Satellite Antenna or Parabolic Dishes: Characteristics, Types and Much More

Satellite or satellite dishes are tools that translate into a power to boost social, technological or economic development throughout the universe. It is a very useful resource in terms of information transmission, among other contributions that we will disaggregate.

Satellite or satellite dishes

What are satellite dishes or satellite dishes?

We walk on any street or avenue and see frequently on the roofs of houses or on the top of buildings and also on small hills in urban areas, giant plates such as aluminum of all sizes, and even with other equipment incorporated into they making them even more extravagant.

In addition to this, towers with links and pieces of many meters high installed on the roof part of the buildings, connected with cables are also achieved. But many times, like any episode of everyday life, we completely ignore the existence or reason of such devices.

We have asked ourselves; What are satellite or satellite dishes for? What is their name really beyond antenna? What is its scope? We begin with the term antenna in the first place to break down the subject and know in depth everything related to the differences and their importance.

Satellite dishes and their meaning

Satellite or satellite dishes; In the simplest term they are devices of very different forms that, in the emitters and receivers of electromagnetic waves, are used to emit or receive them.

In other terms used by telecommunications experts, or wave reception or simply in a radio transmitter system, an antenna is an element that has the mission of throwing into the space the electromagnetic energy supplied by a generator and driven by an appropriate transmission line.

In a receiving system it is intended to collect the energy of the waves that come from the surrounding space and send it, always through a convenient line, to the appropriate apparatus.

Antennas

In both cases, the antenna functions as a link between two media, space and the transmission line, in which electromagnetic waves propagate following different laws. That is, the antenna constitutes an adapter between two systems; line and space.

Meaning of Transmission

We will pause to explain what the term transmission consists of. We have that it is the action of sending a message, that is, communicating a news or broadcasting a radio and television station, music programs, shows, etc.

Experts in this area explain that transmission allows driving or being the means through which vibrations or radiations pass.

Antennas and transmission

Continuing with the theme of the antennas, in its most characteristic form it is presented as a metal structure equipped with two input terminals, through which it feeds. For any given antenna, the magnitudes that characterize its way of functioning can be defined.

Radiation diagrams, directivity, gain, impedance, bandwidth or bandwidth are vitally important, that is, the frequency range for which the best performance and polarization is obtained.

Impedance

In physics, this term is used to identify the total apparent resistance of a circuit to the passage of an alternating current. It is measured in ohms.

Impedance in the antennas

Bandwidth of satellite or satellite dishes

As for the bandwidth, this refers to the absolute energy of an amplifier or any quadrupole, is given by the separation between the two frequencies for which the amplification is less than the maximum in three decibels; The frequency field between these values ​​is called the pass band and the two frequencies that limit it are the cutoff frequencies.

In addition, the absolute bandwidth can be defined as a relative bandwidth, given by the relationship between the absolute bandwidth and the center band frequency, defined as the square root of the product of the two cutoff frequencies.

Authors who started satellite dishes or satellite dishes

We will begin with a beginning beyond the idea, with the German physicist Heinrich Rudolf Hertz who discovered the low frequency electromagnetic waves, called in his honor hertzian waves. He showed that they are subject to the same laws of reflection and refraction as the luminous ones and measured their speed, the same as those of light and infrared radiation.

In this way he confirmed the electromagnetic nature of light and the electromagnetic theory of Maxwel, giving way to the development of radio wireless telegraphy. He also discovered the phenomenon known as photoelectric effect, whereby light and other forms of high frequency electromagnetic energy cause the emission of electrons in some metals.

"Hertz

In his honor he gave the name of hertz to the frequency unit. Between his works they emphasize Principles of the mechanics and On the relations between the light and the electricity.

Among those who ventured into this issue of waves, broadcasting, and everything related to satellite dishes or components and components was also Isaac Newton, however, his studies took another approach for certain results with his experiments that apparently were not what they expected with respect to the initial idea.

However, it is important to describe about this author in mathematics discovered at the same time as libniz, the calculation of fluxions, and generalized the formula of the binomial demonstrating that it was applicable to any speaker.

Isaac newtom

Mathematically demonstrated that the course of the planets around the Sun is explained by admitting mutual attraction between the stars, which generalized all kinds of masses, which are attracted, according to the famous Law of universal gravitation.

He also determined with great accuracy the masses of the sun and the planets and several of the particularities of the movement of Planet Earth. Similarly, among his discoveries based on prolonged research, he showed that the tides are due to the attraction of the sun and the moon, calculated various cometary orbits, etc. (See article: How does the moon affect the tides?)

Isaac entered the world of waves

On the other hand, in the history of the principles of satellite or satellite dishes there is also James Clerk Maxwel, a British physicist and mathematician who investigated almost all fields of physics: he said that Saturn's rings are made up of small isolated masses.

He determined that electromagnetic waves propagate with the speed of light, which led him to affirm that this was also a form of electromagnetic energy.

Maxwel

After these intellectual authors who dabbled in the interesting world that began to emerge in relation to electromagnetic waves, were for example Grote Reber, who advanced an important step in technology with the development of radio astronomy with the construction of a radio telescope.

Such a structure included the shape of a parabolic mirror that allowed it to demonstrate the existence of an exorbitant amount of very low energy signals, while Marconi Guglielmo, who used the parabolic reflectors to transmit UHF by sea.

Marconi, From an early age he became interested in Hertz's discoveries about wave transmission and in 1895 he managed to make wireless telegraphy transmissions; the following year he founded the Marconi Wireless Telegraphy Company, and in 1899 the signals were transmitted through the English Channel.

Guglielmo and its contributions for the construction of antennas and satellites

In December 1901, wireless communication was established between Europe and America. Thanks to his discoveries, very rapid progress was made in all media with ships on the high seas and in many other directions. In 1909 he received the Nobel Prize in Physics.

Satellite or satellite dishes: What is directivity?

The directivity of an antenna is the relationship between the intensity of the radiated bonnet in the direction of maximum radiation and that of the field irradiated by a hypothetical antenna with a spherical diagram, with equal irradiated power. The more pronounced the main lobe of an antenna, the greater its directivity.

The radiation pattern of an antenna that radiates equally in all directions (isotropic antenna) would be a sphere with its center in the center of the antenna, but such an antenna is of impossible physical realization.

"directivity

What is a parable?

A parabola is the conic that is obtained as a geometric place of the equidistant points of a fixed line MN (director) and a fixed point F (focus); It is also the intersection line determined by a conical surface and a plane parallel to a generatrix.

Every parabola can be represented by an equation of the form y² = 2px (equation of the parabola in canonical form) where p is a constant (parameter of the parabola). A material point thrown with a certain initial velocity in a uniform force field describes a parabola arc.
parable arch

Since the gravitational field is uniform, as long as it is considered a region not too large, it can be said that the trajectory of a projectile in a vacuum is an arc of parabola. The name of parabola also designates other curves represented by equations of the type y = axª (parabola of order n) with a = constant.

Satellite or satellite dish antennas

The word radar is an acronym for the English name Radio detecting and Ranging, which covers all electronic systems capable of detecting the presence of obstacles, locating them and determining their distance to the observation post.

These systems are based on the properties of electromagnetic waves that, when they reach a target endowed with sufficient electrical conductivity, are partially reflected in it. Guglielmo Marconi sensed the possibility of detecting the presence of moving objects through the modifications caused by them in the characteristics of the radio waves that reach them.

In 1922, Taylor and Young, in the USA, picking up Marconi's ideas, managed to detect the presence of a ship. Breit and I had, in 1925, by means of an impulse procedure, managed to determine the height of the ionosphere. These studies were resumed in 1930, based on the method of continuous wave interference that allows only to notice the presence of an obstacle.

From then on it began to be presumed that this would be possible by resorting to methods in which higher frequencies than usual were necessary, if only to reduce the importance of the necessary antennas.

In 1936, a pulse radar operating at 200 MHz began operating in the US. Between 1939 and 1941, several ships in the US squad were equipped with radar. At the same time, the main European nations began to take an interest in radar: France, Germany and especially England, which found a great filmmaker in Sir Robert Watson.

Decisive importance for progress

The effectiveness of the radar was increasing until it became a factor of decisive warlike importance when the technique managed to dominate the microwave field, thanks to the research and two fundamental inventions: the magnetron and the Klystron, two microwave power generating tuvos.

From a technological point of view, every radar consists of a transmitter and a receiver. Depending on the type of modulation chosen there are: unmodulated continuous wave radar (Doppler effect), frequency modulated continuous wave radar and pulse radar.

radar antenna

Just as in the radio communications at the receiver's output the signals act on the speaker or other device that replaces it, on the radar they act on a device, called an indicator, variable according to the types of radar, whose structure depends on the kind of representation of information about the position, speed or other similar data related to the obstacle.

In Doppler radars, a frequency wave F affects the object with a velocity v (in the direction of wave propagation) and is reflected with a frequency f '= f + 2v / c, different from the previous one (c is wave propagation speed).

The frequency f 'is higher af if the reflective surface approaches the transmitter. This effect can be used by a continuous wave radar for the detection of objects equipped with radial movement with respect to the radar, and for the measurement of that speed, comparing with the radar receiver the frequencies f and f'and deduce, by the batting, its difference 2v / c.

radar antenna

This frequency is sent to an acoustic detector or to a suitable frequency meter. Knowing c, v can be calculated. The frequency meter itself is usually graduated so that it directly supplies the reading v.

The frequency modulated radar is based on the emission of a continuous signal that, modulated in frequency and reflected in the obstacle, returns to the starting point with a delay Λt. If the frequency modulation is obtained by a sinusoidal modulation of frequency f, as is generally the case, the corresponding phase difference between the output and arrival modulations is Λφ = 2π · Λt.

As for the pulse radar, it is the most common and is based on the irradiation, by means of directional antennas and more or less wide area scanners of the horizon, of radiofrequency waves modulated to impulses, that is, with a modulation of the all or nothing.

This radar allows the detection of many obstacles, even in different directions, always within the radiation beam of the antennas.

In most cases, the antenna is unique and is used for both transmission and reception; in the antenna power line, it is necessary to exchange a switching device, called TR-anti TR that prevents strong radiofrequency output pulses from damaging the receiver's input circuit.

The delay in the arrival of the reflected impulse, with respect to the output, analogically to what was said above, and starting the same notations, Λt = 2D-c. To avoid ambiguities in the determination of distances, it must be less than the repetition period with which the radiofrequency impulses occur.

Radar antenna

The duration of each pulse influences the minimum range of the radar and its resolving power, or the minimum distance at which two different obstacles must be found in order to be distinguished by the radar.

IMPORTANT UTILITY OF SATELLITE DISHES OR RADAR SATELLITES

Both features improve by decreasing the pulse duration. In satellite dish or satellite sighting antennas, the repetition period is usually given a value of 1000 μsec and each pulse has a duration of 1 μsec. Thus, 100 kw pulses of power correspond to an average radiofrequency power of 100 watts.

Similar to what happens with the frequency modulation radar, the distance rating is calculated by multiplying Λt by half the speed of light.

Radar

In order to locate the obstacles located in the area of ​​considerable amplitude, it is necessary that the antenna can carry out certain movements, the whole of which constitutes the exploration. The various obstacles appear at successive times, depending on the antenna positions.

The most common modalities of exploration, which must be carried out automatically, are circular, helical, conical and spiral.

In circular exploration, the antenna rotates continuously around its axis, generally vertical, with constant angular velocity over the entire horizon, or with alternative movements within angles below 360 °.

The speed of rotation of the antenna must be regulated so that the pulses that reach a certain target during a rotation are not too scarce to obtain a correct representation of said target.

For the exploration of these parabolic or satellite antennas, an antenna with a narrow irradiation diagram and rotation symmetry is needed. During movement, the main lobe of this diagram describes a spherical propeller around the vertical axis.

helical type antennas

If the opening of the irradiation beam is b, it is varied at the height of the b / 2 antenna during the time it takes to effect a complete revolution in a horizontal direction. The exploded helical belt has an equal overlap ab / 2, which constitutes an adequate safety margin for the discovery of the target.

Also the conical scan requires an antenna with a narrow irradiation diagram. The axis of the main irradiation lobe and therefore the antenna describes a circular conical opening surface equal to the semi-coverage of said lobe.

If the target is located on the axis of the cone, all the impulses it receives have the same intensity, whatever the position of the irradiation lobe with respect to said cone. For this reason, the cone axis is called the direction of the equiseñal.

Helical type antennas

Minimum revelable power. A signal present at the exit of the radar receiver contains, not only the echo power received, but also disturbances due, first of all to causes of industrial origin and to discharges from the atmosphere that affect the low frequencies little; secondly, the existing radiations in the atmosphere and finally fluctuations in the intensity and voltage of the electric component current.

In order to increase the sensitivity of the receivers and therefore the radar range, very sensitive amplifiers, such as the maser, have been built, with which extremely low noise factors are achieved. In the following graph we see what a maser is, what they call the cousin of lightning, which will potentially revolutionize technology. Later we will describe it.

maser

The radar range also accuses all phenomena related to the propagation of electromagnetic waves. The reflections produced on the ground reach the obstacle, not only the direct wave, but also those coming from these reflections.

The result of both invests in reaching the obstacle more time than the direct wave would need, thus producing a gap between the two. The greater path traveled by the reflected wave also implies its greater absorption by the terrain.

The effects of atmospheric refraction and terrestrial curvature on the propagation of radio waves can be deduced from the geometric relationship between the shape of the curve actually traveled and what it would have if the radius of curvature of the earth's surface became infinite and the Earth It could be considered flat.

Radar

With respect to traditional transmitting and receiving devices, the impulse-type radar devices, considered below, have a greater degree of differentiation.

  • Receivers So that the impulses can be reconstructed with the minimum possible deformation, after passing through the detector, it is necessary that the operating band in the radar receiver is much larger than in normal receivers. For the usual radars, bands a = 2/3 MHz are required for values ​​of about 30 MHz of the average frequency.
  • Transmitters In pulse modulation, which is of the all or nothing type, the radiofrequency power takes its maximum value or null value, following the rate of the modulating pulses. The frequency of radio frequency can be generated by a power tube driven by an oscillating tube or by a chain of steps.

transmitters

The small tactical land use radars, fundamentally fulfill the mission of saving the necessary deployment of units to monitor the large spaces imposed by the atomic war and the insidious insights that characterize those of guerrillas.

An example of this type of radar is the French Rasura, which is installed in a light vehicle or portable version, consisting of three elements of 20 kg each, and detects moving bodies at 10 km if it is a vehicle and 7 km In the case of a man.

Another variety of radars in full development are those mounted on aircraft for observation of the terrain that fly over for purposes of surveillance and location of objects or navigation, to make possible the low-level flight, that is, flush with the cups of the trees, in order to avoid the detection of enemy radars.

shave radar

This special type of radar is called Terrain following in English. The signals it provides about terrain accidents and obstacles automatically pass to the airplane controls that, without pilot intervention, avoid them.

DEFINITION OF MASER

A maser is a device similar to laser, to produce and amplify microwaves by induced emission of radiation. It is based on the principle that molecules and atoms can exist at two or more energy levels and that, when moving from a high level to a lower level, emit electromagnetic waves that act as amplifiers of extraordinary sensitivity.

Charles townes

In the previous graph, the American physicist named Charles Hard Townes is shown. In the early fifties, regardless of Basov and Projorov, he devised the principle of the maser, that is, the microwave amplifier by stimulated emission of radiation. The idea had already been advanced by Einstein, but it had not been implemented.

In 1953, applying this principle, he built the first maser in history, which produced the alteration of molecules and in turn generated energy in measures smaller than those of a watt.

In collaboration with another scientist named Schawlow, he showed that it was also possible to build a similar device, which in microwave flirting, generated light waves that he called a laser or light amplification by stimulated emission of radiation.

Among his work, the physicist also investigated the application of the maser in radio astronomy, that is, in the case of studies using artificial satellites and astronomy , as well as leading programs that allowed the location of molecules in outer space , specifically in stellar dust, which then threw the discovery of water in some celestial spheres. See article: Planets with water .)

Porgreso

With all these characteristics that we have talked about so far about the different types of radars, we see that each one has a function, some with different characteristics but others with similar aspects, according to the elements considered in its construction.

Regarding the uses or purposes, we explain in the beginning that this type of tools is positioned as one of the most important elements for the development of a nation, region or locality, considering that in the communicational part and the transmission of information and data keeps globalization up to date by the different events that are presented.

importance of antennas

In other aspects, the antennas allow the collection of data to keep the populations informed to the minute, for example televisions in other languages, diverse programming, families from one country to another could maintain contact immediately, and in other cases it also influences The security part.

At this point, the important assessment given to satellite or satellite dishes is high considering the level of well-being that a nation's government grants its citizens, such as a type of radar antenna, which is installed with the intention of locating elements that could be considered enemies and that break the security and order,

The investments made by the institutions, organizations and governments of each nation are quite high precisely so as not to skimp on expenses when it comes to complying with the protocol security part established in the statutes.

Antennas to protect the nation

Always these types of devices are in total operability and functionality, regardless of the presence of enemy intervention in the area, the evolution of technology must constantly make its appearance and seek methods for the advances of the new ages to intercede Positive way for use with greater optimization.

SATELLITE OR SATELLITE DISHES

As for satellite or satellite dishes, they are instruments that serve in many phases of scientific research applicable to various sectors to promote evolution and progress, which cover a large amount of data.

For example, we can distinguish those of civil order, with projections for future commercial or military uses, which in turn promote the collection of photographic material from the environment, warnings of possible offensive actions, direct war threats, etc.

Satellite antenna

SATELLITE DISHES OR FLAT-TYPE SATELLITES

This type of satellite dishes or flat-type satellites are also called planar matrix, and they have to be constructed with light, simple and very practical pieces with the mission of making them as little as possible, both sight and space.

They have been the most compact satellite reception antennas that are designed for the convenience of users and their optimization will depend on their situation with respect to the area of ​​the footprint area of ​​the satellite coverage that has been selected.

However, the negative part of the use of this type of satellite dishes or flat-type satellites, is that their elements do not allow the choice of several satellites for the fulfillment of their objectives, that is, the flat antennas are limited to using only one satelite.

Flat antennas

However, they turn out to be quite discreet but with a lot of power, which can be installations on the balconies of apartments, on the terraces of houses or buildings, which also allows adjusting to the aesthetic and protocol structure of living in residences, avoiding attracting attention and complying with the rules also.

Those who designed this type of discrete antennas, also made it possible to have outputs for the distribution of the signal to be captured by more than one receiver, and in addition to this, these models can be incorporated into panels or decorated to conceal them even more than strange or ill-intentioned looks. Or simply shelter them.

SATELLITE OR SATELLITE DISHES FOR CELL PHONES

As for this type of satellite dish or cell phone antennas, it can be added that it is linked to telecommunications and a specific sector that affects a link that benefits a large part of a nation.

For example, speaking of sectors, we specify certain services provided by the security forces, the fire department, clinics and hospitals and other networks that merit the use of both mobile and fixed telephony such as companies, schools or residential areas.

We know that mobile telephony is one of the fundamental pillars in the era of telecommunications, and once they began to emerge thanks to the discoveries of scientists and researchers along with these needs, technologies evolved and are now much more advanced and avant-garde by the current requirement that globalization has established and society has been marking and demanding.

The antennas come to form the root or matrix of all these aspects of importance and according to the mathematical and geometric particularities for their elaboration, there are three types or categories of antennas that are linear, flat and volumetric.

cell phone antennas

Cellular telephony is given by the functioning of the cells, which allows the user to keep moving and communicating, and the theory is that the greater the number of cells, the better the signal a person receives on his phone to communicate.

Previously, according to the history of satellite dishes or telephony antennas, towers with a lot of height were used or built frequently for that purpose, pedestal, self-supporting, braced, monopole, among others, but currently and with the studies at par of the evolutions in technology have been reduced to antennas, much more comfortable and practical.

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