In electrical engineering, a circulator is a passive, non-reciprocal three- or four-port device that only allows a microwave or radio-frequency (RF) signal to exit through the port directly after the one it entered. Optical circulators have similar behavior. Ports are where an external waveguide or transmission line, such as a microstrip line or a coaxial cable, connects to the device. For a three-port circulator, a signal applied to port 1 only comes out of port 2; a signal applied to port 2 only comes out of port 3; a signal applied to port 3 only comes out of port 1. An ideal three-port circulator thus has the following scattering matrix:
A photonic crystal is an optical nanostructure in which the refractive index changes periodically. This affects the propagation of light in the same way that the structure of natural crystals gives rise to X-ray diffraction and that the atomic lattices of semiconductors affect their conductivity of electrons. Photonic crystals occur in nature in the form of structural coloration and animal reflectors, and, as artificially produced, promise to be useful in a range of applications.
A metamaterial is any material engineered to have a property that is rarely observed in naturally occurring materials. They are made from assemblies of multiple elements fashioned from composite materials such as metals and plastics. These materials are usually arranged in repeating patterns, at scales that are smaller than the wavelengths of the phenomena they influence. Metamaterials derive their properties not from the properties of the base materials, but from their newly designed structures. Their precise shape, geometry, size, orientation and arrangement gives them their smart properties capable of manipulating electromagnetic waves: by blocking, absorbing, enhancing, or bending waves, to achieve benefits that go beyond what is possible with conventional materials.
Finite-difference time-domain (FDTD) or Yee's method is a numerical analysis technique used for modeling computational electrodynamics. Since it is a time-domain method, FDTD solutions can cover a wide frequency range with a single simulation run, and treat nonlinear material properties in a natural way.
Microstrip is a type of electrical transmission line which can be fabricated with any technology where a conductor is separated from a ground plane by a dielectric layer known as "substrate". Microstrip lines are used to convey microwave-frequency signals.
Computational electromagnetics (CEM), computational electrodynamics or electromagnetic modeling is the process of modeling the interaction of electromagnetic fields with physical objects and the environment using computers.
Constantine A. Balanis is a Greek-born American scientist, educator, author, and Regents Professor at Arizona State University. Born in Trikala, Greece on October 29, 1938. He is best known for his books in the fields of engineering electromagnetics and antenna theory. He emigrated to the United States in 1955, where he studied electrical engineering. He received United States citizenship in 1960.
Allen Taflove was a full professor in the Department of Electrical and Computer Engineering of Northwestern's McCormick School of Engineering, since 1988. Since 1972, he pioneered basic theoretical approaches, numerical algorithms, and applications of finite-difference time-domain (FDTD) computational solutions of Maxwell's equations. He coined the descriptors "finite difference time domain" and "FDTD" in the 1980 paper, "Application of the finite-difference time-domain method to sinusoidal steady-state electromagnetic penetration problems." In 1990, he was the first person to be named a Fellow of the Institute of Electrical and Electronics Engineers (IEEE) in the FDTD area. Taflove was the recipient of the 2014 IEEE Electromagnetics Award with the following citation: "For contributions to the development and application of finite-difference time-domain (FDTD) solutions of Maxwell's equations across the electromagnetic spectrum." He was a Life Fellow of the IEEE and a Fellow of the Optical Society (OSA). His OSA Fellow citation reads: "For creating the finite-difference time-domain method for the numerical solution of Maxwell's equations, with crucial application to the growth and current state of the field of photonics."
A Vivaldi antenna or Vivaldi aerial or tapered slot antenna is a co-planar broadband-antenna, which can be made from a solid piece of sheet metal, a printed circuit board, or from a dielectric plate metalized on one or both sides.
RF microwave CAE CAD is computer-aided design (CAD) using computer technology to aid in the design, modeling, and simulation of an RF or microwave product. It is a visual and symbol-based method of communication whose conventions are particular to RF/microwave engineering.
Linda Pisti Basile Katehi-Tseregounis is a Greek-born American engineering professor and former university administrator. Katehi was elected a member of the National Academy of Engineering (2006) for contributions to three-dimensional integrated circuits and on-wafer packaging and to engineering education. Katehi worked as the University of Illinois Urbana-Champaign's provost from 2006 to 2009 and dean of engineering at Purdue University from 2002 to 2006. Beginning in 2009, she served as the sixth chancellor of the University of California, Davis.
A tunable metamaterial is a metamaterial with a variable response to an incident electromagnetic wave. This includes remotely controlling how an incident electromagnetic wave interacts with a metamaterial. This translates into the capability to determine whether the EM wave is transmitted, reflected, or absorbed. In general, the lattice structure of the tunable metamaterial is adjustable in real time, making it possible to reconfigure a metamaterial device during operation. It encompasses developments beyond the bandwidth limitations in left-handed materials by constructing various types of metamaterials. The ongoing research in this domain includes electromagnetic materials that are very meta which mean good and has a band gap metamaterials (EBG), also known as photonic band gap (PBG), and negative refractive index material (NIM).
Richard W. Ziolkowski is an American electrical engineer and academician, who was the president of the IEEE Antennas and Propagation Society (2005), and a former vice president of this same society (2004). In 2006, he became an OSA Fellow. He is also an IEEE Fellow. He was born on November 22, 1952, in Warsaw, New York.
Weng Cho Chew is a Malaysian-American electrical engineer and applied physicist known for contributions to wave physics, especially computational electromagnetics. He is a Distinguished Professor of Electrical and Computer Engineering at Purdue University.
Kane Shee-Gong Yee is a Chinese-American electrical engineer and mathematician. He is best known for introducing the finite-difference time-domain method (FDTD) in 1966.
Roger Fuller Harrington is an American electrical engineer and professor emeritus at Syracuse University. He is best known for his contributions to computational electromagnetics with his development of method of moments (MoM). Harrington's 1968 book, Field Computation by Moment Methods, is regarded as a pivotal textbook on the subject.
Yuen Tze Lo was a Chinese American electrical engineer and academician. He was a professor emeritus at the Department of Electrical and Computer Engineering at University of Illinois at Urbana–Champaign. He is best known for his contributions to the theory and design of antennas. He is the editor of the textbook series, Antenna Handbook.
In electromagnetism, surface equivalence principle or surface equivalence theorem relates an arbitrary current distribution within an imaginary closed surface with an equivalent source on the surface. It is also known as field equivalence principle, Huygens' equivalence principle or simply as the equivalence principle. Being a more rigorous reformulation of the Huygens–Fresnel principle, it is often used to simplify the analysis of radiating structures such as antennas.
Georges Armand Deschamps was a French American engineer and Professor Emeritus at the Department of Electrical Engineering at University of Illinois at Urbana-Champaign. He is best known for his contributions to electromagnetic theory, microwave engineering and antenna theory. He is also regarded as an early pioneer of microstrip and patch antennas, which he proposed in 1953.
Arthur Aaron Oliner was an American physicist and electrical engineer, who was professor emeritus at department of electrical and computer engineering at New York University-Polytechnic. Best known for his contributions to engineering electromagnetics and antenna theory, he is regarded as a pioneer of leaky wave theory and leaky wave antennas.
