Antennas are electrical devices that will convert an electric power into a radio wave and vice versa. These are often used with radio transmitters or radio receivers. Antennas are the essential components for all the equipment that have radios. These are often used in broadcast television, communication receivers, cell phones, radio broadcasting, two way radio, radar, and satellite communication. It can also be used in some other devices such as wireless microphones, wireless computer networks, RFID tags, garage door openers, Bluetooth devices, baby monitors.
Mono pole is a type of antenna in which the militaries are making use of. The mono pole has one conductor only like a metal rod, mounted on artificial surfaces for conduction or above the grounds. The umbrella is a mono pole type that is usually being used by the militaries for their long range communications. The military antenna manufacturers have made a great contribution because of their productions since these antennas became so much useful to militaries.
An umbrella is a type which is a large wire that will transmit the antenna being used for the VLF band. It consists of mast radiator tower attached to its top with multiple wires which are extending in mast to ground, like tents and umbrellas. It is insulated in the ends. It also contains narrow bandwidth and requires counterpoise ground in low resistance and large loading coils.
Another type is array and its type that is utilized for military purposes, specifically for radar system and jamming system is the phased array. This is a higher gain antenna utilized for UHF and also for microwave frequencies that is steered electronically. It is consist of several dipoles in two dimensional arrays. Each dipole is fed through electric phase shifters that are being controlled by computer control systems.
One old type of antennas is a radio kite. This is utilized in carrying radios to an aloft, which is higher than a practical mast. Usually, the kite is associated with portable systems for radios and for an increased range of radio in the naval ships. Using this type has limitations because of difficulties for maintaining its height, the wind is unpredictable, and improvements for reception, antenna, and transmission.
When installing an antenna, it is important to consider its effects on the ground. Factors to consider are height, electrical properties, permittivity, and the conductivity. Particularly, in mono pole antennas, grounds serve as a return connection of the current and this is the reason for the effects.
For the low frequencies to high frequencies, the grounds behave as the lossy dialectrics. And thus, these will be characterized by the permittivity and conductivity. For a lower frequency, it acts as good conductor.
If the frequency is between 3 to 30 megahertz, a very large portion of energy from the horizontally polarized antennas will reflect on it. While the vertically polarized one will not be well reflected except for the grazing incidence. However, the reflection of grazing angles is in phase with direct waves.
The reflections net quality depends on its surface topography. If some surface irregularities may happen to be smaller than wavelengths, there is specular reflection. But if it is bigger than wavelengths, reflection is being shifted by random phases.
Mono pole is a type of antenna in which the militaries are making use of. The mono pole has one conductor only like a metal rod, mounted on artificial surfaces for conduction or above the grounds. The umbrella is a mono pole type that is usually being used by the militaries for their long range communications. The military antenna manufacturers have made a great contribution because of their productions since these antennas became so much useful to militaries.
An umbrella is a type which is a large wire that will transmit the antenna being used for the VLF band. It consists of mast radiator tower attached to its top with multiple wires which are extending in mast to ground, like tents and umbrellas. It is insulated in the ends. It also contains narrow bandwidth and requires counterpoise ground in low resistance and large loading coils.
Another type is array and its type that is utilized for military purposes, specifically for radar system and jamming system is the phased array. This is a higher gain antenna utilized for UHF and also for microwave frequencies that is steered electronically. It is consist of several dipoles in two dimensional arrays. Each dipole is fed through electric phase shifters that are being controlled by computer control systems.
One old type of antennas is a radio kite. This is utilized in carrying radios to an aloft, which is higher than a practical mast. Usually, the kite is associated with portable systems for radios and for an increased range of radio in the naval ships. Using this type has limitations because of difficulties for maintaining its height, the wind is unpredictable, and improvements for reception, antenna, and transmission.
When installing an antenna, it is important to consider its effects on the ground. Factors to consider are height, electrical properties, permittivity, and the conductivity. Particularly, in mono pole antennas, grounds serve as a return connection of the current and this is the reason for the effects.
For the low frequencies to high frequencies, the grounds behave as the lossy dialectrics. And thus, these will be characterized by the permittivity and conductivity. For a lower frequency, it acts as good conductor.
If the frequency is between 3 to 30 megahertz, a very large portion of energy from the horizontally polarized antennas will reflect on it. While the vertically polarized one will not be well reflected except for the grazing incidence. However, the reflection of grazing angles is in phase with direct waves.
The reflections net quality depends on its surface topography. If some surface irregularities may happen to be smaller than wavelengths, there is specular reflection. But if it is bigger than wavelengths, reflection is being shifted by random phases.
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