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Dual-band Blade Antenna
A dual-band blade antenna, is a type of ''blade antenna'', a monopole whip antenna mounted on the outside of an aircraft in the form of a blade-shaped aerodynamic fairing to reduce its air drag. It is used by avionics radio communication systems. The dual band type uses a "plane and slot" design to get efficient omni-directional coverage so that it can operate on two different radio bands. Introduction A typical monopole antenna has an omnidirectional radiation pattern; it radiates equal radio power in all azimuthal directions perpendicular to the antenna axis, with the signal power decreasing with elevation angle to a null (point of zero radiated power) at the zenith. A monopole antenna can be thought of as a dipole antenna where one end of the dipole antenna now becomes the ground plane for said monopole antenna. By this line of conceptual thinking, one can easily reach the conclusion that the radiation emanating from a monopole antenna exists in half the space of si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JMSDF MCH-101(8657) Blade Antenna Right Front View At Maizuru Air Station May 18, 2019
, abbreviated , also simply known as the Japanese Navy, is the maritime warfare branch of the Japan Self-Defense Forces, tasked with the naval defense of Japan. The JMSDF was formed following the dissolution of the Imperial Japanese Navy (IJN) after World War II. The JMSDF has a fleet of 154 ships, 346 aircraft and 50,800 personnel. History Origin Following Japan's defeat in World War II, the Imperial Japanese Navy was dissolved by the Potsdam Declaration acceptance. Ships were disarmed, and some of them, such as the battleship , were taken by the Allied Powers as reparation. The remaining ships were used for repatriation of the Japanese soldiers from abroad and also for minesweeping in the area around Japan, initially under the control of the ''Second Bureau of the Demobilization Ministry''. The minesweeping fleet was eventually transferred to the newly formed Maritime Safety Agency, which helped maintain the resources and expertise of the navy. Japan's 1947 Constitution ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerodynamics
Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dynamics and its subfield of gas dynamics. The term ''aerodynamics'' is often used synonymously with gas dynamics, the difference being that "gas dynamics" applies to the study of the motion of all gases, and is not limited to air. The formal study of aerodynamics began in the modern sense in the eighteenth century, although observations of fundamental concepts such as aerodynamic drag were recorded much earlier. Most of the early efforts in aerodynamics were directed toward achieving Aircraft#Heavier than air – aerodynes, heavier-than-air flight, which was first demonstrated by Otto Lilienthal in 1891. Since then, the use of aerodynamics through mathematical analysis, empirical approximations, wind tunnel experimentation, and computer simu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dual Band Blade Antenna Model
Dual or Duals may refer to: Paired/two things * Dual (mathematics), a notion of paired concepts that mirror one another ** Dual (category theory), a formalization of mathematical duality *** see more cases in :Duality theories * Dual (grammatical number), a grammatical category used in some languages * Dual county, a Gaelic games county which in both Gaelic football and hurling * Dual diagnosis, a psychiatric diagnosis of co-occurrence of substance abuse and a mental problem * Dual fertilization, simultaneous application of a P-type and N-type fertilizer * Dual impedance, electrical circuits that are the dual of each other * Dual SIM cellphone supporting use of two SIMs * Aerochute International Dual a two-seat Australian powered parachute design Acronyms and other uses * Dual (brand), a manufacturer of Hifi equipment * DUAL (cognitive architecture), an artificial intelligence design model * DUAL algorithm, or diffusing update algorithm, used to update Internet protocol rou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wavelength
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, troughs, or zero crossings, and is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns. The inverse of the wavelength is called the spatial frequency. Wavelength is commonly designated by the Greek letter ''lambda'' (λ). The term ''wavelength'' is also sometimes applied to modulated waves, and to the sinusoidal envelopes of modulated waves or waves formed by interference of several sinusoids. Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to frequency of the wave: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths. Wavelength depends on the medium (for example, vacuum, air, or water) that a wav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FEKO
Feko is a computational electromagnetics software product developed by Altair Engineering. The name is derived from the German acronym "Feldberechnung für Körper mit beliebiger Oberfläche", which can be translated as "field calculations involving bodies of arbitrary shape". It is a general purpose 3D electromagnetic (EM) simulator. FEKO originated in 1991 from research activities of Dr. Ulrich Jakobus at the University of Stuttgart, Germany. Cooperation between Dr. Jakobus and EM Software & Systems (EMSS) resulted in the commercialisation of FEKO in 1997. In June 2014, Altair Engineering acquired 100% of EMSS-S.A. and its international distributor offices in the United States, Germany and China, leading to the addition of FEKO to the Altair Hyperworks suite of engineering simulation software. The software is based on the Method of Moments (MoM) integral formulation of Maxwell's equations and pioneered the commercial implementation of various hybrid methods such as: * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Babinet's Principle
In physics, Babinet's principle states that the diffraction pattern from an opaque body is identical to that from a hole of the same size and shape except for the overall forward beam intensity. It was formulated in the 1800s by French physicist Jacques Babinet. A quantum version of Babinet's principle has been derived in the context of quantum networks. State transfer in highly connected networks and a quantum Babinet principle, D. I. Tsomokos, M. B. Plenio, I. de Vega, and S. F. Huelga, Phys. Rev. A 78, 062310 (2008) Explanation Assume ''B'' is the original diffracting body, and ''B is its complement, i.e., a body that is transparent. The sum of the radiation patterns caused by ''B'' and ''B must be the same as the radiation pattern of the unobstructed beam. In places where the undisturbed beam would not have reached, this means that the radiation patterns caused by ''B'' and ''B must be opposite in phase, but equal in amplitude. Diffraction patterns from apertures or bodies o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permittivity
In electromagnetism, the absolute permittivity, often simply called permittivity and denoted by the Greek letter ''ε'' ( epsilon), is a measure of the electric polarizability of a dielectric. A material with high permittivity polarizes more in response to an applied electric field than a material with low permittivity, thereby storing more energy in the material. In electrostatics, the permittivity plays an important role in determining the capacitance of a capacitor. In the simplest case, the electric displacement field D resulting from an applied electric field E is :\mathbf = \varepsilon \mathbf. More generally, the permittivity is a thermodynamic function of state. It can depend on the frequency, magnitude, and direction of the applied field. The SI unit for permittivity is farad per meter (F/m). The permittivity is often represented by the relative permittivity ''ε''r which is the ratio of the absolute permittivity ''ε'' and the vacuum permittivity ''ε''0 :\kappa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permeability (electromagnetism)
In electromagnetism, permeability is the measure of magnetization that a material obtains in response to an applied magnetic field. Permeability is typically represented by the (italicized) Greek letter ''μ''. The term was coined by William Thomson, 1st Baron Kelvin in 1872, and used alongside permittivity by Oliver Heaviside in 1885. The reciprocal of permeability is magnetic reluctivity. In SI units, permeability is measured in henries per meter (H/m), or equivalently in newtons per ampere squared (N/A2). The permeability constant ''μ''0, also known as the magnetic constant or the permeability of free space, is the proportionality between magnetic induction and magnetizing force when forming a magnetic field in a classical vacuum. A closely related property of materials is magnetic susceptibility, which is a dimensionless proportionality factor that indicates the degree of magnetization of a material in response to an applied magnetic field. Explanation In the mac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
