Antenna (radio)In radio engineering, an antenna (American English) or aerial (British English) is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver. In transmission, a radio transmitter supplies an electric current to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic waves (radio waves). In reception, an antenna intercepts some of the power of a radio wave in order to produce an electric current at its terminals, that is applied to a receiver to be amplified.
Antenna arrayAn antenna array (or array antenna) is a set of multiple connected antennas which work together as a single antenna, to transmit or receive radio waves. The individual antennas (called elements) are usually connected to a single receiver or transmitter by feedlines that feed the power to the elements in a specific phase relationship. The radio waves radiated by each individual antenna combine and superpose, adding together (interfering constructively) to enhance the power radiated in desired directions, and cancelling (interfering destructively) to reduce the power radiated in other directions.
Dipole antennaIn radio and telecommunications a dipole antenna or doublet is the simplest and most widely used class of antenna. The dipole is any one of a class of antennas producing a radiation pattern approximating that of an elementary electric dipole with a radiating structure supporting a line current so energized that the current has only one node at each end. A dipole antenna commonly consists of two identical conductive elements such as metal wires or rods.
EuropeEurope is a continent comprising the westernmost peninsulas of Eurasia, located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It shares the continental landmass of Afro-Eurasia with both Africa and Asia. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east. Europe is commonly considered to be separated from Asia by the watershed of the Ural Mountains, the Ural River, the Caspian Sea, the Greater Caucasus, the Black Sea and the waterways of the Turkish Straits.
Aperture (antenna)In electromagnetics and antenna theory, the aperture of an antenna is defined as "A surface, near or on an antenna, on which it is convenient to make assumptions regarding the field values for the purpose of computing fields at external points. The aperture is often taken as that portion of a plane surface near the antenna, perpendicular to the direction of maximum radiation, through which the major part of the radiation passes.
Smart antennaSmart antennas (also known as adaptive array antennas, digital antenna arrays, multiple antennas and, recently, MIMO) are antenna arrays with smart signal processing algorithms used to identify spatial signal signatures such as the direction of arrival (DOA) of the signal, and use them to calculate beamforming vectors which are used to track and locate the antenna beam on the mobile/target. Smart antennas should not be confused with reconfigurable antennas, which have similar capabilities but are single element antennas and not antenna arrays.
Eastern EuropeEastern Europe is a subregion of the European continent. As a largely ambiguous term, it has a wide range of geopolitical, geographical, ethnic, cultural, and socio-economic connotations. The region stretches from the Ural Mountains in the east to the borders of Poland and Romania. Most definitions include the countries of Belarus, Russia, and Ukraine while less restrictive definitions also include Bulgaria, the Czech Republic, Hungary, Moldova, Poland, Romania, and Slovakia.
Unit testingIn computer programming, unit testing is a software testing method by which individual units of source code—sets of one or more computer program modules together with associated control data, usage procedures, and operating procedures—are tested to determine whether they are fit for use. It is a standard step in development and implementation approaches such as Agile. Before unit testing, capture and replay testing tools were the norm. In 1997, Kent Beck and Erich Gamma developed and released JUnit, a unit test framework that became popular with Java developers.
Northwestern EuropeNorthwestern Europe, or Northwest Europe, is a loosely defined subregion of Europe, overlapping Northern and Western Europe. The term is used in geographic, history, and military contexts. Geographically, Northwestern Europe is given by some sources as a region which includes Great Britain, Ireland, Belgium, the Netherlands, Luxembourg, Northern France, parts of Germany, Denmark, Norway, Sweden, and Iceland. In some works, Switzerland, Finland, and Austria are also included as part of Northwestern Europe.
Western EuropeWestern Europe is the western region of Europe. The region's extent varies depending on context. The concept of "the West" appeared in Europe in juxtaposition to "the East" and originally applied to the ancient Mediterranean world, the Roman Empire (Western Roman Empire and Eastern Roman Empire), and medieval "Christendom" (Western Christianity and Eastern Christianity). Beginning with the Renaissance and the Age of Discovery, roughly from the 15th century, the concept of Europe as "the West" slowly became distinguished from and eventually replaced the dominant use of "Christendom" as the preferred endonym within the region.
Television antennaA television antenna (TV aerial) is an antenna specifically designed for use with a television receiver (TV) to receive over-the-air broadcast television signals from a television station. Television reception is dependent upon the antenna as well as the transmitter. Terrestrial television is broadcast on frequencies from about 47 to 250 MHz in the very high frequency (VHF) band, and 470 to 960 MHz in the ultra high frequency (UHF) band in different countries.
Southern EuropeSouthern Europe is the southern region of Europe. It is also known as Mediterranean Europe, as its geography is marked by the Mediterranean Sea. Definitions of Southern Europe include some or all of these countries and regions: Albania, Andorra, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Turkey (East Thrace), Gibraltar, Greece, Italy, Kosovo, Malta, Monaco, Montenegro, North Macedonia, Portugal, San Marino, Serbia, Slovenia, Southern France, Spain, and Vatican City.
Parabolic antennaA parabolic antenna is an antenna that uses a parabolic reflector, a curved surface with the cross-sectional shape of a parabola, to direct the radio waves. The most common form is shaped like a dish and is popularly called a dish antenna or parabolic dish. The main advantage of a parabolic antenna is that it has high directivity. It functions similarly to a searchlight or flashlight reflector to direct radio waves in a narrow beam, or receive radio waves from one particular direction only.
Software testingSoftware testing is the act of examining the artifacts and the behavior of the software under test by validation and verification. Software testing can also provide an objective, independent view of the software to allow the business to appreciate and understand the risks of software implementation. Test techniques include, but are not necessarily limited to: analyzing the product requirements for completeness and correctness in various contexts like industry perspective, business perspective, feasibility and viability of implementation, usability, performance, security, infrastructure considerations, etc.
Acceptance testingIn engineering and its various subdisciplines, acceptance testing is a test conducted to determine if the requirements of a specification or contract are met. It may involve chemical tests, physical tests, or performance tests. In systems engineering, it may involve black-box testing performed on a system (for example: a piece of software, lots of manufactured mechanical parts, or batches of chemical products) prior to its delivery.
Phased arrayIn antenna theory, a phased array usually means an electronically scanned array, a computer-controlled array of antennas which creates a beam of radio waves that can be electronically steered to point in different directions without moving the antennas. In a simple array antenna, the radio frequency current from the transmitter is fed to multiple individual antenna elements with the proper phase relationship so that the radio waves from the separate elements combine (superpose) to form beams, to increase power radiated in desired directions and suppress radiation in undesired directions.
Free softwareFree software or libre software or libreware is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, not price; all users are legally free to do what they want with their copies of a free software (including profiting from them) regardless of how much is paid to obtain the program.
Yagi–Uda antennaA Yagi–Uda antenna, or simply Yagi antenna, is a directional antenna consisting of two or more parallel resonant antenna elements in an end-fire array; these elements are most often metal rods acting as half-wave dipoles. Yagi–Uda antennas consist of a single driven element connected to a radio transmitter and/or receiver through a transmission line, and additional "passive radiators" with no electrical connection, usually including one so-called reflector and any number of directors.
Languages of EuropeMost languages of Europe belong to the Indo-European language family. Out of a total European population of 744 million as of 2018, some 94% are native speakers of an Indo-European language. Within Indo-European, the three largest phyla in Europe are Romance, Germanic, and Slavic; they have more than 200 million speakers each and together account for close to 90% of Europeans.
Integration testingIntegration testing (sometimes called integration and testing, abbreviated I&T) is the phase in software testing in which the whole software module is tested or if it consists of multiple software modules they are combined and then tested as a group. Integration testing is conducted to evaluate the compliance of a system or component with specified functional requirements. It occurs after unit testing and before system testing.
