A Wi-Fi antenna acts as a magnet for wireless Internet signals, allowing electronic devices like routers, smartphones, and laptops to connect. Sometimes you need to integrate Wi-Fi antennas into devices that do not have this technology built in. When you need a wireless connection on a laptop that does not support Wi-Fi, use a USB Wi-Fi antenna, which plugs into any USB port on the device and provides near-instant access. Use a long-range Wi-Fi antenna to pick up a signal from miles away through point-to-point directional antennas. EBay sellers offer a wide variety of Wi-Fi antennas and boosters.
How to make long range WiFi antenna WIFE and Quadcopters.Pt-1 15 element long range WiFi yagi antenna for 802.11 b/g/n. Good DIY project using simple tools and parts.
Part 2: be sure to see my other videos: 1- Whiten Teeth - You need battery and blue LED 2- What is Arduino?!! ES 01 3- Battery Bank?
The Ukrainian T-shaped Radio telescope UTR-2. With its antenna array of 150,000 square meters, it is the world’s largest low-frequency radio telescope at decametre wavelengths built in 1969 near the village of Hrakovo about 60 km south-west from Kharkov, USSR. The antenna array consists of 2040 broadband cage dipoles. It is interesting to note that the same fully operational Soviet-made radio receivers R-250M2 and other equipment produced in the late 1960s.
This photo was taken in 1973 during the author’s summer internship at the site The Antennas Around Us. Xiaomi MI-5 smartphone antennas: 1 — NFC antenna, 2 — GPS antenna, 3 — Wi-Fi/Bluetooth antenna, 4 — main antenna When I start writing an article for the TranslatorsCafe.com Unit Converter, I often check my pockets, look around, then out the window and calculate things I am writing about. This time I am writing about antennas. So, let’s count:.
Five antennas in my mobile phone Xiaomi Mi-5:. main antenna to communicate with cell towers,. GPS and GLONASS antenna,.
Wi-Fi antenna and Bluetooth antenna. 2.4 GHz 2 dBi Wi-Fi rubber ducky antenna design; left — the assembled antenna, middle and right — the disassembled antenna. This vertically polarized 360° omnidirectional antenna is used for the wireless router. It is essentially a dipole antenna, in which the inner exposed conductor is ¼ wavelength long. The metal sleeve is also ¼ wavelength long. So, this looks like 130-year-old technology invented by Heinrich Hertz in 1886. near-field communication antenna,.
FM receiver antenna in the form of headphones cable. Three antennas in an old iPhone.
Almost the same number of antennas in my smartwatch. In the rear window of almost any car one can see an AM and FM antenna system integrated with the defogger heating elements. Several hundred antennas can be seen from my window: antennas in and on the cars in the parking lot, TV, satellite TV, antennas for amateur radio, cellular network antennas on high buildings.
I can see an antenna field consisting of four 1010 kHz medium wave (MW) tower antenna array of AM radio station CFRB Newstalk 1010 (Toronto) and one 6.07 MHz shortwave tower antenna of simulcast CFRX radio. Hawking Hi-Gain HWL2 Wi-Fi Locator 2.4 GHz 5 dBi antenna design.
Devices like this one were conveniently used to find Wi-Fi hotspots in the early 2000s, before the mass adoption of the smartphones. In total, I’ve got three dozen antennas in my apartment and several hundred can be seen from the window of my apartment. I cannot find some fresh language, therefore I will say that. Bruce faulconer ssj transformation. We are surrounded by antennas. So, let us talk about them in more detail.
We will try to do it without using any formulas so that it is clear even to those who do not like math! Webster’s Dictionary defines an antenna in radio and electronics as a metallic device, variously shaped, designed for the purpose of either transmitting or receiving radio waves. In other words, it is a device that converts the electric power of a transmitter into electromagnetic waves or electromagnetic waves into electric power to be amplified by a receiver. Most antennas operate efficiently only over a relatively narrow frequency band because they are resonant devices. To get a good reception or transmission, any antenna must be tuned to the frequency band of the radio transmitting or receiving system to which it is connected. At the end of the 19th century, there were only a few antennas in the world.
They were used to demonstrate transmission and receiving electromagnetic waves. 130 years later, in the 21st century, an average person carries several antennas in his pocket and has several dozen antennas in his home. Even refrigerators, stoves and ranges have Wi-Fi antennas nowadays!
Michael Faraday’s Laboratory at the Royal Institution in London Antenna History We should probably start telling the history of antennas, describing optical communications using smoke signals and acoustic communications using drums. The first experiments that involved electricity and magnetism together and showed the relationship between them were done by Michael Faraday in his laboratory now on display at the Royal Institution in London (pictured). The electronic communication started with the invention of the telegraph in the middle of the 19th century. Later, James Clerk Maxwell predicted the existence of electromagnetic waves. Maxwell’s theory was proved by the experiment of Heinrich Hertz who created the first dipole antennas and used them with reflectors to transmit radio waves with a frequency of about 450 MHz. Hertz also demonstrated polarization of radio waves using two perpendicular antennas. Marconi’s device for registration of the electromagnetic radiation (1900) on display at the Military Communications and Electronics Museum Kingston, Canada Marconi’s experiments conducted at the turn of the 20th century showed the possibility of wirelessly transmitting a signal across the Atlantic.
For this purpose, he used a 150-meter kite-supported antenna, which was approximately ¼ of the transmitted wavelength. It was a remarkable achievement because now we know that radio waves at this frequency (medium wave radio band) can propagate well during daytime only by means of the ground wave with a practical reception at the distance less than 300 to 400 km from the antenna. Greater distances can be achieved over salt water. In later Marconi’s tests, greater distances were achieved at night and he was the first to show that radio signals in the medium and long wave radio bands can travel much longer distances during the night than in the day.
Six rectangular sector antennas for cellular network communication and one backhaul link dish antenna on a high building. The sector antennas are usually built as a collinear array of phased dipoles consisting of vertically stacked dipoles spaced a wavelength apart with a reflective plate with all internal parts housed in a radome made of a material, which is transparent to radio waves. The sector antennas provide communication between cell phones and base stations. The sector antennas radiate horizontal fan-shaped beams, which are very narrow in the vertical plane.
The highly directional circular parabolic antennas enclosed in bass drum-like radomes, which protects them from dirt and snow, are used to transmit signals between ground stations. All antennas have a fundamental property called reciprocity. This property is a consequence of the reciprocity theorem of electromagnetism. In simple words, the reciprocity principle means that the gain or directivity pattern of an antenna will be the same whether it is transmitting or receiving electromagnetic waves. If, for example, a test signal is transmitted and the gain pattern is mapped out in the far field of the antenna, then the reciprocity principle tells that the receive gain pattern will be exactly the same. Main Characteristics of Antennas Antennas are characterized by several main performance measures, which define the antenna application. The main antenna characteristic is its power gain, which defines how well the antenna converts the input power into radio waves radiating in a specific direction (for a transmitting antenna) or how well the antenna converts radio waves arriving from a specific direction into electrical power (for a receiving antenna).
Other characteristics include antenna directivity, polarization, input impedance, resonant frequency, bandwidth and effective area. Because of the reciprocity principle, all antenna characteristics described below are the same whether the antenna is transmitting or receiving radio waves. Nowadays, even the street lights are equipped with antennas. They are used to remotely turn them on and off according to the local lighting conditions. Antenna power gain or simply gain is defined as the ratio of its radiation intensity in the direction of its peak radiation to that of an isotropic lossless antenna on condition that the power on the input of both antennas is equal. For example, a transmitting antenna gain of 13 dB means that the transmitting power measured in the antenna far field in the direction of its peak radiation will be 13 dB (or 20 times) higher than the power received from a lossless isotropic antenna with the same input power.
A receiving antenna with a power gain (or simply gain) of 13 dB would receive 13 dB more power in the direction of its peak radiation than a lossless isotropic antenna installed in the same place of the electromagnetic field. An omnidirectional TV antenna It is a well-established practice to indicate the gain with an additional letter after dB: dBi for the reference to the isotropic radiator and dBd for the reference to the half-wave dipole. More examples of absolute logarithmic units and quantities in decibels with suffixes and reference values can be found in the article. Do you always need a high-gain antenna? For example, if you receive relatively high signals in the rural area from several TV stations coming from several nearby cities, you will need an omnidirectional antenna (shown in the picture). If, however, you know the direction to the TV broadcast antenna and the TV signal in your place is relatively weak and is coming from only one direction, you will need a high-gain Yagi–Uda antenna.
The 3D radiation pattern of an ideal dipole antenna is a horn toroid (a doughnut without a hole). It shows that the radiation in the direction of the antenna axis is zero and has its maximum in the direction perpendicular to the dipole axis. The dipole antenna radiates equal power in all directions perpendicular to the dipole axis. Its radiation is gradually declined to zero on the dipole axis. Directivity and Radiation Pattern The antenna gain discussed above depends on its radiation pattern, which defines how much power is radiated by an antenna at various angles to its axis.
The picture shows an example of a 3D radiation pattern of a dipole antenna. It is common to picture the radiation pattern in just two planes: vertical and horizontal. If these two terms are used, it is assumed that the antenna is mounted in the orientation in which it will be used. For the pictured dipole antenna, the horizontal radiation pattern will be represented by a circle and the vertical pattern will look like an infinity symbol. The picture shows an ideal antenna. At the same time, the radiation pattern of the majority of antennas resembles many lobes in which the radiated signal strength reaches its maximum. The lobes are separated by “nulls”, that is, angles in which the radiation is zero.
The lobe with the maximum signal strength is called the main lobe and other lobes are called sidelobes. The sidelobe in the direction opposite to the main lobe is called the backlobe. AM/FM helical antenna installed on the car roof The antenna directivity factor is defined almost as its gain.
It is the ratio of the radiation intensity obtained in the main direction of radiation to the radiation intensity that would be generated by a lossless isotropic antenna with the same radiated power. It shows how well a particular antenna can concentrate the radiated or receiving energy. Unlike the directivity factor, the antenna gain takes into account its efficiency, which is always less than 100%. That is why gain is much more frequently used in the description of antenna characteristics. Since the early 1960s, the directivity pattern of high-frequency (HF) and very-high-frequency (VHF) large complex antennas in the far field are measured using a transmitter or a receiver towed behind an airplane or a helicopter.
Such systems are capable of measuring directivity patterns of very large phased array antennas. K u-band circular low-noise block downconverter (LNB) of a satellite TV parabolic dish antenna. 1 — LNB assembled; 2 — LNB with its plastic case removed; 3, 4 — the two probes orthogonal to each other (90 degrees apart) in the waveguide of the feedhorn receive the satellite radio signal collected by the antenna dish and carry them to the circuit board for amplification by a low-noise amplifier; 5 — LNB circuit board; 6 and 7 — the same probes projected into the waveguide; 8 — the back side of the circuit board with waveguide probes Polarization The polarization of an antenna is the orientation of its radiated electric field plane with respect to the Earth’s surface. It is determined by the physical structure of the antenna and its spatial orientation.
If an antenna is erected or installed vertically, its radiation is vertically polarized. If, however, an antenna is erected or installed horizontally, its radiation is horizontally polarized. There are also antennas with a cross and circular polarization. In circular polarization, the electric field vector is constantly rotating with circular motion about the direction of wave propagation in clockwise or anticlockwise direction. Consequently, the circular polarization can be right hand (RHCP) or left hand (LHCP).
The concept of polarization is very important for radio communication. A vertically polarized antenna will not receive a signal sent by a horizontally polarized antenna. AN/FPS-26 height-finder radar decommissioned in the mid-1970s. It was used in the Canadian Forces Station Ramore in Ontario. The station was a part of the Pinetree Line, which was a series of radar stations located across the United States and Canada designed to detect the Soviet bomber attack on North America. The antenna is on display at the Military Communications and Electronics Museum in Kingston, Ontario The impedance is a measure of the total opposition to the alternating current flow made up of two components: ohmic resistance and reactance, which, in turn, can be inductive or capacitive reactance. For an efficient transfer of energy, the impedances of a transmitter or receiver, antenna and the transmission line between them must be the same.
Receiving and transmitting equipment are often designed for the impedance of 50, 75 or 300 ohms. If there is a mismatch in the impedance, then losses will occur. To avoid such losses, impedance-matching devices such as baluns are used. A balun converts a balanced signal into an unbalanced one and vice versa.
A balun can include an impedance transformer and other devices. The word is an abbreviation from balanced– unbalanced. A reader who does not know the antenna technology will probably ask: why 50, 75 or 300? If to try to answer in simple words, then one can say that it happened historically. The fact is that this is the impedance of standard types of antennas. The resistance of a half-wave dipole is 75 ohms, that of a quarter-wave monopole with a ground plane is 50 ohms and that of a folded dipole is 300 ohms.
It was also convenient to make 75- and 50-ohms coaxial cables and 300-ohm ladder lines. VHF and UHF Yagi and monopole antennas of an amateur radio operator VA3EGG The consideration of impedance matching in antennas, transmission lines, receivers, and transmitters is important for minimizing losses. If the input impedance of an antenna does not match the output impedance of a transmitter, not only the antenna will radiate much less power, but the transmitter can be damaged. To connect the output stage of the transmitter to the coaxial cable that connects it to the antenna, often a matching device is required. If the condition of matching is not fully satisfied, then some power will be reflected back and this will lead to the creation of standing waves along the transmission line. The measure of impedance matching of loads to the impedance of a transmission line or a waveguide is the standing wave ratio (SWR). The standing wave ratio is often referred to as voltage standing wave ratio (VSWR) because the SWR is usually thought of in terms of AC minimum and maximum peak voltages of a standing wave along the transmission line.
VSWR = 1.0 means no power is reflected from the antenna and this is an ideal case. VSWR usually depends on frequency. To measure the standing wave ratio, SWR meters connected between the antenna and the transmission line are used. An aerostat of The Tethered Aerostat Radar System (TARS) operational site in Cudjoe Key, Florida. Flying at the altitude of about 4,600 m, it provides radar surveillance along the southwest border of the US and can detect low-level targets (like low-flying aircraft, but not cruise missiles). The L-88 radar installed in the aerostat and enclosed in the fabric radome provides 360-degree coverage at ranges up to 400 km.
The data from the aerostat radar are used by NORAD and US Customs and Border Protection Bandwidth The bandwidth of an antenna describes the range of frequencies within which the antenna can properly radiate or receive electromagnetic energy. When describing the bandwidth of an antenna, several parameters may serve as criteria. These are usually impedance match expressed in terms of VSWR (for example, VSWR. The cage dipole antenna array in the UTR-2 radio telescope. Due to the thickness of the dipole elements, their bandwidth is 8–33 MHz. This photo was taken in 1973 Antenna Classification Antennas are classified in various ways: according to their frequency range (MF, HF, VHF, UHF, etc.), according to their use (receiving, transmitting, radio communication, radio and television broadcasting, radio navigation, radiolocation, marine, aircraft, etc.), according to where they are used (ground, car, airborne, space, underwater). Often they are classified under common operating principles.
Because of lack of space, here we will only outline the classification:. Dipole antennas. Half-wave dipole (pictured). Yagi-Uda antenna (pictured). Cage dipole (pictured).
Log-periodic dipole array antenna. Turnstile antenna. Corner reflector antenna. Patch (microstrip, printed) antenna (pictured). Monopole antennas. Whip antenna (pictured).
Rubber ducky antenna (pictured). Ground plane antenna (pictured). Mast (tower) radiator (pictured).
Antennae Para Televisiones
T, inverted L and inverted F antennas. Antenna arrays. Three rectangular microwave slot antennas of marine radars. Their directional pattern resembles that of the vertical rectangular antennas of the cellular network shown in the picture above. The difference is that their beam is fan-shaped in the vertical plane and very narrow in the horizontal plane. The antennas scan 360° of azimuth about every two seconds. A slot antenna is often made from a waveguide, which contains many slots radiating electromagnetic waves similarly to dipole antennas.
Collinear array antenna (pictured). Reflective array antenna. Phased array antenna.
Curtain array antenna. Batwing or super turnstile. Microstrip array antenna. Loop antennas. Ferrite antenna.
Loop antenna. Quad antenna. Traveling wave antennas. Helical (pictured). Beverage antenna.
Rhombic. Aperture antennas. Parabolic dish antenna (pictured). Horn antenna (pictured).
Slot antenna (pictured). Dielectric lens antenna.
Hola buenos dias. A mi me hace falta una antena wifi potente para usar con wifislax y que pueda transmitir a una distancia considerable para usar linset de forma suculenta o por lo menos mejor que la antena de un ordenador portaril con i5. Seria para dentro de casa(para hacer auditorias), esta me sirve? Y si me convendria una omnidireccional, cual me recomiendas para que pueda usarse con wifislax sin ningun problema y cumpla algo de las especificaciones potenciales que mencione anteriormente y este en un rango de precio aceptable?
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