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His research group at Harvard spent the 1940s and 1950s developing the theory of antenna, using the cylindrical antenna as a boundary value problem subject to Maxwell's equations. Also, scattering and diffraction of electromagnetic waves from spheres, cylinders, strips, and disks, conducted within earth, under water or in tissue. [ 5 ]
The two-rays ground-reflection model is a multipath radio propagation model which predicts the path losses between a transmitting antenna and a receiving antenna when they are in line of sight (LOS). Generally, the two antenna each have different height. The received signal having two components, the LOS component and the reflection component ...
The directivity is defined as the ratio of the maximum signal strength S radiated by the antenna to the signal strength S iso radiated by the isotropic antenna = Since the directional antenna radiates most of its power into a small solid angle around the z-axis its maximum signal strength is much larger than the isotropic antenna which spreads ...
The journal covers research on antenna technology and propagation of electromagnetic waves.It also contains topical reviews, and perspective articles. It was established in 2020, with Konstantina Nikita (National Technical University of Athens) as the founding editor-in-chief.
Omnidirectional radiation patterns are produced by the simplest practical antennas, monopole and dipole antennas, consisting of one or two straight rod conductors on a common axis. Antenna gain (G) is defined as antenna efficiency (e) multiplied by antenna directivity (D) which is expressed mathematically as: =.
Friis' original idea behind his transmission formula was to dispense with the usage of directivity or gain when describing antenna performance. In their place is the descriptor of antenna capture area as one of two important parts of the transmission formula that characterizes the behavior of a free-space radio circuit.
Microwave lenses can be classified into two types by the propagation speed of the radio waves in the lens material: [2] Delay lens (slow wave lens): in this type the radio waves travel slower in the lens medium than in free space; the index of refraction is greater than one, so the path length is increased by passing through the lens medium.
International Journal of Antennas and Propagation is a peer reviewed, scientific open access journal that publishes original and review articles in all areas of antennas and propagation. The editor-in-chief is Slawomir Koziel.