Feb 03, · A microwave antenna is designed to receive and transmit electromagnetic radiation with wavelengths between infrared radiation and radio waves. Microwave radiation can travel through the atmosphere or space; the antennas pick up those signals in broadband, a specified band, or single frequency. The technology comes in many sizes and shapes, linking voice and data wireless . Jul 08, · A microwave antenna is a transmission device used to transmit microwave transmissions from one location to another. Antennas are commonly used in electronics, radar, and radio astronomy. Microwave antennas are commonly used for radar, radio, and satellite communications as well as wireless communication systems.
A communication system is a system that transfers data between equipment and persons. A microwave antenna is defined as a device for physical transmission and is used for broadcasting microwave transmissions between two or more places. Microwave waht are important elements for any microwave network. Most types of microwave antennas are designed specifically to meet various mechanical and electrical requirements.
Every type of microwave antenna has features that enable it to function in specific situations and systems. The microstrip patch antenna has a patch used for radiating js that connects to a ground plane on one of its parts and a dielectric substrate on the opposite side.
Generally, the patch antenna contains conducting metals such as gold and copper. Patch antenna types have an operational frequency ranging between MHz and GHz. These antennas can be produced in huge amounts due to some benefits such as low fabrication cost, low volume, and less weight.
The antennas are popular for their extent of usage and good performance. Some of the areas where patch antennas are applied include paging devices, personal communication systems, cellular phones, and global positing satellites.
A horn antenna is comprised of a waveguide, which has flared end walls on the outside forming a structure what is a microwave antenna looks like a megaphone. The wwhat are used widely as antennas what the cause of diabetes frequencies above MHz and ultra-high frequencies. Horn antennas are used to approximate how much gain the other antennas have.
They are used as directive and calibrating antennas for equipment such as microwave-radio meters, and automatic door openers. Some of the benefits of horn antennas are broad bandwidth, low-standing wave ratio, and moderate directivity. Horn antennas have a gain ranging up to 25db. They are used extensively at microwave frequency when you require moderate power gain. This antenna uses a parabolic reflector.
This is a parabolic-shaped and curved area that is used to direct the radio waves. The antenna is shaped like a dish thus it is referred to as a parabolic dish or dish antenna.
One of the benefits of a parabolic antenna is that it has high directivity. Parabolic antennas are applied as radio telescopes and for point-to-point communication since they have high-end gain. Also, these antennas are microwaave as radars. They require the transmission of a narrow beam wave of radio to some equipment such as q and ships. This is a kind how to address wedding invitations plus one radio antenna that uses plasma anhenna than metal elements as a development device.
Metal elements were used in antennas in the past years. Plasma antenna uses ionized gas for conduction. The gas is ionized when reception or transmission occurs. The plasma antenna can operate up to 90GHz frequency range. Thus, they can be applied in reception and transmission of signals from radios. Besides, the antenna has a cutoff of high frequency. Some of the areas where plasma antennas are applied include 4G and radar systems, RFID, electronic intelligence, and high-speed digital communications.
MIMO is an abbreviation for multiple inputs and multiple outputs. MIMO antennas are applied in radio. They are used at the receiving and transmitting points to enhance the process of communication. MIMO antenna is among the best technologies in smart antenna. There are two ways of exploiting multiple antennas in MIMO. One, they are used in creating highly effective antenna directivity.
They are also used in the transmission of parallel data streams. These antennas receive and radiate energy in all horizontal directions equally. Omnidirectional antennas offer a perfect solution for applications that need good all-around coverage. In what is a microwave antenna applications, the antennas can be used to accommodate a specific down tilt to achieve a near field coverage.
These designs are made specifically to stabilize and align the antenna automatically. At the same time, they maintain the point to point path in the movement of a platform in unstable surroundings. Tracking antenna is routinely used in aviation, offshore drilling, marine, and mobile platforms. Here, the operators depend on Line-of-Sight LoS communications. This is a versatile antenna that utilizes a driven element. Behind the driven element is a reflector while in front of it is a director or several directors.
What should you invest in right now design of the yagi antenna mcrowave significant as it is easy to optimize for features such as bandwidth, front-to-back ratio, and gain using the available modern antenna design software. Some of the antenna designs use a corner reflector at the back of the driven element to enhance performance. Yagi antennas are easy to construct. This is only when there is available material. These antennas are used in various airborne platforms as radio navigation and communication systems.
Airborne amtenna are designed for use in difficult surroundings for years of optimum efficiency and trouble-free operation. The systems are used in an array of custom frequency bands, military, scientific, and standard commercial bands. These antennas are used as part of how many rupees to pound data link system for communications on aircraft.
The microwave antennas described above are useful devices in radar, radio, and satellite communications and also in wireless communication systems. Different microwave antennas have different uses. Each characteristic of the microwave antennas makes them suitable for specific situations and systems. It is important to familiarize yourself with this knowledge so as understand the aantenna system. Visit our blog for more information about microwave antennas and their uses.
Jan 18, · A horn antenna, sometimes called a microwave horn, is basically a flared waveguide feed which has a shape that resembles a horn. This horn shape provides a transition between waveguide feed and the launch into free space at the horn opening. The signal is launched in the waveguide portion of the horn using a short probe. Keeping microwave antennas in the eye of the storm High winds and inclement weather pose a challenge for communications infrastructure in general, and microwave antennas in particular. Operators often experience trouble with paths due to misaligned. Jun 02, · An antenna pattern, or radiation pattern, is a 2D (or 3D contour) plot which shows the angular variation in an antenna parameter such as the relative field strength in the far-field. The pattern is usually presented in polar coordinates and with a dB scale. An example of 2D antenna .
Microwave transmission is the transmission of information by microwave radio waves. Although an experimental mile 64 km microwave telecommunication link across the English Channel was demonstrated in , the development of radar in World War II provided the technology for practical exploitation of microwave communication.
In the s, large transcontinental microwave relay networks, consisting of chains of repeater stations linked by line-of-sight beams of microwaves were built in Europe and America to relay long distance telephone traffic and television programs between cities.
Communication satellites which transferred data between ground stations by microwaves took over much long distance traffic in the s. In recent years, there has been an explosive increase in use of the microwave spectrum by new telecommunication technologies such as wireless networks , and direct-broadcast satellites which broadcast television and radio directly into consumers' homes.
Microwaves are widely used for point-to-point communications because their small wavelength allows conveniently-sized antennas to direct them in narrow beams, which can be pointed directly at the receiving antenna. This allows nearby microwave equipment to use the same frequencies without interfering with each other, as lower frequency radio waves do.
This frequency reuse conserves scarce radio spectrum bandwidth. Another advantage is that the high frequency of microwaves gives the microwave band a very large information-carrying capacity; the microwave band has a bandwidth 30 times that of all the rest of the radio spectrum below it.
A disadvantage is that microwaves are limited to line of sight propagation; they cannot pass around hills or mountains as lower frequency radio waves can. Microwave radio transmission is commonly used in point-to-point communication systems on the surface of the Earth, in satellite communications , and in deep space radio communications. Other parts of the microwave radio band are used for radars , radio navigation systems, sensor systems, and radio astronomy.
The next higher frequency band of the radio spectrum , between 30 GHz and GHz, are called " millimeter waves " because their wavelengths range from 10 mm to 1 mm. Radio waves in this band are strongly attenuated by the gases of the atmosphere. This limits their practical transmission distance to a few kilometers, so these frequencies cannot be used for long distance communication.
The electronic technologies needed in the millimeter wave band are also in an earlier state of development than those of the microwave band. More recently, microwaves have been used for wireless power transmission. Microwave radio relay is a technology widely used in the s and s for transmitting information, such as long-distance telephone calls and television programs between two terrestrial points on a narrow beam of microwaves. In microwave radio relay, a microwave transmitter and directional antenna transmits a narrow beam of microwaves carrying many channels of information on a line of sight path to another relay station where it is received by a directional antenna and receiver, forming a fixed radio connection between the two points.
The link was often bidirectional, using a transmitter and receiver at each end to transmit data in both directions.
The requirement of a line of sight limits the separation between stations to the visual horizon, about 30 to 50 miles 48 to 80 km. For longer distances, the receiving station could function as a relay, retransmitting the received information to another station along its journey. Chains of microwave relay stations were used to transmit telecommunication signals over transcontinental distances. Microwave relay stations were often located on tall buildings and mountaintops, with their antennas on towers to get maximum range.
The launch of communication satellites in the s provided a cheaper Much of the transcontinental traffic is now carried by satellites and optical fibers , but microwave relay remains important for shorter distances. Because the radio waves travel in narrow beams confined to a line-of-sight path from one antenna to the other, they do not interfere with other microwave equipment, so nearby microwave links can use the same frequencies.
Antennas must be highly directional high gain ; these antennas are installed in elevated locations such as large radio towers in order to be able to transmit across long distances. Typical types of antenna used in radio relay link installations are parabolic antennas , dielectric lens, and horn-reflector antennas , which have a diameter of up to 4 meters. Highly directive antennas permit an economical use of the available frequency spectrum, despite long transmission distances.
Because of the high frequencies used, a line-of-sight path between the stations is required. Additionally, in order to avoid attenuation of the beam, an area around the beam called the first Fresnel zone must be free from obstacles.
Obstacles in the signal field cause unwanted attenuation. High mountain peak or ridge positions are often ideal. Obstacles, the curvature of the Earth, the geography of the area and reception issues arising from the use of nearby land such as in manufacturing and forestry are important issues to consider when planning radio links.
In the planning process, it is essential that "path profiles" are produced, which provide information about the terrain and Fresnel zones affecting the transmission path.
The presence of a water surface, such as a lake or river, along the path also must be taken into consideration since it can reflect the beam, and the direct and reflected beam can interfere at the receiving antenna, causing multipath fading. Rare events of temperature, humidity and pressure profile versus height, may produce large deviations and distortion of the propagation and affect transmission quality.
High-intensity rain and snow making rain fade must also be considered as an impairment factor, especially at frequencies above 10 GHz. All previous factors, collectively known as path loss , make it necessary to compute suitable power margins, in order to maintain the link operative for a high percentage of time, like the standard The longest microwave radio relay known up to date crosses the Red Sea with a km mi hop between Jebel Erba m a.
The link was built in by Telettra to transmit telephone channels and one TV signal, in the 2 GHz frequency band. Hop distance is the distance between two microwave stations.
Previous considerations represent typical problems characterizing terrestrial radio links using microwaves for the so-called backbone networks: hop lengths of a few tens of kilometers typically 10 to 60 km were largely used until the s. Frequency bands below 10 GHz, and above all, the information to be transmitted, were a stream containing a fixed capacity block. During s microwave radio links begun widely to be used for urban links in cellular network.
Requirements regarding link distance changed to shorter hops less than 10 km, typically 3 to 5 km , and frequency increased to bands between 11 and 43 GHz and more recently, up to 86 GHz E-band.
Furthermore, link planning deals more with intense rainfall and less with multipath, so diversity schemes became less used. Another big change that occurred during the last decade was an evolution toward packet radio transmission.
Therefore, new countermeasures, such as adaptive modulation , have been adopted. The emitted power is regulated for cellular and microwave systems. These microwave transmissions use emitted power typically from 0. In the last decade the dedicated spectrum for each microwave band has become extremely crowded, motivating the use of techniques to increase transmission capacity such as frequency reuse, Polarization-division multiplexing , XPIC , MIMO.
The first experiments with radio repeater stations to relay radio signals were done in by Emile Guarini-Foresio. The need for radio relay did not really begin until the s exploitation of microwaves , which traveled by line of sight and so were limited to a propagation distance of about 40 miles 64 km by the visual horizon. In an Anglo-French consortium headed by Andre C.
Clavier demonstrated an experimental microwave relay link across the English Channel using foot 3 m dishes. The radiated power, produced by a miniature Barkhausen-Kurz tube located at the dish's focus, was one-half watt. A military microwave link between airports at St. Inglevert, France, and Lympne, UK, a distance of 56 km 35 miles , was followed in by a MHz telecommunication link, the first commercial microwave relay system.
The development of radar during World War II provided much of the microwave technology which made practical microwave communication links possible, particularly the klystron oscillator and techniques of designing parabolic antennas.
After the war, telephone companies used this technology to build large microwave radio relay networks to carry long distance telephone calls. It was expected at that time that the annual operating costs for microwave radio would be greater than for cable. There were two main reasons that a large capacity had to be introduced suddenly: Pent up demand for long distance telephone service, because of the hiatus during the war years, and the new medium of television, which needed more bandwidth than radio.
Remarkable were the microwave relay links to West Berlin during the Cold War , which had to be built and operated due to the large distance between West Germany and Berlin at the edge of the technical feasibility. In addition to the telephone network, also microwave relay links for the distribution of TV and radio broadcasts. This included connections from the studios to the broadcasting systems distributed across the country, as well as between the radio stations, for example for program exchange.
Military microwave relay systems continued to be used into the s, when many of these systems were supplanted with tropospheric scatter or communication satellite systems.
When the NATO military arm was formed, much of this existing equipment was transferred to communications groups. The typical communications systems used by NATO during that time period consisted of the technologies which had been developed for use by the telephone carrier entities in host countries.
The typical microwave relay installation or portable van had two radio systems plus backup connecting two line of sight sites. These radios would often carry 24 telephone channels frequency division multiplexed on the microwave carrier i. Lenkurt 33C FDM. Any channel could be designated to carry up to 18 teletype communications instead. Similar systems from Germany and other member nations were also in use. Long-distance microwave relay networks were built in many countries until the s, when the technology lost its share of fixed operation to newer technologies such as fiber-optic cable and communication satellites , which offer a lower cost per bit.
By positioning a geosynchronous satellite in the path of the beam, the microwave beam can be received. At the turn of the century, microwave radio relay systems are being used increasingly in portable radio applications. The technology is particularly suited to this application because of lower operating costs, a more efficient infrastructure , and provision of direct hardware access to the portable radio operator.
A microwave link is a communications system that uses a beam of radio waves in the microwave frequency range to transmit video , audio , or data between two locations, which can be from just a few feet or meters to several miles or kilometers apart.
Microwave links are commonly used by television broadcasters to transmit programmes across a country, for instance, or from an outside broadcast back to a studio. Mobile units can be camera mounted, allowing cameras the freedom to move around without trailing cables. These are often seen on the touchlines of sports fields on Steadicam systems. Terrestrial microwave relay links are limited in distance to the visual horizon , a few tens of miles or kilometers depending on tower height.
Tropospheric scatter "troposcatter" or "scatter" was a technology developed in the s to allow microwave communication links beyond the horizon, to a range of several hundred kilometers.
The transmitter radiates a beam of microwaves into the sky, at a shallow angle above the horizon toward the receiver. As the beam passes through the troposphere a small fraction of the microwave energy is scattered back toward the ground by water vapor and dust in the air. A sensitive receiver beyond the horizon picks up this reflected signal.
Signal clarity obtained by this method depends on the weather and other factors, and as a result, a high level of technical difficulty is involved in the creation of a reliable over horizon radio relay link. Troposcatter links are therefore only used in special circumstances where satellites and other long-distance communication channels cannot be relied on, such as in military communications. From Wikipedia, the free encyclopedia. This article needs additional citations for verification.
Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Listen to this article 5 minutes. This audio file was created from a revision of this article dated 22 September , and does not reflect subsequent edits. Energy portal Telecommunication portal. The Tube Guys. Russ Cochran. ISBN