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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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sidelobes En
In antenna (radio), antenna engineering, sidelobes are the lobes (local maxima) of the Near and far field, 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 "''null (radio), nulls''", angles at which the radiated signal strength falls to zero. This can be viewed as the diffraction, 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 ... [...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 Television in Canada, Canadian English language, English-language terrestrial television, terrestrial television network. It is currently Canada's second most-watched private terrestrial television network after CTV Television Network, 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 CIII-DT, 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, 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 unifie ... [...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 based on radio technology. 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 equ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Direction Finding
Direction finding (DF), radio direction finding (RDF), or radiogoniometry is the use of radio waves to determine the direction to a radio source. The source may be a cooperating radio transmitter or may be an inadvertent source, a naturally-occurring radio source, or an illicit or enemy system. Radio direction finding differs from radar in that only the direction is determined by any one receiver; a radar system usually also gives a distance to the object of interest, as well as direction. By triangulation, the location of a radio source can be determined by measuring its direction from two or more locations. Radio direction finding is used in radio navigation for ships and aircraft, to locate emergency transmitters for search and rescue, for tracking wildlife, and to locate illegal or interfering transmitters. During the Second World War, radio direction finding was used by both sides to locate and direct aircraft, surface ships, and submarines. RDF systems can be used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tower Array
A tower array is an arrangement of multiple radio towers which are mast radiators in a phased array. They were originally developed as ground-based tracking radars. Tower arrays can consist of free-standing or guyed towers or a mix of them. Tower arrays are used to constitute a directional antenna of a mediumwave or longwave radio station. The number of towers in a tower array can vary. In many arrays all towers have the same height, but there are also arrays of towers of different height. The arrangement can vary. For directional antennas with fixed radiation pattern, linear arrangements are preferred, while for switchable directional patterns (usually for daytime groundwave versus nighttime skywave), square arrangements are chosen. Examples Tower arrays with guyed masts * Longwave transmitter Europe 1 * Transmitter Weisskirchen * Beidweiler Longwave Transmitter * Transmitter Wachenbrunn * Transmitter Ismaning (VoA-Station) Tower arrays with free-standing towers * Junglins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Directional Antenna
A directional antenna or beam antenna is an antenna that radiates or receives greater radio wave power in specific directions. Directional antennas can radiate radio waves in beams, when greater concentration of radiation in a certain direction is desired, or in receiving antennas receive radio waves from one specific direction only. This can increase the power transmitted to receivers in that direction, or reduce interference from unwanted sources. This contrasts with omnidirectional antennas such as dipole antennas which radiate radio waves over a wide angle, or receive from a wide angle. The extent to which an antenna's angular distribution of radiated power, its radiation pattern, is concentrated in one direction is measured by a parameter called antenna gain. A high-gain antenna (HGA) is a directional antenna with a focused, narrow beam width, permitting more precise targeting of the radio signals. Most commonly referred to during space missions, these antennas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medium Wave
Medium wave (MW) is a part of the medium frequency (MF) radio band used mainly for AM radio broadcasting. The spectrum provides about 120 channels with more limited sound quality than FM stations on the FM broadcast band. During the daytime, reception is usually limited to more local stations, though this is dependent on the signal conditions and quality of radio receiver used. Improved signal propagation at night allows the reception of much longer distance signals (within a range of about 2,000 km or 1,200 miles). This can cause increased interference because on most channels multiple transmitters operate simultaneously worldwide. In addition, amplitude modulation (AM) is often more prone to interference by various electronic devices, especially power supplies and computers. Strong transmitters cover larger areas than on the FM broadcast band but require more energy and longer antennas. Digital modes are possible but had not yet reached momentum. MW was the main radio b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detroit
Detroit ( , ) is the List of municipalities in Michigan, most populous city in the U.S. state of Michigan. It is situated on the bank of the Detroit River across from Windsor, Ontario. It had a population of 639,111 at the 2020 United States census, 2020 census, making it the List of United States cities by population, 26th-most populous city in the United States and the largest U.S. city on the Canada–United States border. The Metro Detroit area, home to 4.3 million people, is the second-largest in the Midwestern United States, Midwest after the Chicago metropolitan area and the 14th-largest in the United States. The county seat, seat of Wayne County, Michigan, Wayne County, Detroit is a significant cultural center known for its contributions to music, art, architecture and design, in addition to its historical automotive and industrial background. In 1701, Kingdom of France, Royal French explorers Antoine de la Mothe Cadillac and Alphonse de Tonty founded Fort Pontc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windsor, Ontario
Windsor ( ) is a city in southwestern Ontario, Canada. It is situated on the south bank of the Detroit River directly across from the U.S city of Detroit, Detroit, Michigan. Geographically located within but administratively independent of Essex County, Ontario, 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 Canadian Census, 2021 census, making it the third-most populated city in Southwestern Ontario, after London, Ontario, London and Kitchener, Ontario, Kitchener. This represents a 5.7 percent increase from Windsor's 2016 population census of 217,188. The Detroit–Windsor urban area is North America's most populous trans-border conurbation. Linking the Great Lakes Megalopolis, the Ambassador Bridge border crossing is the busiest commercial crossing on the Canada–United States border, carrying about one-quarter of the two countries' trade volume. Windsor ... [...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 was 2,322 in 2006. As of 2016, the population was 2,868. 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 ... [...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 Broadcas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toronto
Toronto ( , locally pronounced or ) is the List of the largest municipalities in Canada by population, most populous city in Canada. It is the capital city of the Provinces and territories of Canada, Canadian province of Ontario. With a population of 2,794,356 in 2021, it is the List of North American cities by population, 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. As of 2024, the census metropolitan area had an estimated population of 7,106,379. Toronto is an international centre of business, finance, arts, sports, and culture, and is recognized as one of the most multiculturalism, multicultural and cosmopolitanism, cosmopolitan cities in the world. Indigenous peoples in Canada, Indigenous peoples have travelled through and inhabited the Toronto area, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
