engineering
This article is about the generic oscillation. For the radiation, see radio wave. For the spectrum, see radio spectrum. For the electronics, see radio-frequency engineering.
"RF" redirects here. For the CMOS chip, see RF CMOS.

Radio frequency (RF) is a frequency or rate of oscillation within the range of about 3 Hz to 300 GHz. This range corresponds to frequency of alternating current electrical signals used to produce and detect radio waves. Since most of this range is beyond the vibration rate that most mechanical systems can respond to, RF usually refers to oscillations in electrical circuits or electromagnetic radiation.

RF is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around 20 kHz to around 300 GHz. This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies;[1][2] these are the frequencies at which energy from an oscillating current can radiate off a conductor into space as radio waves. Different sources specify different upper and lower bounds for the frequency range.

Electric current

Electric currents that oscillate at radio frequencies (RF currents) have special properties not shared by direct current or alternating current of lower frequencies.

Frequency bands

Main article: Radio spectrum

The radio spectrum of frequencies is divided into bands with conventional names designated by the International Telecommunications Union (ITU):

Frequency
range		 Wavelength
range		 ITU designation IEEE bands[5]
Full name Abbreviation[6]
3–30 Hz 105–104 km Extremely low frequency ELF —
30–300 Hz 104–103 km Super low frequency SLF —
300–3000 Hz 103–100 km Ultra low frequency ULF —
3–30 kHz 100–10 km Very low frequency VLF —
30–300 kHz 10–1 km Low frequency LF —
300 kHz – 3 MHz 1 km – 100 m Medium frequency MF —
3–30 MHz 100–10 m High frequency HF HF
30–300 MHz 10–1 m Very high frequency VHF VHF
300 MHz – 3 GHz 1 m – 10 cm Ultra high frequency UHF UHF, L, S
3–30 GHz 10–1 cm Super high frequency SHF S, C, X, Ku, K, Ka
30–300 GHz 1 cm – 1 mm Extremely high frequency EHF Ka, V, W, mm
300 GHz – 3 THz 1 mm – 0.1 mm Tremendously high frequency THF —

Frequencies of 1 GHz and above are conventionally called microwave,[7] while frequencies of 30 GHz and above are designated millimeter wave. More detailed band designations are given by the standard IEEE letter- band frequency designations[5] and the EU/NATO frequency designations.[8]

Applications

Communications

Radio frequencies are generated and processed within very many functional units such as transmitters, receivers, computers, televisions, and mobile phones, to name a few. Radio frequencies are also applied in carrier current systems including telephony and control circuits.

RF circuit technology is widely used in wireless telecommunications, such as mobile communication. A typical smartphone contains a number of metal–oxide–semiconductor (MOS) integrated circuit (IC) RF chips, including RF CMOS chips such as a baseband cellular modem, RF transceiver, and wireless communication chips (Wi-Fi, Bluetooth, and GPS receiver),[9] as well as LDMOS (lateral diffused MOS) RF power amplifiers.[10][11][12]

Medicine

Main article: Medical applications of radio frequency

Radio frequency (RF) energy, in the form of radiating waves or electrical currents, has been used in medical treatments for over 75 years,[13] generally for minimally invasive surgeries using radiofrequency ablation including the treatment of sleep apnea.[14]

RF energy

RF energy, also known as solid-state RF energy, is an electronic technology that uses solid-state electronics to provide RF electromagnetic radiation in a controlled manner for a wide range of applications, such as heating and home appliances. RF energy was introduced in the 2010s, as a replacement of traditional cavity magnetron tubes previously used for appliances such as microwave ovens.[15][16]

The basis for RF energy technology is the LDMOS (laterally-diffused metal–oxide–semiconductor) transistor.[17][18][19] Common applications of LDMOS-based RF energy technology include the following.

Measurement

Test apparatus for radio frequencies can include standard instruments at the lower end of the range, but at higher frequencies the test equipment becomes more specialized.

Mechanical oscillations

While RF usually refers to electrical oscillations, mechanical RF systems are not uncommon: see mechanical filter and RF MEMS.

See also

References

  1. ↑ J. A. Fleming, The Principles of Electric Wave Telegraphy and Telephony, London: Longmans, Green & Co., 1919, p. 364
  2. ↑ A. A. Ghirardi, Radio Physics Course, 2nd ed. New York: Rinehart Books, 1932, p. 249
  3. ↑ Curtis, Thomas Stanley (1916). High Frequency Apparatus: Its Construction and Practical Application. USA: Everyday Mechanics Company. p. 6.
  4. ↑ Mieny, C. J. (2003). Principles of Surgical Patient Care (2nd ed.). New Africa Books. p. 136. ISBN 9781869280055.
  5. ↑ 5.0 5.1 IEEE Std 521-2002 Standard Letter Designations for Radar-Frequency Bands Archived 2013-12-21 at the Wayback Machine, Institute of Electrical and Electronics Engineers, 2002. (Convenience copy at National Academies Press.)
  6. ↑ Jeffrey S. Beasley; Gary M. Miller (2008). Modern Electronic Communication (9th ed.). pp. 4–5. ISBN 978-0132251136.
  7. ↑ Kumar, Sanjay; Shukla, Saurabh (2014). Concepts and Applications of Microwave Engineering. PHI Learning Pvt. Ltd. p. 3. ISBN 978-8120349353.
  8. ↑ Leonid A. Belov; Sergey M. Smolskiy; Victor N. Kochemasov (2012). Handbook of RF, Microwave, and Millimeter-Wave Components. Artech House. pp. 27–28. ISBN 978-1-60807-209-5.
  9. ↑ Kim, Woonyun (2015). "CMOS power amplifier design for cellular applications: an EDGE/GSM dual-mode quad-band PA in 0.18 μm CMOS". In Wang, Hua; Sengupta, Kaushik (eds.). RF and mm-Wave Power Generation in Silicon. Academic Press. pp. 89–90. ISBN 978-0-12-409522-9.
  10. ↑ Baliga, Bantval Jayant (2005). Silicon RF Power MOSFETS. World Scientific. pp. 1–2. ISBN 9789812561213.
  11. ↑ "White Paper – 50V RF LDMOS: An ideal RF power technology for ISM, broadcast and commercial aerospace applications" (PDF). NXP Semiconductors. Freescale Semiconductor. September 2011. Retrieved 4 December 2019.
  12. ↑ 12.0 12.1 12.2 Theeuwen, S. J. C. H.; Qureshi, J. H. (June 2012). "LDMOS Technology for RF Power Amplifiers" (PDF). IEEE Transactions on Microwave Theory and Techniques. 60 (6): 1755–1763. doi:10.1109/TMTT.2012.2193141. ISSN 1557-9670.
  13. ↑ Ruey J. Sung; Michael R. Lauer (2000). Fundamental approaches to the management of cardiac arrhythmias. Springer. p. 153. ISBN 978-0-7923-6559-4. Archived from the original on 2015-09-05. {{cite book}}: Unknown parameter |lastauthoramp= ignored (|name-list-style= suggested) (help)
  14. ↑ Melvin A. Shiffman; Sid J. Mirrafati; Samuel M. Lam; Chelso G. Cueteaux (2007). Simplified Facial Rejuvenation. Springer. p. 157. ISBN 978-3-540-71096-7.
  15. ↑ "Solid-State RF Energy Technology". RF Energy Alliance. Retrieved 21 December 2019.
  16. ↑ "What is RF Energy?". PinkRF. Retrieved 21 December 2019.
  17. ↑ 17.0 17.1 17.2 17.3 17.4 17.5 Torres, Victor (21 June 2018). "Why LDMOS is the best technology for RF energy". Microwave Engineering Europe. Ampleon. Retrieved 10 December 2019.
  18. ↑ 18.0 18.1 "915 MHz RF Cooking". NXP Semiconductors. Retrieved 7 December 2019.
  19. ↑ 19.0 19.1 19.2 19.3 19.4 "LDMOS Products and Solutions". NXP Semiconductors. Retrieved 4 December 2019.
  20. ↑ "1-600 MHz – Broadcast and ISM". NXP Semiconductors. Retrieved 12 December 2019.
  21. ↑ 21.0 21.1 21.2 "ISM & Broadcast". ST Microelectronics. Retrieved 3 December 2019.
  22. ↑ 22.0 22.1 22.2 "RF Defrosting". NXP Semiconductors. Retrieved 12 December 2019.

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