Ian Poole - Basic Radio: Principles and Technology

The benefits of radio technology are an integral partof our everyday life. Over the past decades we have come to acceptradio, taking it for granted and not realizing how much it contributesto the running of modern society.

Radio performs many functions today, but the most obvious must bedomestic broadcasting. Most homes have a variety of radio sets, rangingfrom the relatively simple and cheap portable radios, through the moresophisticated car radios to the high fidelity systems. All of these setsoffer a high degree of performance which is the result of use anddevelopment over many years. Even so, the performance of radio sets isbeing improved and new facilities are being introduced all the time. Theintroduction of wideband FM represented a major improvement when it wasfirst introduced in the early 1950s. Stereo and RDS (Radio Data System)are two more which are in use today, and digital audio broadcasting hasstarted. This brings true CD quality to radio broadcasts as well asallowing data to be broadcast at the same time.

Cellular phones are another benefit which have been brought about bythe development of radio. They have enabled people to make phone callsor to be contacted even when they are away from home or the office.Their flexibility has meant that since their introduction in the UK in1984 there has been a phenomenal growth in this market. Phones areavailable very cheaply, and even the line rental and call charges arefalling as the number of operators increases. This means that a widevariety of people are able to use these phones. Initially they weremainly for business use. Now with the falling charges the number ofprivate users is increasing.

The introduction of the cellular phone systems has done much toadvance radio technology. Since their first introduction the sizes ofphones have fallen. The first portable sets required the use of largebatteries, whereas now the phones are truly hand-held and can beslipped into any pocket. Achieving this has required a large amount ofdevelopment. More areas of the phones have been integrated onto siliconchips. Now low power consumption, ultra high frequency, radio frequencyintegrated circuits are commonplace where a few years ago they were fewand far between.

Figure 1.1 Amodern World Band radio Courtesy of Sony UKLtd

Figure 1.2 Apocket sized cellular phone Courtesy of Sony UKLtd

Wireless communications have also enabled informationto be sent to and from all parts of the world more quickly. Now it ispossible to send and receive data, faxes, or voice from almost anywherein the world very easily. A good example of the way information can besent more swiftly is shown in the way news is received from around theworld almost instantaneously. This can be seen by comparing the newsreports of the Second World War, and the Gulf War of 1991. In the 1940sit took several hours for recorded reports from the front-linecorrespondents to reach the broadcasting stations. Film reports tookseveral days or weeks before they were seen as newsreels in the localcinemas. Now with satellite communications, modern video techniques andtelevision, things happen much faster. In the Gulf War the action wasseen by millions in their homes as it happened. Fortunately there aremany more less hostile examples of how radio has helped improve thestandards of modern life. Here radio has enabled many people to berescued by the emergency services far more efficiently than if therewere no radio present.