This article details the history of electronics engineering. Chambers Twentieth Century Dictionary (1972) defines electronics as "The science and technology of the conduction of electricity in a vacuum, a gas, or a semiconductor, and devices based thereon". Electronics engineering as a profession sprang from technological improvements in the telegraph industry during the late 19th century and in the radio and telephone industries during the early 20th century. People gravitated to radio, attracted by the technical fascination it inspired, first in receiving and then in transmitting. Many who went into broadcasting in the 1920s had become "amateurs" in the period before World War I. The modern discipline of electronics engineering was to a large extent born out of telephone-, radio-, and television-equipment development and the large amount of electronic-systems development during World War II of radar, sonar, communication systems, and advanced munitions and weapon systems. In the interwar years, the subject was known as radio engineering. The word electronics began to be used in the 1940s In the late 1950s, the term electronics engineering started to emerge. Electronic laboratories (Bell Labs, for instance) created and subsidized by large corporations in the industries of radio, television, and telephone equipment, began churning out a series of electronic advances. The electronics industry was revolutionized by the inventions of the first transistor in 1948, the integrated circuit chip in 1959, and the silicon MOSFET (metal–oxide–semiconductor field-effect transistor) in 1959. In the UK, the subject of electronics engineering became distinct from electrical engineering as a university-degree subject around 1960. (Before this time, students of electronics and related subjects like radio and telecommunications had to enroll in the electrical engineering department of the university as no university had departments of electronics. Electrical engineering was the nearest subject with which electronics engineering could be aligned, although the similarities in subjects covered (except mathematics and electromagnetism) lasted only for the first year of three-year courses.) Electronics engineering (even before it acquired the name) facilitated the development of many technologies including wireless telegraphy, radio, television, radar, computers, and microprocessors.
Wireless telegraphy and radio
Some of the devices which would enable wireless telegraphy were invented before 1900. These include the spark-gap transmitter and the coherer with early demonstrations and published findings by David Edward Hughes (1880) and Heinrich Rudolf Hertz (1887 to 1890) and further additions to the field by Édouard Branly, Nikola Tesla, Oliver Lodge, Jagadish Chandra Bose, and Ferdinand Braun. In 1896, Guglielmo Marconi went on to develop the first practical and widely used radio wave based communication system. Millimetre wave communication was first investigated by Jagadish Chandra Bose during 1894–1896, when he reached an extremely high frequency of up to 60 GHz in his experiments. He also introduced the use of semiconductor junctions to detect radio waves, when he patented the radio crystal detector in 1901. In 1904, John Ambrose Fleming, the first professor of electrical Engineering at University College London, invented the first radio tube, the diode. Then, in 1906, Robert von Lieben and Lee De Forest independently developed the amplifier tube, called the triode. Electronics is often considered to have begun with the invention of the diode. Within 10 years, the device was used in radio transmitters and receivers as well as systems for long distance telephone calls. The invention of the triode amplifier, generator, and detector made audio communication by radio practical. (Reginald Fessenden's 1906 transmissions used an electro-mechanical alternator.) In 1912, Edwin H. Armstrong invented the regenerative feedback amplifier and oscillator; he also invented the superheterodyne radio receiver and could be considered the father of modern radio. The first known radio news program was broadcast 31 August 1920 by station 8MK, the unlicensed predecessor of WWJ (AM) in Detroit, Michigan. Regular wireless broadcasts for entertainment commenced in 1922 from the Marconi Research Centre at Writtle near Chelmsford, England. The station was known as 2MT and was followed by 2LO broadcasting from Strand, London. While some early radios used some type of amplification through electric current or battery, through the mid-1920s the most common type of receiver was the crystal set. In the 1920s, amplifying vacuum tubes revolutionized both radio receivers and transmitters. Vacuum tubes remained the preferred amplifying device for 40 years, until researchers working for William Shockley at Bell Labs invented the transistor in 1947. In the following years, transistors made small portable radios, or transistor radios, possible as well as allowing more powerful mainframe computers to be built. Transistors were smaller and required lower voltages than vacuum tubes to work. Before the invention of the integrated circuit in 1959, electronic circuits were constructed from discrete components that could be manipulated by hand. These non-integrated circuits consumed much space and power, were prone to failure and were limited in speed although they are still common in simple applications. By contrast, integrated circuits packed a large number — often millions — of tiny electrical components, mainly transistors, into a small chip around the size of a coin.
Television
In 1927, Philo Farnsworth made the first public demonstration of a purely electronic television. During the 1930s, several countries began broadcasting, and after World War II it spread to millions of receivers, eventually worldwide. Ever since then, electronics have been fully present in television devices. Modern televisions and video displays have evolved from bulky electron tube technology to use more compact devices, such as plasma and liquid-crystal displays. The trend is for even lower power devices such as the organic light-emitting diode displays, and it is most likely to replace the LCD and plasma technologies.
Radar and radio location
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