|
FHSS
Frequency-hopping spread spectrum (FHSS) is a method of transmitting radio signals by rapidly changing the carrier frequency among many frequencies occupying a large spectral band. The changes are controlled by a code known to both transmitter and receiver. FHSS is used to avoid interference, to prevent eavesdropping, and to enable code-division multiple access (CDMA) communications. The frequency band is divided into smaller sub-bands. Signals rapidly change ("hop") their carrier frequencies among the center frequencies of these sub-bands in a determined order. Interference at a specific frequency will affect the signal only during a short interval. FHSS offers four main advantages over a fixed-frequency transmission: # FHSS signals are highly resistant to narrowband interference because the signal hops to a different frequency band. # Signals are difficult to intercept if the frequency-hopping pattern is not known. # Jamming is also difficult if the pattern is unknown; the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spread Spectrum
In telecommunications, especially radio communication, spread spectrum are techniques by which a signal (electrical engineering), signal (e.g., an electrical, electromagnetic, or acoustic) generated with a particular Bandwidth (signal processing), bandwidth is deliberately spread in the frequency domain over a wider frequency band. Spread-spectrum techniques are used for the establishment of secure communications, increasing resistance to natural Interference (communication), interference, Noise (electronics), noise, and radio jamming, jamming, to prevent detection, to limit Spectral flux density, power flux density (e.g., in satellite downlinks), and to enable multiple-access communications. Telecommunications Spread spectrum generally makes use of a sequential noise-like signal structure to spread the normally narrowband information signal over a relatively wideband (radio) band of frequencies. The receiver correlates the received signals to retrieve the original information ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Link-16
Link 16 is a military tactical data link network used by NATO members and other nations, as allowed by the Multifunctional Information Distribution System, MIDS International Program Office (IPO). Its Technical standard, specification is part of the family of Tactical Data Links. Link 16 enables military aircraft, ships, and ground forces to exchange their tactical picture in near-real time; it also supports the exchange of text messages, imagery, and voice (the latter on two digital channels: 2.4 kbit/s or 16 kbit/s in any combination). It is one of the digital services of the JTIDS / Multifunctional Information Distribution System, MIDS in NATO's ''Standardization Agreement'' STANAG 5516. MIL-STD-6016 is the related United States Department of Defense Link 16 MIL-STD. Technical characteristics Link 16 is a Time-division multiple access, TDMA-based security, secure, jam-resistant, high-speed digital data link that operates in the radio frequency band 960–1,215 He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmitter
In electronics and telecommunications, a radio transmitter or just transmitter (often abbreviated as XMTR or TX in technical documents) is an electronic device which produces radio waves with an antenna (radio), antenna with the purpose of signal transmission to a radio receiver. The transmitter itself generates a radio frequency alternating current, which is applied to the Antenna (radio), antenna. When excited by this alternating current, the antenna Electromagnetic radiation, radiates radio waves. Transmitters are necessary component parts of all electronic devices that communicate by radio communication, radio, such as radio broadcasting, radio (audio) and television broadcasting stations, cell phones, walkie-talkies, Wireless LAN, wireless computer networks, Bluetooth enabled devices, garage door openers, two-way radios in aircraft, ships, spacecraft, radar sets and navigational beacons. The term ''transmitter'' is usually limited to equipment that generates radio waves fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guglielmo Marconi
Guglielmo Giovanni Maria Marconi, 1st Marquess of Marconi ( ; ; 25 April 1874 – 20 July 1937) was an Italian electrical engineer, inventor, and politician known for his creation of a practical radio wave-based Wireless telegraphy, wireless telegraph system. This led to Marconi being credited as the inventor of radio and sharing the 1909 Nobel Prize in Physics with Karl Ferdinand Braun "in recognition of their contributions to the development of wireless telegraphy". His work laid the foundation for the development of radio, television, and all modern wireless communication systems. Marconi was also an entrepreneur and businessman who founded the Wireless Telegraph & Signal Company (which became the Marconi Company) in the United Kingdom of Great Britain and Ireland, United Kingdom in 1897. In 1929, Marconi was ennobled as a marchese, marquess (''marchese'') by Victor Emmanuel III. In 1931, he set up Vatican Radio for Pope Pius XI. Biography Early years Guglielmo Giovanni Mar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks in World War II, Tanks and Air warfare of World War II, aircraft played major roles, enabling the strategic bombing of cities and delivery of the Atomic bombings of Hiroshima and Nagasaki, first and only nuclear weapons ever used in war. World War II is the List of wars by death toll, deadliest conflict in history, causing World War II casualties, the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Allied-occupied Germany, Germany, Allied-occupied Austria, Austria, Occupation of Japan, Japan, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polish Zloty
Polish may refer to: * Anything from or related to Poland, a country in Europe * Polish language * Polish people, people from Poland or of Polish descent * Polish chicken * Polish brothers (Mark Polish and Michael Polish, born 1970), American twin screenwriters * Kevin Polish, an American Paralympian archer Polish may refer to: * Polishing, the process of creating a smooth and shiny surface by rubbing or chemical action ** French polishing, polishing wood to a high gloss finish * Nail polish * Shoe polish * Polish (screenwriting), improving a script in smaller ways than in a rewrite See also * * * Polishchuk (surname) * Polonaise (other) A polonaise ()) is a stately dance of Polish origin or a piece of music for this dance. Polonaise may also refer to: * Polonaises (Chopin), compositions by Frédéric Chopin ** Polonaise in A-flat major, Op. 53 (, ''Heroic Polonaise''; ) * Polon ... {{Disambiguation, surname Language and nationality disambiguation pages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polish General Staff
Polish General Staff, formally known as the General Staff of the Polish Armed Forces ( Polish: ''Sztab Generalny Wojska Polskiego'') is the highest professional body within the Polish Armed Forces. Organizationally, it is an integral part of the Ministry of National Defence and the Chief of the General Staff is the highest ranking military officer at the Ministry. It was created in 1918, and was renamed the Main Staff (''Sztab Główny'') in 1928 before being reverted back to General Staff (''Sztab Generalny'') in 1945 by the Soviet backed Communist Government. Currently General Wiesław Kukuła holds the position of Chief of the General Staff of the Polish Armed Forces (''Szef Sztabu Generalnego Wojska Polskiego''). History and structure On 25 October 1918, a decision was made to establish the directorate of the chief of staff of the Polish Army. On 22 December 1928 the General Staff was renamed to the Main Staff (''Sztab Główny''). In September 1939, during the Invasion of Pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leonard Danilewicz
Leonard Stanisław Danilewicz was a Polish engineer and, for some ten years before the outbreak of World War II, one of the four directors of the AVA Radio Company in Warsaw, Poland. Cipher Bureau work AVA designed and built radio equipment for the Polish General Staff's Cipher Bureau, which was responsible for the radio communications of the General Staff's ''Oddział II'' (Section II, the General Staff's intelligence section). Beginning in 1933, after the Cipher Bureau's mathematician- cryptologist Marian Rejewski reconstructed the German military Enigma rotor cipher machine, AVA built Enigma "doubles" as well as all the electro-mechanical equipment subsequently designed at the Cipher Bureau to expedite routine breaking and reading of Enigma ciphers. AVA's other directors were Edward Fokczyński, Antoni Palluth, and Leonard Danilewicz's elder brother, Ludomir Danilewicz. The company took its name from the combined radio callsigns of the Danilewicz brothers (''TPAV'') an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polish People
Polish people, or Poles, are a West Slavic ethnic group and nation who share a common History of Poland, history, Culture of Poland, culture, the Polish language and are identified with the country of Poland in Central Europe. The preamble to the Constitution of the Republic of Poland defines the Polish nation as comprising all the citizenship, citizens of Poland, regardless of heritage or ethnicity. The majority of Poles adhere to Roman Catholicism. The population of self-declared Poles in Poland is estimated at 37,394,000 out of an overall population of 38,512,000 (based on the 2011 census), of whom 36,522,000 declared Polish alone. A wide-ranging Polish diaspora (the ''Polish diaspora, Polonia'') exists throughout Eurasia, the Americas, and Australasia. Today, the largest urban concentrations of Poles are within the Warsaw metropolitan area and the Katowice urban area. Ethnic Poles are considered to be the descendants of the ancient West Slavic Lechites and other tribes t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War I
World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting took place mainly in European theatre of World War I, Europe and the Middle Eastern theatre of World War I, Middle East, as well as in parts of African theatre of World War I, Africa and the Asian and Pacific theatre of World War I, Asia-Pacific, and in Europe was characterised by trench warfare; the widespread use of Artillery of World War I, artillery, machine guns, and Chemical weapons in World War I, chemical weapons (gas); and the introductions of Tanks in World War I, tanks and Aviation in World War I, aircraft. World War I was one of the List of wars by death toll, deadliest conflicts in history, resulting in an estimated World War I casualties, 10 million military dead and more than 20 million wounded, plus some 10 million civilian de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EE Times
''EE Times'' (''Electronic Engineering Times'') is an electronics industry magazine published in the United States since 1972. EE Times is currently owned by AspenCore, a division of Arrow Electronics since August 2016. Ownership and status ''EE Times'' was launched in 1972 by Gerard G. Leeds of CMP Publications Inc. In 1999, the Leeds family sold CMP to United Business Media for $900 million. After 2000, ''EE Times'' moved more into web publishing. The shift in advertising from print to online began to accelerate in 2007, and the periodical shed staff to adjust to the downturn in revenue. In July 2013, the digital edition migrated to UBM TechWeb's DeusM community platform. On June 3, 2016, UBM announced that ''EE Times'', along with the rest of its electronics media portfolio ( EDN, Embedded.com, TechOnline, and Datasheets.com), was being sold to AspenCore Media, a company owned by Arrow Electronics, for $23.5 million. The acquisition was completed on August 1, 2016. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telefunken
Telefunken was a German radio and television producer, founded in Berlin in 1903 as a joint venture between Siemens & Halske and the ''AEG (German company), Allgemeine Elektrizitäts-Gesellschaft'' (AEG) ("General electricity company"). Prior to World War I, the company set up the first world-wide network of communications and was the first in the world to sell electronic televisions with cathode-ray tubes, in Germany in 1934. The brand had several incarnations: * ''Gesellschaft für drahtlose Telegraphie Gesellschaft mit beschränkter Haftung, m.b.H., System Telefunken'', founded in 1903 as a joint venture between AEG and Siemens & Halske * ''Telefunken, Gesellschaft für drahtlose Telegraphie m.b.H.'', in 1923; since 1941 as subsidiary of AEG alone * ''Telefunken Gesellschaft mit beschränkter Haftung, GmbH'', in 1955 * ''Telefunken Aktiengesellschaft (AG)'', in 1963 * ''Allgemeine Elektrizitäts-Gesellschaft AEG-Telefunken'', created in 1967 through a merger between Telefunken ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
