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Radio

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Radio is the technology of communicating using radio waves.[1][2][3] Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates oscillating electrical energy, often characterized as a wave. They can be received by other antennas connected to a radio receiver, this is the fundamental principle of radio communication. In addition to communication, radio is used for radar, radio navigation, remote control, remote sensing, and other applications.

In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking, and satellite communication, among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave by varying some aspect of the wave) in the transmitter. In radar, used to locate and track objects like aircraft, ships, spacecraft and missiles, a beam of radio waves emitted by a radar transmitter reflects off the target object, and the reflected waves reveal the object's location to a receiver that is typically colocated with the transmitter. In radio navigation systems such as GPS and VOR, a mobile navigation instrument receives radio signals from multiple navigational radio beacons whose position is known, and by precisely measuring the arrival time of the radio waves the receiver can calculate its position on Earth. In wireless radio remote control devices like drones, garage door openers, and keyless entry systems, radio signals transmitted from a controller device control the actions of a remote device.

The emission of radio waves is regulated by law, coordinated by the International Telecommunication Union (ITU), which allocates frequency bands in the radio spectrum for various uses.

History[]

Early radio[]

Electromagnetic waves were predicted by James Clerk Maxwell in his 1873 theory of electromagnetism, now called Maxwell's equations, who proposed that a coupled oscillating electric field and magnetic field could travel through space as a wave, and proposed that light consisted of electromagnetic waves of short wavelength. On 11 November 1886, German physicist Heinrich Hertz, attempting to confirm Maxwell's theory, first observed radio waves he generated using a primitive spark-gap transmitter.[4] Experiments by Hertz and physicists Jagadish Chandra Bose, Oliver Lodge, Lord Rayleigh, and Augusto Righi, among others, showed that radio waves like light demonstrated reflection, refraction, diffraction, polarization, standing waves, and traveled at the same speed as light, confirming that both light and radio waves were electromagnetic waves, differing only in frequency.[5]

Bengali Indian physicist Jagadish Chandra Bose ignited gunpowder and rang a bell at a distance, using millimeter-range-wavelength microwaves, in a November 1894 public demonstration at the Town Hall of Kolkata, India. Bose wrote in a Bengali essay, "Adrisya Alok" ("Invisible Light"), "The invisible light can easily pass through brick walls, buildings etc. Therefore, messages can be transmitted by means of it without the mediation of wires." Bose's first scientific paper, "On polarisation of electric rays by double-refracting crystals" was communicated to the Asiatic Society of Bengal in May 1895.

Following that, Bose produced a series of articles in English, one after another. His second paper was communicated to the Royal Society of London by Lord Rayleigh in October 1895. In December 1895, the London journal The Electrician (Vol. 36) published Bose's paper, "On a new electro-polariscope". At that time, the word 'coherer', coined by Lodge, was used in the English-speaking world to mean Hertzian wave receivers or detectors. The Electrician (December 1895) readily commented on Bose's coherer. The Englishman (18 January 1896) quoted from The Electrician and commented as follows: "Should Professor Bose succeed in perfecting and patenting his ‘Coherer’, we may in time see the whole system of coast lighting throughout the navigable world revolutionised by an Indian Bengali scientist working single handed[ly] in our Presidency College Laboratory." Bose planned to "perfect his coherer", but never thought of patenting it.

In 1895, Guglielmo Marconi developed a radio communication system, using a spark-gap transmitter to send Morse code over long distances. By December 1901, he had transmitted across the Atlantic Ocean.[4][6][7][8] Marconi and Karl Ferdinand Braun shared the 1909 Nobel Prize in Physics "for their contributions to the development of wireless telegraphy".[9]

During radio's first two decades, called the radiotelegraphy era, the primitive radio transmitters could only transmit pulses of radio waves, not the continuous waves which were needed for audio modulation, so radio was used for person-to-person commercial, diplomatic and military text messaging. Starting around 1908 industrial countries built worldwide networks of powerful transoceanic transmitters to exchange telegram traffic between continents and communicate with their colonies and naval fleets. During World War I the development of continuous wave radio transmitters, rectifying electrolytic, and crystal radio receiver detectors enabled amplitude modulation (AM) radiotelephony to be achieved by Reginald Fessenden and others, allowing audio to be transmitted. On 2 November 1920, the first commercial radio broadcast was transmitted by Westinghouse Electric and Manufacturing Company in Pittsburgh, under the call sign KDKA featuring live coverage of the Harding-Cox presidential election.[10]

By 1963, color television was being broadcast commercially (though not all broadcasts or programs were in color), and the first (radio) communication satellite, Telstar, was launched. In the 1970s, LORAN became the premier radio navigation system. Soon, the U.S. Navy experimented with satellite navigation, culminating in the launch of the Global Positioning System (GPS) constellation in 1987.

Transistor radio[]

Following development of transistor technology, bipolar junction transistors led to the development of the transistor radio. In 1955, the newly formed Sony company introduced the first popular transistorized radio, the TR-55.[11] It was small enough to fit in a vest pocket, powered by a small battery. It was durable, because it had no vacuum tubes to burn out. In 1957, Sony introduced the TR-63, the first mass-produced transistor radio, leading to the mass-market penetration of transistor radios.[12] It was small enough to fit in a vest pocket, and able to be powered by a small battery. It was durable, because there were no tubes to burn out. Over the next 20 years, transistors replaced tubes almost completely except for high-power transmitters.

Following development of transistor technology, bipolar junction transistors led to the development of the transistor radio. In 1954, Regency introduced a pocket transistor radio, the TR-1, powered by a "standard 22.5V Battery". In 1955, the newly formed Sony company introduced its first transistorized radio, the TR-55.[11] In 1957, Sony introduced the TR-63, the first mass-produced transistor radio, leading to the mass-market penetration of transistor radios.[12]

The metal–oxide–semiconductor field-effect transistor (MOSFET), also known as MOS transistor, was invented by Mohamed Atalla and Dawon Kahng in 1959.[13][14][15] By the mid-1960s, the Radio Corporation of America (RCA) were using metal–oxide–semiconductor field-effect transistors (MOSFETs) in their consumer products, including FM radio, television and amplifiers.[16] Metal–oxide–semiconductor (MOS) large-scale integration (LSI) provided a practical and economic solution for radio technology, and was used in mobile radio systems by the early 1970s.[17]

Color television[]

Digital radio[]

In the 1970s, the U.S. long-distance telephone network began to transition towards a digital telephone network, employing digital radios for many of its links. The transition towards digital telecommunication networks was enabled by mixed-signal MOS integrated circuit chips using switched-capacitor (SC) and pulse-code modulation (PCM) technologies.[19][20] In the late 1980s, Asad Ali Abidi at UCLA developed RF CMOS (radio-frequency CMOS),[21] a radio transceiver system on a mixed-signal MOS IC chip,[22] which enabled the introduction of digital signal processing in wireless communications.[23]

In 1990, discrete cosine transform (DCT) video coding standards enabled digital television (DTV) transmission in both standard-definition TV (SDTV) and high-definition TV (HDTV) formats.[24] In the early 1990s, amateur radio experimenters began to use personal computers with audio cards to process radio signals.

In the 1990s, the wireless revolution began,[25][26][27] with the advent of digital wireless networks.[28] It began with the introduction of digital cellular mobile networks, enabled by LDMOS (power MOSFET) RF power amplifiers and CMOS RF circuits.[29][30][21] In 1994, the U.S. Army and DARPA launched an aggressive, successful project to construct a software-defined radio that can be programmed to be virtually any radio by changing its software program.

Digital transmissions began to be applied to commercial broadcasting in the late 1990s. In 1995, Digital Audio Broadcasting (DAB), a digital radio standard, launched in Europe. ISDB-S, a Japanese digital television standard, was launched in 1996, and was later followed by the ISDB-T digital radio standard.

Digital era[]

  • 1970s: The US long-distance telephone network began to transition towards a digital telephone network, employing digital radios for many of its links, enabled by mixed-signal MOS integrated circuit (MOS IC) chips using switched-capacitor (SC) and pulse-code modulation (PCM) technologies.[19][20]
  • 1980s: Asad Ali Abidi at UCLA developed RF CMOS (radio-frequency CMOS),[21] a radio transceiver system on a mixed-signal MOS IC chip,[22] which enabled the introduction of digital signal processing in wireless communications.[23]
  • 1990: Discrete cosine transform (DCT) video coding standards enabled digital television (DTV) transmission in both standard-definition TV (SDTV) and high-definition TV (HDTV) formats.[24]
  • Early 1990s: Amateur radio experimenters began to use personal computers with audio cards to process radio signals.
  • Early 1990s: Digital cellular mobile networks introduced, enabled by LDMOS (power MOSFET) RF power amplifiers and CMOS RF circuits.[29][30][21]
  • 1990s: Wireless revolution began,[25][26][27] with the advent of digital wireless networks.[28]
  • 1994: The US Army and DARPA launched an aggressive successful project to construct a software radio that could become a different radio on the fly by changing software.
  • Late 1990s: Digital transmissions began to be applied to commercial broadcasting.
  • 1995: Digital Audio Broadcasting (DAB), a digital radio standard, launched in Europe. DAB+ was later launched in 2007.
  • 1996: ISDB-S, a digital television standard, launched in Japan. Its digital radio counterpart, ISDB-T, was later launched in 2003.
  • 1997: High-Efficiency Advanced Audio Coding (AAC+), a modified discrete cosine transform (MDCT) audio codec, was introduced. It later became the audio coding format for digital radio standards such as DAB+[31] and HD Radio.[32]
  • 2015: The first commercial all-digital radio transmitter, called Pizzicato, was introduced.[33]

Mobile radio[]

Main article: Mobile phone

The development of metal–oxide–semiconductor (MOS) large-scale integration (LSI) technology, information theory and cellular networking led to the development of affordable mobile communications.[23]

See also[]

  • Electromagnetic radiation and health
  • Internet radio
  • Outline of radio
  • Radio quiet zone

References[]

  1. ↑ "Radio". Oxford Living Dictionaries. Oxford University Press. 2019. Archived from the original on 24 March 2019. Retrieved 26 February 2019.
  2. ↑ "Definition of radio". Encyclopedia. PCMagazine website, Ziff-Davis. 2018. Retrieved 26 February 2019.
  3. ↑ Ellingson, Steven W. (2016). Radio Systems Engineering. Cambridge University Press. pp. 1–4. ISBN 978-1316785164.
  4. ↑ 4.0 4.1 "125 Years Discovery of Electromagnetic Waves". Karlsruhe Institute of Technology. 16 May 2022. Archived from the original on 14 July 2022. Retrieved 14 July 2022.
  5. ↑ Sungook Hong (2001), Wireless: From Marconi's Black-box to the Audion, MIT Press, pp. 5–10
  6. ↑ Bondyopadhyay, Prebir K. (1995) "Guglielmo Marconi – The father of long distance radio communication – An engineer's tribute", 25th European Microwave Conference: Volume 2, pp. 879–85
  7. ↑ "1890s – 1930s: Radio". Elon University. Archived from the original on 8 June 2022. Retrieved 14 July 2022.
  8. ↑ Belrose, John S. (5–7 September 1995). "Radio's First Message -- Fessenden and Marconi". Institute of Electrical and Electronics Engineers. Retrieved 6 November 2022.
  9. ↑ "The Nobel Prize in Physics 1909". NobelPrize.org. 2023. Archived from the original on 31 July 2023. Retrieved 31 July 2023.
  10. ↑ "History of Commercial Radio". Federal Communications Commission. 23 October 2020. Archived from the original on 1 January 2022. Retrieved 14 July 2022.
  11. ↑ 11.0 11.1 "Transistor Radios". ScienCentral (pbs.org). 1999. Retrieved 2018-02-03.
  12. ↑ 12.0 12.1 Skrabec, Quentin R., Jr. (2012). The 100 Most Significant Events in American Business: An Encyclopedia. ABC-CLIO. pp. 195–7. ISBN 0313398631.{{cite book}}: CS1 maint: multiple names: authors list (link)
  13. ↑ "Martin (John) M. Atalla". National Inventors Hall of Fame. 2009. Retrieved 21 June 2013.
  14. ↑ "Dawon Kahng". National Inventors Hall of Fame. Retrieved 27 June 2019.
  15. ↑ Bassett, Ross Knox (2007). To the Digital Age: Research Labs, Start-up Companies, and the Rise of MOS Technology. Johns Hopkins University Press. p. 22. ISBN 978-0801886393.
  16. ↑ 16.0 16.1 Harrison, Linden T. (2005). Current Sources and Voltage References: A Design Reference for Electronics Engineers. Elsevier. p. 185. ISBN 978-0-08-045555-6.
  17. ↑ Zeidler, G.; Becker, D. (1974). "MOS LSI Custom Circuits Offer New Prospects for Communications Equipment Design". Electrical Communication. Western Electric Company. 49–50: 88–92. In many fields of communications equipment design, MOS LSI custom built circuits provide the only practical and economic solution. (...) A complete list of all applications is beyond the scope of this paper since new MOS developments are constantly being initiated in the various technical areas. Typical examples of completed and present MOS developments are:
    — crosspoints
    — multiplexers
    — modems
    — mobile radios
  18. ↑ Amos, S. W.; James, Mike (2013). Principles of Transistor Circuits: Introduction to the Design of Amplifiers, Receivers and Digital Circuits. Elsevier. p. 332. ISBN 9781483293905.
  19. ↑ 19.0 19.1 Allstot, David J. (2016). "Switched Capacitor Filters". In Maloberti, Franco; Davies, Anthony C. (eds.). A Short History of Circuits and Systems: From Green, Mobile, Pervasive Networking to Big Data Computing (PDF). IEEE Circuits and Systems Society. pp. 105–110. ISBN 9788793609860.
  20. ↑ 20.0 20.1 Floyd, Michael D.; Hillman, Garth D. (8 October 2018) [1st pub. 2000]. "Pulse-Code Modulation Codec-Filters". The Communications Handbook (2nd ed.). CRC Press. pp. 26–1, 26–2, 26–3.
  21. ↑ 21.0 21.1 21.2 21.3 O'Neill, A. (2008). "Asad Abidi Recognized for Work in RF-CMOS". IEEE Solid-State Circuits Society Newsletter. 13 (1): 57–58. doi:10.1109/N-SSC.2008.4785694. ISSN 1098-4232.
  22. ↑ 22.0 22.1 Lee, Thomas H. (2004). The Design of CMOS Radio-Frequency Integrated Circuits, 2nd Ed. UK: Cambridge University Press. pp. 1–8. ISBN 978-0521835398.
  23. ↑ 23.0 23.1 23.2 Srivastava, Viranjay M.; Singh, Ghanshyam (2013). MOSFET Technologies for Double-Pole Four-Throw Radio-Frequency Switch. Springer Science & Business Media. p. 1. ISBN 9783319011653.
  24. ↑ 24.0 24.1 Barbero, M.; Hofmann, H.; Wells, N. D. (14 November 1991). "DCT source coding and current implementations for HDTV". EBU Technical Review. European Broadcasting Union (251): 22–33. Retrieved 4 November 2019.
  25. ↑ 25.0 25.1 Golio, Mike; Golio, Janet (2018). RF and Microwave Passive and Active Technologies. CRC Press. pp. ix, I-1, 18–2. ISBN 9781420006728.
  26. ↑ 26.0 26.1 Rappaport, T. S. (November 1991). "The wireless revolution". IEEE Communications Magazine. 29 (11): 52–71. doi:10.1109/35.109666.
  27. ↑ 27.0 27.1 "The wireless revolution". The Economist. January 21, 1999. https://www.economist.com/leaders/1999/01/21/the-wireless-revolution. Retrieved 12 September 2019. 
  28. ↑ 28.0 28.1 Baliga, B. Jayant (2005). Silicon RF Power MOSFETS. World Scientific. ISBN 9789812561213.
  29. ↑ 29.0 29.1 Baliga, B. Jayant (2005). Silicon RF Power MOSFETS. World Scientific. ISBN 9789812561213.
  30. ↑ 30.0 30.1 Asif, Saad (2018). 5G Mobile Communications: Concepts and Technologies. CRC Press. pp. 128–134. ISBN 9780429881343.
  31. ↑ Britanak, Vladimir; Rao, K. R. (2017). Cosine-/Sine-Modulated Filter Banks: General Properties, Fast Algorithms and Integer Approximations. Springer. p. 478. ISBN 9783319610801.
  32. ↑ "Receiving NRSC-5". theori.io. Archived from the original on 20 August 2017. Retrieved 14 April 2018.
  33. ↑ Future of IoT will be ‘smart dust’, says Cambridge Consultants, 3 March 2017 (theengineer.co.uk)

Bibliography[]

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