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Null (radio)
In radio electronics, a null is a direction in an antenna's radiation pattern where the antenna radiates almost no radio waves, so the far field signal strength is a local minimum. Nulls occur because different parts of an antenna radiate radio waves of different phase. In directions at which the antenna radiates equal amplitude radio waves of opposite phase, the radio waves cancel, resulting in little or no radio power being radiated in that direction. In other directions the radio waves from different parts of the antenna are in phase and reinforce, resulting in a maximum signal strength in the radiation pattern, called a lobe. In transmitting antennas designed to provide broad coverage nulls can be a problem, preventing reception in a given area. Null fill in the vertical plane is used to prevent this. Nulling antenna Nulls can also be used to advantage. In a radio receiver the receiver's antenna can be adjusted so the direction of the interference source is located in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sidelobes En
In antenna engineering, sidelobes are the lobes (local maxima) of the far field radiation pattern of an antenna or other radiation source, that are not the ''main lobe''. The radiation pattern of most antennas shows a pattern of "''lobes''" at various angles, directions where the radiated signal strength reaches a maximum, separated by "''nulls''", angles at which the radiated signal strength falls to zero. This can be viewed as the diffraction pattern of the antenna. In a directional antenna in which the objective is to emit the radio waves in one direction, the lobe in that direction is designed to have a larger field strength than the others; this is the "''main lobe''". The other lobes are called "''sidelobes''", and usually represent unwanted radiation in undesired directions. The sidelobe directly behind the main lobe is called the back lobe. The longer the antenna relative to the radio wavelength, the more lobes its radiation pattern has. In transmitting antennas, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toronto
Toronto ( ; or ) is the capital city of the Canadian province of Ontario. With a recorded population of 2,794,356 in 2021, it is the most populous city in Canada and the fourth most populous city in North America. The city is the anchor of the Golden Horseshoe, an urban agglomeration of 9,765,188 people (as of 2021) surrounding the western end of Lake Ontario, while the Greater Toronto Area proper had a 2021 population of 6,712,341. Toronto is an international centre of business, finance, arts, sports and culture, and is recognized as one of the most multicultural and cosmopolitan cities in the world. Indigenous peoples have travelled through and inhabited the Toronto area, located on a broad sloping plateau interspersed with rivers, deep ravines, and urban forest, for more than 10,000 years. After the broadly disputed Toronto Purchase, when the Mississauga surrendered the area to the British Crown, the British established the town of York in 1793 and later designat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Receiver
In radio communications, a radio receiver, also known as a receiver, a wireless, or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna. The antenna intercepts radio waves (electromagnetic waves of radio frequency) and converts them to tiny alternating currents which are applied to the receiver, and the receiver extracts the desired information. The receiver uses electronic filters to separate the desired radio frequency signal from all the other signals picked up by the antenna, an electronic amplifier to increase the power of the signal for further processing, and finally recovers the desired information through demodulation. Radio receivers are essential components of all systems that use radio. The information produced by the receiver may be in the form of sound, video (television), or digital data. A radio receiver may be a separate piece of electronic equipment, or an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Direction Finding
Direction finding (DF), or radio direction finding (RDF), isin accordance with International Telecommunication Union (ITU)defined as radio location that uses the reception of radio waves to determine the direction in which a radio station or an object is located. This can refer to radio or other forms of wireless communication, including radar signals detection and monitoring (ELINT/ESM). By combining the direction information from two or more suitably spaced receivers (or a single mobile receiver), the source of a transmission may be located via triangulation. Radio direction finding is used in the navigation of ships and aircraft, to locate emergency transmitters for search and rescue, for tracking wildlife, and to locate illegal or interfering transmitters. RDF was important in combating German threats during both the World War II Battle of Britain and the long running Battle of the Atlantic. In the former, the Air Ministry also used RDF to locate its own fighter group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detroit
Detroit ( , ; , ) is the largest city in the U.S. state of Michigan. It is also the largest U.S. city on the United States–Canada border, and the seat of government of Wayne County. The City of Detroit had a population of 639,111 at the 2020 census, making it the 27th-most populous city in the United States. The metropolitan area, known as Metro Detroit, is home to 4.3 million people, making it the second-largest in the Midwest after the Chicago metropolitan area, and the 14th-largest in the United States. Regarded as a major cultural center, Detroit is known for its contributions to music, art, architecture and design, in addition to its historical automotive background. ''Time'' named Detroit as one of the fifty World's Greatest Places of 2022 to explore. Detroit is a major port on the Detroit River, one of the four major straits that connect the Great Lakes system to the Saint Lawrence Seaway. The City of Detroit anchors the second-largest regional economy in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windsor, Ontario
Windsor is a city in southwestern Ontario, Canada, on the south bank of the Detroit River directly across from Detroit, Michigan, United States. Geographically located within but administratively independent of Essex County, it is the southernmost city in Canada and marks the southwestern end of the Quebec City–Windsor Corridor. The city's population was 229,660 at the 2021 census, making it the third-most populated city in Southwestern Ontario, after London and Kitchener. The Detroit–Windsor urban area is North America's most populous trans-border conurbation, and the Ambassador Bridge border crossing is the busiest commercial crossing on the Canada–United States border. Windsor is a major contributor to Canada's automotive industry and is culturally diverse. Known as the "Automotive Capital of Canada", Windsor's industrial and manufacturing heritage is responsible for how the city has developed through the years. History Early settlement At the time when the fir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wheatley, Ontario
Wheatley is a community in Southwestern Ontario, Canada, within the municipality of Chatham-Kent. It lies about east of Leamington. Nearby parks include Two Creeks Conservation Area, which has 15 km of hiking and bicycling paths, Kopegaron Woods Conservation Area, Hillman Marsh Conservation Area and Point Pelee National Park. Rondeau Provincial Park is only a forty-five-minute drive to the east. It also boasts Wheatley Provincial Park, home to the endangered Blue Racer snake, which can only be found in the park as well as the Point Pelee National Park and on Pelee Island. The town has a few beaches, including Camper's Cove Campsite and beach which lies on the former Highway 3. As well as Holiday Harbour Resort on Pier Road. The town's population in 2006 was 2,322. It is now 2,868, as of 2016. Wheatley is the primary community of licence for CHWI, a television station more popularly associated with the city of Windsor. Wheatley's sign proclaims it as the "Freshwater F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CIII-DT
CIII-DT (channel 41) is a television station in Toronto, Ontario, Canada, serving as the flagship station of the Global Television Network. Owned and operated by network parent Corus Entertainment, CIII-DT maintains studios at 81 Barber Greene Road (near Leslie Street) in the Don Mills district of Toronto, and its transmitter is located atop the CN Tower in downtown Toronto. The station reaches much of the population of Ontario through a network of 12 transmitters across primarily the southern and central portions of the province (as a result, it is the ''de facto'' Global outlet for the capital city of Ottawa through repeater CIII-DT-6). Since August 29, 2022, CIII-DT serves as the master control hub for all 15 Global owned-and-operated stations across Canada. History Ken Soble, the founder of CHCH-TV in Hamilton, envisioned a national " superstation" of 96 satellite-fed transmitters with CHCH as its flagship. In 1966, he filed the first application with the Board of Broad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Television Network
The Global Television Network (more commonly called Global, or occasionally Global TV) is a Canadian English-language terrestrial television network. It is currently Canada's second most-watched private terrestrial television network after CTV, and has fifteen owned-and-operated stations throughout the country. Global is owned by Corus Entertainment — the media holdings of JR Shaw and other members of his family. Global has its origins in a regional television station of the same name, serving Southern Ontario, which launched in 1974. The Ontario station was soon purchased by the now-defunct CanWest Global Communications, and that company gradually expanded its national reach in the subsequent decades through both acquisitions and new station launches, building up a quasi-network of independent stations, known as the CanWest Global System, until the stations were unified under the Ontario station's branding in 1997. History NTV The network has its origins in NTV, a new ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CIII-DT-22
CIII-DT (channel 41) is a television station in Toronto, Ontario, Canada, serving as the flagship station of the Global Television Network. Owned and operated by network parent Corus Entertainment, CIII-DT maintains studios at 81 Barber Greene Road (near Leslie Street) in the Don Mills district of Toronto, and its transmitter is located atop the CN Tower in downtown Toronto. The station reaches much of the population of Ontario through a network of 12 transmitters across primarily the southern and central portions of the province (as a result, it is the ''de facto'' Global outlet for the capital city of Ottawa through repeater CIII-DT-6). Since August 29, 2022, CIII-DT serves as the master control hub for all 15 Global owned-and-operated stations across Canada. History Ken Soble, the founder of CHCH-TV in Hamilton, envisioned a national "superstation" of 96 satellite-fed transmitters with CHCH as its flagship. In 1966, he filed the first application with the Board of Broadcast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, and received by another antenna connected to a radio receiver. Radio is very widely used in modern technology, in radio communication, radar, radio navigation, remote control, remote sensing, and other applications. In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking, and satellite communication, among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave by varying some aspect of the wave) in the transmitter. In radar, used to locate and track objects like aircraft, ships, spacecraf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertical Plane
In astronomy, geography, and related sciences and contexts, a '' direction'' or ''plane'' passing by a given point is said to be vertical if it contains the local gravity direction at that point. Conversely, a direction or plane is said to be horizontal if it is perpendicular to the vertical direction. In general, something that is vertical can be drawn from up to down (or down to up), such as the y-axis in the Cartesian coordinate system. Historical definition The word ''horizontal'' is derived from the Latin , which derives from the Greek , meaning 'separating' or 'marking a boundary'. The word ''vertical'' is derived from the late Latin ', which is from the same root as ''vertex'', meaning 'highest point' or more literally the 'turning point' such as in a whirlpool. Girard Desargues defined the vertical to be perpendicular to the horizon in his 1636 book ''Perspective''. Geophysical definition The plumb line and spirit level In physics, engineering and construction, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
