12-09-2015, 01:57 PM
i want arunkumar notes for microwaves and rador notes.
|
arun kumar notes of microwaves and radar
|
i want arunkumar notes for microwaves and rador notes.
17-03-2017, 11:05 AM
Microwaves are a form of electromagnetic radiation with wavelengths ranging from one meter to one millimeter; With frequencies between 300 MHz (100 cm) and 300 GHz (0.1 cm). Different sources define different frequency ranges such as microwaves; The above broad definition includes UHF and EHF (millimeter wave) bands. A more common definition in radio engineering is the range between 1 and 100 GHz (300 and 3 mm). In all cases, microwaves include the entire SHF band (3 to 30 GHz, or 10 to 1 cm) as a minimum. Frequencies in the microwave range are often referred to by their IEEE radar band designations: S, C, X, Ku, K or Ka band, or by similar NATO or EU designations. The micro- prefix in microwaves is not intended to suggest a wavelength in the micrometer range. It indicates that microwaves are "small", compared to the waves used in typical radio broadcasting, in that they have shorter wavelengths. The boundaries between far infrared, terahertz radiation, microwaves and ultra-high-frequency radio waves are quite arbitrary and are used in varying ways between different fields of study.
Microwaves travel by line of sight; Unlike low-frequency radio waves, they do not diffract around the hills, follow the surface of the earth as earthwaves or reflect from the ionosphere, so that terrestrial microwave communication links are limited by the visual horizon 64 km. At the upper end of the band are absorbed by gases in the atmosphere, limiting the practical distances of communication to about a kilometer. Microwaves are very widely used in modern technology. They are used for point-to-point communication links, wireless networks, microwave radiofrequency networks, radar, satellite and spacecraft communications, medical diathermy and cancer treatment, remote sensing, radio astronomy, particle accelerators, spectroscopy, Collisions, garage door openers and keyless entry systems, and to cook food in microwave ovens.
Radar is an object detection system that uses radio waves to determine the range, angle, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations and terrain. A radar system consists of a transmitter that produces electromagnetic waves in the radio or microwave domain, a transmitting antenna, a receiving antenna (often the same antenna is used to transmit and receive) and a receiver and processor to determine the properties of the objects) . The radio waves (pulsed or continuous) of the transmitter reflect the object and return to the receiver, giving information on the location and speed of the object. The radar was secretly developed for military use by several nations in the period before and during World War II. The term RADAR was coined in 1940 by the United States Navy as an acronym for RAdio Detection And Ranging or RAdio Direction And Ranging. The term radar has since entered English and other languages as a common noun, losing all the capital letters.
Modern uses of radar are very diverse, including air and ground traffic control, radar astronomy, air defense systems, anti-missile systems, marine radars to locate signals and other ships, aircraft collision systems, ocean surveillance systems, Surveillance systems and encounter systems, meteorological precipitation monitoring, altimetry and flight control systems, guided missile targeting systems, ground penetration radar for geological observations, and scope control radar for public health surveillance. High-tech radar systems are associated with digital signal processing, automatic learning and are able to extract useful information from very high noise levels.
|
« Next Oldest | Next Newest »
|
