In broadcast terms, the transmitter will often be the source of the production, normally a radio studio, and the receiver is found on the individual radio device that is being listened to. Though radio broadcast on the internet has somewhat fractured this traditional understanding.
Though in broadcast terms radio transmission is one-way, two-way transmission is also widely used in radio communications, most notably in aircraft where the pilot can communicate with air traffic control. Though radio transmissions were traditionally analog, they are often broadcasted digitally as well. In traditional analog broadcasting, there are two wave types which are AM and FM but we will look into this in more detail later. Before the invention of the internet, pirate radio was also popular in the Unites States and Europe. Now one can freely broadcast on the internet and hence there is little use for private radio.