View source for Radio-frequency engineering

{{Short description|Specialty of electronic engineering}}
{{More citations needed|date=May 2008}}
{{Infobox Occupation
| name               = Radio-frequency engineering
| image              = 
| caption            = 
| official_names     = Radio-frequency engineer
* [[Outside broadcasting|Outside broadcast]] radio-frequency engineer
<!------------Details------------------->
| type               = [[Profession]]
| activity_sector    = 
| competencies       = Technical knowledge, management skills
| formation          = [[Mathematics]], [[physics]], [[electronics]], [[information technology]]
| employment_field   = Radio, television, military
| related_occupation = [[Technology|Technologist]], [[broadcast engineer]], [[engineering technician]], [[technical operator]]
| average_salary     = 
}}
{{Electromagnetism}}

'''Radio-frequency (RF) engineering''' is a subset of [[electrical engineering]] involving the application of [[transmission line]], [[Waveguide (electromagnetism)|waveguide]], [[Antenna (radio)|antenna]] and [[Electromagnetic radiation|electromagnetic field]] principles to the design and application of devices that produce or use signals within the [[radio band]], the frequency range of about 20&nbsp;[[Hertz#SI multiples|kHz]] up to 300&nbsp;[[Hertz#SI multiples|GHz]].<ref>A. A. Ghirardi, ''Radio Physics Course'', 2nd ed. New York: Rinehart Books, 1932, p. 249</ref><ref>[https://archive.org/stream/principlesunderl00unitrich#page/190/mode/2up Signal Corps U.S. Army, ''The Principles Underlying Radio Communication'', 2nd ed. Washington, DC: U.S.G.P.O., 1922, p. 191]</ref><ref name="TM11-665">{{cite book
  | title = Technical Manual TM 11-665: C-W and A-M Radio Transmitters and Receivers
  | publisher = Dept. of the Army, US Government Printing Office
  | date = 1952
  | pages = 2
  | url = https://books.google.com/books?id=f9QXAAAAYAAJ&pg=PA2
  }}</ref>

It is incorporated into almost everything that transmits or receives a [[radio wave]], which includes, but is not limited to, mobile phones, radios, [[Wi-Fi]], and two-way radios.
RF engineering is a highly specialized field that typically includes the following areas of expertise:
# Design of antenna systems to provide radiative coverage of a specified geographical area by an electromagnetic field or to provide specified sensitivity to an electromagnetic field impinging on the antenna.
# Design of coupling and transmission line structures to transport RF energy without radiation.
# Application of circuit elements and transmission line structures in the design of oscillators, amplifiers, mixers, detectors, combiners, filters, impedance transforming networks and other devices.
# Verification and measurement of performance of radio frequency devices and systems.<ref>{{cite web| title = How to Measure Requirement for RF Equipments| date = 30 January 2018| url = http://ranatec.com/how-to-measure-requirement-for-rf-equipments/}}</ref>
To produce quality results, the RF engineer needs to have an in-depth knowledge of [[mathematics]], [[physics]] and general [[electronics]] theory as well as specialized training in areas such as wave propagation, impedance transformations, filters and microstrip printed circuit board design.{{Citation needed|date=March 2021}}

==Radio electronics==
''Radio electronics'' is concerned with [[electronics|electronic]] [[electrical network|circuits]] which receive or transmit [[radio]] signals.

Typically, such circuits must operate at [[radio frequency]] and power levels, which imposes special constraints on their design. These constraints increase in their importance with higher frequencies. At [[microwave]] frequencies, the [[Reactance (electronics)|reactance]] of [[signal trace]]s becomes a crucial part of the physical layout of the circuit.

List of radio electronics topics:

* [[Radio frequency|RF]] [[oscillator]]s: [[Phase-locked loop]], [[voltage-controlled oscillator]]
* [[Transmitter]]s, [[transmission line]]s, [[RF connector]]s
* [[Antenna (electronics)|Antenna]]s, [[antenna theory]]
* [[Radio receiver|Receiver]]s, [[tuner (radio)|tuner]]s
* [[Electronic amplifier|Amplifier]]s
* [[Modulator]]s, [[demodulator]]s, [[detector (radio)|detector]]s
* [[RF and microwave filter|RF filter]]s
* [[RF shielding]], [[ground plane]]
* [[Direct-sequence spread spectrum]] (DSSS), [[noise power]]
* [[Digital radio]]
* [[RF power amplifier]]s
** [[MOSFET|Metal–oxide–semiconductor field-effect transistor (MOSFET)]]s: [[Power MOSFET]], [[LDMOS|Laterally-diffused metal-oxide semiconductor (LDMOS)]]
** [[Bipolar junction transistors]]
* [[Baseband processor]]s ([[CMOS|Complementary metal–oxide–semiconductor (CMOS)]])
* [[RF CMOS]] ([[mixed-signal]] [[integrated circuits]])

==Duties==
[[File:Felder_um_Dipol.jpg|thumb|260x260px|Diagram of the [[electric field]]s ''<span style="color:blue;">(blue)</span>'' and [[magnetic field]]s ''<span style="color:red;">(red)</span>'' radiated by a [[dipole antenna]] ''(black rods)'' during transmission.]]
Radio-frequency engineers are specialists in their respective field and can take on many different roles, such as design, installation, and maintenance.  Radio-frequency engineers require many years of extensive experience in the area of study.  This type of engineer has experience with transmission systems, device design, and placement of antennas for optimum performance. 
The RF engineer job description at a broadcast facility can include maintenance of the station's high-power broadcast transmitters and associated systems. This includes transmitter site emergency power, remote control, main transmission line and [[Antenna (radio)|antenna]] adjustments, [[microwave radio relay]] [[Studio/transmitter link|STL]]/[[Transmitter/studio link|TSL]] links, and more.

In addition, a radio-frequency design engineer must be able to understand electronic hardware design, circuit board material, antenna radiation, and the effect of interfering frequencies that prevent optimum performance within the piece of equipment being developed.

==Mathematics==
There are many applications of [[electrodynamics|electromagnetic theory]] to radio-frequency engineering, using conceptual tools such as [[vector calculus]] and [[complex analysis]].<ref>{{Cite book|url=https://books.google.com/books?id=kIeKDQAAQBAJ|title=Introduction to Radio Engineering|last1=Blaunstein|first1=Nathan|last2=Christodoulou|first2=Christos|last3=Sergeev|first3=Mikhail|date=2016-10-14|publisher=[[CRC Press]]|isbn=9781315350080|language=en}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=m8Dgkvf84xoC|title=Radio Engineering for Wireless Communication and Sensor Applications|last1=Räisänen|first1=Antti V.|last2=Lehto|first2=Arto|date=2003|publisher=[[Artech House]]|isbn=9781580536691|language=en}}</ref> Topics studied in this area include [[Waveguide (electromagnetism)|waveguides]] and [[transmission line]]s, the behavior of [[Antenna (radio)|radio antennas]], and the [[Radio propagation|propagation of radio waves]] through the Earth's atmosphere. Historically, the subject played a significant role in the development of [[nonlinear dynamics]].<ref>{{Cite book|url=https://sites.google.com/site/giorgioisrael/Art92.pdf|title=Technological Concepts and Mathematical Models in the Evolution of Modern Engineering Systems|last=Israel|first=Giorgio|date=2004|publisher=[[Birkhäuser]], Basel|isbn=9783034896337|pages=52–77|language=en|chapter=Technological Innovation and New Mathematics: van der Pol and the Birth of Nonlinear Dynamics|doi=10.1007/978-3-0348-7951-4_3}}</ref>

==See also==
{{Portal|Television|Engineering|Technology and applied sciences}}
{{main category|Radio electronics}}
* [[Broadcast engineering]]
* [[Information theory]]
* [[Microwave engineering]]
* [[Overlap zone]]
* [[Radio resource management]]
* [[Radio-frequency current]]
* [[SPLAT!|SPLAT! (software)]]
*[[List of textbooks in electromagnetism]]

==References==
{{reflist}}

== External links ==
* [https://www.allaboutcircuits.com/textbook/radio-frequency-analysis-design/ Practical Guide to Radio-Frequency Analysis and Design]

{{Engineering fields}}
{{Authority control}}

[[Category:Radio spectrum]]
[[Category:Radio technology|Radio waves]]
[[Category:Waves|Radio waves]]
[[Category:Electromagnetic spectrum]]
[[Category:Broadcast engineering]]
[[Category:Electrical engineering]]
[[Category:Electronic engineering]]
[[Category:Broadcasting occupations]]
[[Category:Engineering occupations]]
[[Category:MOSFETs]]
[[Category:Telecommunications techniques]]