Microwave engineering pertains to the study and design ofmicrowave circuits, components, and systems. Fundamental principles are applied to analysis, design and measurement techniques in this field. The shortwavelengths involved distinguish this discipline fromelectronic 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 areantennas,radar,transmission lines, space based systems (remote sensing), measurements, microwave radiation hazards and safety measures.

DuringWorld War II, microwave engineering played a significant role in developing radar that could accurately locate enemy ships and planes with a focused beam ofEM radiation. The foundations of this discipline are found inMaxwell's equations and the work ofHeinrich Hertz,William Thomson'swaveguide theory,J.C. Bose, theklystron from Russel and Varian Bross, as well as contributions from Perry Spencer, and others.^[1]

Microwave is a term used to identify electromagnetic waves above 10³ megahertz (1 Gigahertz) up to 300 Gigahertz because of the short physical wavelengths of these frequencies. Shortwavelength 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. Conventionalcircuit theory is based onvoltages andcurrents, while microwave theory is based onelectromagnetic fields.^[2]

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 thelumped-element model is inaccurate. As a consequence, practical microwave technique tends to move away from the discreteresistors,capacitors, andinductors used with lower frequencyradio waves. Instead, thedistributed-element model and transmission-line theory are more useful methods for design and analysis. Open-wire and coaxialtransmission lines give way towaveguides andstripline, and lumped-element tuned circuits are replaced by cavityresonators or resonant lines. Effects ofreflection,polarization,scattering,diffraction and atmosphericabsorption usually associated with visible light are of practical significance in the study of microwavepropagation. The sameequations of electromagnetic theory apply at all frequencies.^[1][3]

The microwave engineering discipline has become relevant as themicrowave domain moves into the commercial sector, and no longer only applicable to 20th and 21st centurymilitary 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.^[4]

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

TheUniversity 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.^[5][6]

Tufts University offers aMicrowave 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.^[4]

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.^[7][8][9]

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.^[10]

There are professional societies pertinent to this discipline:

TheIEEE 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.^[11]

There are peer reviewed journals and other scholarly periodicals that cover topics that pertains to microwave engineering. Some of these areIEEE Transactions on Microwave Theory and Techniques,IEEE Microwave and Wireless Components Letters, Microwave Magazine,^[12] IET Microwaves, Antennas & Propagation,^[13] and Microwave Journal.^[14]

• Artificial dielectrics
• Microwave transmission
• Radio-frequency engineering
• Winston E. Kock

• Dong, Junwei (2009).Microwave Lens Designs : Optimization, Fast simulation algorithms, and 360-degree scanning techniques (PhD thesis).Virginia Polytechnic Institute and State University.hdl:10919/29081.OCLC 469368809. Docket etd-09242009-195704. RetrievedSeptember 26, 2020.