View source for Microwave engineering

{{Short description|Study and design of microwaves}}
'''Microwave engineering''' pertains to the study and design of [[microwave]] circuits, components, and systems. Fundamental principles are applied to analysis, design and measurement techniques in this field. The short [[wavelengths]] involved distinguish this discipline from [[electronic engineering]]. This is because there are different interactions with circuits, transmissions and propagation characteristics at microwave frequencies.

Some theories and devices that pertain to this field are [[antenna (radio)|antennas]], [[radar]], [[transmission line]]s, space based systems ([[remote sensing]]), measurements, microwave radiation hazards and safety measures.

During [[World War II]], microwave engineering played a significant role in developing radar that could accurately locate enemy ships and planes with a focused beam of [[EM radiation]]. The foundations of this discipline are found in [[Maxwell's equations]] and the work of [[Heinrich Hertz]], [[William Thomson, 1st Baron Kelvin|William Thomson]]'s [[waveguide|waveguide theory]], [[J.C. Bose]], the [[klystron]] from Russel and Varian Bross, as well as contributions from Perry Spencer, and others.<ref name=Das>
{{Cite book
  | last =Das 
  | first =Annapurna 
  |author2=Sisir K. Das  
  | title =Microwave engineering  
  | publisher =McGraw-Hill Higher Education 
  | series =McGraw-Hill core concepts in electrical engineering series. 
  | edition =1st 
  | year = 2000–2009
  | url =https://books.google.com/books?id=ZU19Uemy83YC&q=microwave+engineering 
  | isbn =978-0-07-352950-9 
  }}</ref>

==The microwave domain==
[[EM spectrum|Microwave]] is a term used to identify electromagnetic waves above 10<sup>3</sup> megahertz (1 Gigahertz) up to 300 Gigahertz because of the short physical wavelengths of these frequencies. Short [[wavelength]] energy offers distinct advantages in many applications. For instance, sufficient directivity can be obtained using relatively small antennas and low-power transmitters. These characteristics are ideal for use in both military and civilian radar and communication applications. Small antennas and other small components are made possible by microwave frequency applications. The size advantage can be considered as part of a solution to problems of space, or weight, or both. Microwave frequency usage is significant for the design of shipboard radar because it makes possible the detection of smaller targets. Microwave frequencies present special problems in transmission, generation, and circuit design that are not encountered at lower frequencies. Conventional [[circuit theory]] is based on [[voltages]] and [[Electric current|current]]s, while microwave theory is based on [[electromagnetic fields]].<ref name=neetstheory>
{{Cite web
  | title =Module 11 — Microwave Principles 
  | website =Navy Electricity and Electronics Training Series (NEETS)  
  | publisher =[[United States Navy]] 
  | year =1998 
  | url =http://www.phy.davidson.edu/instrumentation/Files/NEETS/Mod11%20-%20Microwave%20Principles.pdf 
  | format =Free PDF download 
  | pages = 1–1 to 1–10 
  | access-date =2011-09-04}} Prepared by FTCM Frank E. Sloan
*{{USGovernment-Navy}}</ref>

Apparatus and techniques may be described qualitatively as "microwave" when the wavelengths of signals are roughly the same as the dimensions of the equipment, so that the [[lumped-element model]] is inaccurate. As a consequence, practical microwave technique tends to move away from the discrete [[resistor]]s, [[capacitor]]s, and [[inductor]]s used with lower frequency [[radio waves]]. Instead, the [[distributed-element model]] and transmission-line theory are more useful methods for design and analysis. Open-wire and coaxial [[transmission line]]s give way to [[waveguide]]s and [[stripline]], and lumped-element tuned circuits are replaced by cavity [[resonator]]s or resonant lines. Effects of [[Reflection (physics)|reflection]], [[Polarization (waves)|polarization]], [[scattering]], [[diffraction]] and atmospheric [[Absorption (electromagnetic radiation)|absorption]] usually associated with visible light are of practical significance in the study of microwave [[Radio propagation|propagation]]. The same [[Maxwell's equations|equations]] of electromagnetic theory apply at all frequencies.<ref name=Das/><ref>This paragraph was directly copied from the Wikipedia article entitled [[Microwave]]. (September 04, 2011). However this material is covered by the reliable source provided in this article (Das, Annapurna; and Sisir K. Das. ''[https://books.google.com/books?id=ZU19Uemy83YC&q=microwave+engineering   Microwave Engineering]''. McGraw-Hill Higher Education).</ref>

==Relevance==
The microwave engineering discipline has become relevant as the [[microwave]] domain moves into the commercial sector, and no longer only applicable to 20th and 21st century [[History of military technology|military technologies]]. Inexpensive components and  digital communications in the microwave domain have opened up areas pertinent to this discipline. Some of these areas are radar, [[satellite]], [[wireless radio]], [[optical communication]], faster computer circuits, and  collision avoidance radar.<ref name=tufts/>

===Education===
Many colleges and universities offer microwave engineering.  A few examples follow.

The [[University of Massachusetts Amherst]] provides  research and educational programs in microwave remote sensing, antenna design and communications systems. Courses and project work are offered leading toward graduate degrees. Specialties include microwave and RF integrated circuit design, antenna engineering, computational electromagnetics, radiowave propagation, radar and remote sensing systems, image processing, and THz imaging.<ref name=umassamherst>
{{cite web
  |title=Research Center & Labs
  |url=http://ece.umass.edu/ece/research-centers
  |publisher=[[University of Massachusetts Amherst]]
  |access-date=18 October 2011
  |format=online web page
  |year=2011}}</ref><ref>
{{Cite web
  |title=Graduate Degrees
  |url=http://ece.umass.edu/ece/graduate/future-students
  |publisher=[[University of Massachusetts Amherst]]
  |access-date=18 October 2011
  |format=online web page
  |year=2011}}</ref>

[[Tufts University]] offers a ''Microwave and Wireless Engineering'' certificate program as part of its graduate studies programs. It can be applied toward a master's degree in electrical engineering. The student must have an appropriate bachelor's degree to enroll in this program.<ref name=tufts>
{{Cite web
  | last =Microwave and Wireless Engineering  
  | title =Certificate program
  | publisher =[[Tufts University]] 
  | year =2011 
  | url =http://gradstudy.tufts.edu/admissions/programs/certificates/microwavewirelesseng.htm 
  | format =online web page 
  | access-date =2011-09-12}}</ref>

[[Auburn University]] offers research for the microwave arena. Wireless Engineering Research and Education Center is one of three research centers. The university also offers a Bachelor of Wireless Engineering degree with a Wireless Electrical Engineering major.<ref name=werec>
{{Cite web
  | last =Research and Outreach  
  | title =Overview  
  | publisher =[[Auburn University]] (Alabama)
  | year =2011 
  | url =http://gradstudy.tufts.edu/admissions/programs/certificates/microwavewirelesseng.htm 
  | format =online web page 
  | access-date =2011-09-12}}</ref><ref>
{{Cite web
  | title =Undergraduate Programs 
  | publisher =[[Auburn University]] (Alabama)
  | year =2011 
  | url =http://www.eng.auburn.edu/elec/programs/index.html
  | format =online web page 
  | access-date =2011-09-12}}</ref><ref>
{{Cite web
  | title =Wireless Engineering Program Options 
  | publisher =[[Auburn University]] (Alabama)
  | year =2011 
  | url =http://www.eng.auburn.edu/wireless/programs/ugrad/options.html
  | format =online web page 
  | access-date =2011-09-12}}</ref>

[[Bradley University]] offers an undergraduate and a graduate degree in its  Microwave and Wireless Engineering Program. It has an Advanced Microwave Laboratory, a Wireless Communication Laboratory and other facilities related to research.<ref name=bradley>
{{Cite web
  | title =Microwave and Wireless Engineering Program
  | publisher =[[Bradley University]] (Illinois)
  | year =2011 
  | url =http://cegt201.bradley.edu/rfpage/
  | format =online web page 
  | access-date =2011-09-12}}</ref>

===Societies===
There are professional societies pertinent to this discipline:

The [[IEEE Microwave Theory and Techniques Society]] (MTT-S) "promotes the advancement of microwave theory and its applications...". The society also publishes peer reviewed journals, and one magazine.<ref name=mtts>
{{Cite web
  | title =About MTT-S 
  | url =http://www.mtt.org/about-mtt.html 
  | format =Online web page 
  | access-date =2011-09-12}}</ref>

===Journals and other scholarly periodicals===
There are peer reviewed journals and other scholarly periodicals that cover topics that pertains to microwave engineering. Some of these are [[IEEE Transactions on Microwave Theory and Techniques]], [[IEEE Microwave and Wireless Components Letters]], Microwave Magazine,<ref>
{{Cite web
  | title =MTT-S Publications
  | url =http://www.mtt.org/publications.html
  | format = Online web page
  | access-date =2011-09-12}}</ref> IET Microwaves, Antennas & Propagation,<ref>
{{Cite web
  | title =IET Microwaves, Antennas and Propagation 
  | publisher =[[Institution of Engineering and Technology]] 
  | url =http://www.ietdl.org/IET-MAP
  | format = Online web page
  | access-date =2011-09-12}}</ref> and Microwave Journal.<ref>
{{Cite web
  | title =Microwave Journal 
  | publisher =[[Horizon House Publications]] 
  | url =http://www.microwavejournal.com
  | format = Online web page
  | access-date =2011-09-12}}</ref>

==See also==
* [[Artificial dielectrics]]
* [[Microwave transmission]]
* [[Radio-frequency engineering]]
* [[Winston E. Kock]]

==References==
{{Reflist}}

==Further reading==
*{{Cite thesis
|degree=PhD 
|title=Microwave Lens Designs : Optimization, Fast simulation algorithms, and 360-degree scanning techniques 
|url=http://hdl.handle.net/10919/29081
|author=Dong, Junwei 
|year=2009 
|publisher=[[Virginia Polytechnic Institute]] and State University 
|hdl= 10919/29081
|access-date=September 26, 2020 
|docket=etd-09242009-195704 
|oclc=469368809}}
{{Engineering fields}}
[[Category:Microwave technology]]
[[Category:Electrical engineering]]