Definition of antenna. / ænˈten.iː /. (aerial) (elettronica) antenna nf sostantivo femminile: Identifica un essere, un oggetto o un concetto che assume genere femminile: scrittrice, aquila, lampada, moneta, felicità : We took the antenna off our house and put up a satellite dish. ‘Lurking in these holes, the ants grab the legs and antennae of unsuspecting insects.’ ‘In these fossils, detail of legs, antennae, wings, and even small body hairs are preserved.’ A long thin wire used as a half-wave dipole (or quarter wave monopole) will have a reactance significantly greater than the resistive impedance it has at resonance, leading to a poor match and generally unacceptable performance. All rights reserved.
This page is not one of By adding an inductance in series with the vertical antenna (a so-called The antenna conductors have the lowest feed-point impedance at the resonant frequency where they are just under 1/4 wavelength long; two such conductors in line fed differentially thus realizes the familiar "half-wave dipole". 2 . An example of an inefficient antenna is the simple Hertzian One of the goals of antenna design is to minimize the Once the reactance has been eliminated, what remains is a pure resistance, which is the sum of two parts: the ohmic resistance of the conductors, and the Antennas are typically used in an environment where other objects are present that may have an effect on their performance.
Eyes are gumdrops and jelly beans, antennae are licorice lace, and the tongue is a shaped gumdrop. This is the case for crossed dipoles used in circular polarization antennas.A multi-band rotary directional antenna for amateur radio use.A building rooftop supporting numerous dish and sectored mobile telecommunications antennas (Antenna network for an emergency medical services base station.This entry is from Wikipedia, the leading user-contributed encyclopedia. Outline connects points with 3db field power compared to an ISO emitter. British writers tend to use antennae for both purposes. When fed with an RF current at the resonant frequency, the quarter wave element contains a It can be seen that if such an element is resonant at The use of a monopole or dipole at odd multiples of the fundamental resonant frequency, however, does Although a resonant antenna has a purely resistive feed-point impedance at a particular frequency, many (if not most) applications require using an antenna over a range of frequencies. There is no prescription, or even recommendation, on the form of the plural of It contains the advice or opinions of one or more Wikipedia contributors.
Sort of.Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!Learn a new word every day. For example, a dish antenna on a spacecraft is a high-gain device that must be pointed at the planet to be effective, whereas a typical In practice, the half-wave dipole is taken as a reference instead of the isotropic radiator.
Antenna definition, a conductor by which electromagnetic waves are sent out or received, consisting commonly of a wire or set of wires; aerial. The dipole antenna, which is the basis for most antenna designs, is a Antennas fancier than the dipole or vertical designs are usually intended to increase the directivity and consequently the gain of the antenna. Clearly, at least in Brown's eyes, the distinction in the form of the plural is not between biological and electrical usage, but between formal and informal usage. One can postulate a From this definition, the currents and voltages applied in a set of coupled antennas are:In some geometrical settings, the mutual impedance between antennas can be zero. It turns out that the amount of reactance seen at the terminals of a resonant antenna when the frequency is shifted, say, by 5%, depends very much on the diameter of the conductor used. By using our services, you agree to our use of cookies. For horizontal polarization, there is always a minimum at earth level.
Antennas are essential components of all equipment that uses Typically an antenna consists of an arrangement of metallic Antennas may also contain reflective or directive elements or surfaces not connected to the transmitter or receiver, such as The first antennas were built in 1888 by German physicist Antennas are required by any radio receiver or transmitter to couple its electrical connection to the electromagnetic field. The plural form of antenna is antennae or antennas . See more. When the irregularities of the surface are smaller than the wavelength, reflection is good.This means that the receptor "sees" the real antenna and, under the ground, the image of the antenna reflected by the ground.
They all have vertical antennas or horizontal Classical (analog) television emissions are an exception. As word admitted into English language, 'antennas' is so correct as 'antennae'. Transmitters mounted on vehicles with large motional freedom commonly use circularly polarized antennasMaximum power transfer requires matching the impedance of an antenna system (as seen looking into the transmission line) to the Antenna tuning generally refers to cancellation of any reactance seen at the antenna terminals, leaving only a resistive impedance which might or might not be exactly the desired impedance (that of the transmission line).
Antenna in Latin was the yardarm of a ship, whereas today antenna means no such thing, even though both the word antenna, in use thousands of years ago in Latin, is spelled exactly the same as the word antenna used in modern English. EcoCookies help us deliver our services. Word Origin mid 17th cent. Plural: Antennae. But waves emitted to the ground at grazing angles, far from the antenna, are almost totally reflected. A vertical Polarization is the sum of the E-plane orientations over time projected onto an imaginary plane perpendicular to the direction of motion of the radio wave.
/ ænˈten.iː / us. So horizontal should be used with horizontal and vertical with vertical. Through common usage, antennas (which adheres to the standard rules for forming plurals) is also now acceptable. The confusion surrounding the plural of antenna may come from the word’s latinate character. Clearly, at least in Brown's eyes, the distinction in the form of the plural is not between biological and electrical usage, but between formal and informal usage. 3. Intermediate matchings will lose some signal strength, but not as much as a complete mismatch.