id stringlengths 24 24 | title stringclasses 442
values | context stringlengths 151 3.71k | question stringlengths 12 270 | answers dict |
|---|---|---|---|---|
572f0de1dfa6aa1500f8d59e | Antenna_(radio) | Both the vertical and dipole antennas are simple in construction and relatively inexpensive. The dipole antenna, which is the basis for most antenna designs, is a balanced component, with equal but opposite voltages and currents applied at its two terminals through a balanced transmission line (or to a coaxial transmis... | What is used to close the circuit of a dipole antenna? | {
"answer_start": [
619
],
"text": [
"large conductive surface"
]
} |
572f3f63947a6a140053c816 | Antenna_(radio) | Antennas more complex than the dipole or vertical designs are usually intended to increase the directivity and consequently the gain of the antenna. This can be accomplished in many different ways leading to a plethora of antenna designs. The vast majority of designs are fed with a balanced line (unlike a monopole ante... | What are different designs aimed at increasing? | {
"answer_start": [
128
],
"text": [
"gain of the antenna"
]
} |
572f3f63947a6a140053c817 | Antenna_(radio) | Antennas more complex than the dipole or vertical designs are usually intended to increase the directivity and consequently the gain of the antenna. This can be accomplished in many different ways leading to a plethora of antenna designs. The vast majority of designs are fed with a balanced line (unlike a monopole ante... | What is different from a monopole antenna with most other antenna types? | {
"answer_start": [
283
],
"text": [
"balanced line"
]
} |
572f3f63947a6a140053c818 | Antenna_(radio) | Antennas more complex than the dipole or vertical designs are usually intended to increase the directivity and consequently the gain of the antenna. This can be accomplished in many different ways leading to a plethora of antenna designs. The vast majority of designs are fed with a balanced line (unlike a monopole ante... | Gain when referring to an antenna refers to what about radiated power? | {
"answer_start": [
483
],
"text": [
"concentration"
]
} |
572f3f63947a6a140053c819 | Antenna_(radio) | Antennas more complex than the dipole or vertical designs are usually intended to increase the directivity and consequently the gain of the antenna. This can be accomplished in many different ways leading to a plethora of antenna designs. The vast majority of designs are fed with a balanced line (unlike a monopole ante... | Where is the power that is distributed originating from? | {
"answer_start": [
824
],
"text": [
"the transmitter"
]
} |
572f425b04bcaa1900d767e9 | Antenna_(radio) | For instance, a phased array consists of two or more simple antennas which are connected together through an electrical network. This often involves a number of parallel dipole antennas with a certain spacing. Depending on the relative phase introduced by the network, the same combination of dipole antennas can operate... | How many antenna would make up a phased array? | {
"answer_start": [
41
],
"text": [
"two or more"
]
} |
572f425b04bcaa1900d767ec | Antenna_(radio) | For instance, a phased array consists of two or more simple antennas which are connected together through an electrical network. This often involves a number of parallel dipole antennas with a certain spacing. Depending on the relative phase introduced by the network, the same combination of dipole antennas can operate... | What determines if the antenna creates a broadside array or an end fire array? | {
"answer_start": [
227
],
"text": [
"relative phase"
]
} |
572f425b04bcaa1900d767eb | Antenna_(radio) | For instance, a phased array consists of two or more simple antennas which are connected together through an electrical network. This often involves a number of parallel dipole antennas with a certain spacing. Depending on the relative phase introduced by the network, the same combination of dipole antennas can operate... | What are the two standard antenna types? | {
"answer_start": [
516
],
"text": [
"omnidirectional or weakly directional"
]
} |
572f425b04bcaa1900d767ea | Antenna_(radio) | For instance, a phased array consists of two or more simple antennas which are connected together through an electrical network. This often involves a number of parallel dipole antennas with a certain spacing. Depending on the relative phase introduced by the network, the same combination of dipole antennas can operate... | How are antennas oriented when arranged with specific spacing? | {
"answer_start": [
161
],
"text": [
"parallel"
]
} |
572f4583947a6a140053c84a | Antenna_(radio) | However a log-periodic dipole array consists of a number of dipole elements of different lengths in order to obtain a somewhat directional antenna having an extremely wide bandwidth: these are frequently used for television reception in fringe areas. The dipole antennas composing it are all considered "active elements"... | What type of antenna formation is made up of multiple dipole elements of varying lengths? | {
"answer_start": [
10
],
"text": [
"log-periodic dipole array"
]
} |
572f4583947a6a140053c84b | Antenna_(radio) | However a log-periodic dipole array consists of a number of dipole elements of different lengths in order to obtain a somewhat directional antenna having an extremely wide bandwidth: these are frequently used for television reception in fringe areas. The dipole antennas composing it are all considered "active elements"... | What is the benefit of this formation type? | {
"answer_start": [
157
],
"text": [
"extremely wide bandwidth"
]
} |
572f4583947a6a140053c84d | Antenna_(radio) | However a log-periodic dipole array consists of a number of dipole elements of different lengths in order to obtain a somewhat directional antenna having an extremely wide bandwidth: these are frequently used for television reception in fringe areas. The dipole antennas composing it are all considered "active elements"... | What is a variation of this antenna type? | {
"answer_start": [
465
],
"text": [
"Yagi-Uda Antenna"
]
} |
572f4583947a6a140053c84c | Antenna_(radio) | However a log-periodic dipole array consists of a number of dipole elements of different lengths in order to obtain a somewhat directional antenna having an extremely wide bandwidth: these are frequently used for television reception in fringe areas. The dipole antennas composing it are all considered "active elements"... | What is the main application of these set ups? | {
"answer_start": [
213
],
"text": [
"television reception"
]
} |
572f5908b2c2fd140056805b | Antenna_(radio) | At low frequencies (such as AM broadcast), arrays of vertical towers are used to achieve directionality and they will occupy large areas of land. For reception, a long Beverage antenna can have significant directivity. For non directional portable use, a short vertical antenna or small loop antenna works well, with th... | For radio broadcast that one would hear in their car what type of towers are used? | {
"answer_start": [
53
],
"text": [
"vertical"
]
} |
572f5908b2c2fd140056805d | Antenna_(radio) | At low frequencies (such as AM broadcast), arrays of vertical towers are used to achieve directionality and they will occupy large areas of land. For reception, a long Beverage antenna can have significant directivity. For non directional portable use, a short vertical antenna or small loop antenna works well, with th... | If one wished to take an antenna to different locations, which type would be best? | {
"answer_start": [
256
],
"text": [
"short vertical antenna"
]
} |
572f5908b2c2fd140056805c | Antenna_(radio) | At low frequencies (such as AM broadcast), arrays of vertical towers are used to achieve directionality and they will occupy large areas of land. For reception, a long Beverage antenna can have significant directivity. For non directional portable use, a short vertical antenna or small loop antenna works well, with th... | Why is this specific antenna type used? | {
"answer_start": [
81
],
"text": [
"achieve directionality"
]
} |
572f5908b2c2fd140056805e | Antenna_(radio) | At low frequencies (such as AM broadcast), arrays of vertical towers are used to achieve directionality and they will occupy large areas of land. For reception, a long Beverage antenna can have significant directivity. For non directional portable use, a short vertical antenna or small loop antenna works well, with th... | What is a problem one might encounter when using a portable antenna? | {
"answer_start": [
358
],
"text": [
"impedance matching"
]
} |
572f5a60b2c2fd140056806b | Antenna_(radio) | An antenna lead-in is the transmission line (or feed line) which connects the antenna to a transmitter or receiver. The antenna feed may refer to all components connecting the antenna to the transmitter or receiver, such as an impedance matching network in addition to the transmission line. In a so-called aperture ante... | What is mainly responsible for the connection of the antenna to its end destinations? | {
"answer_start": [
3
],
"text": [
"antenna lead-in"
]
} |
572f5a60b2c2fd140056806c | Antenna_(radio) | An antenna lead-in is the transmission line (or feed line) which connects the antenna to a transmitter or receiver. The antenna feed may refer to all components connecting the antenna to the transmitter or receiver, such as an impedance matching network in addition to the transmission line. In a so-called aperture ante... | What is the group of elements used to join the elements of an antenna? | {
"answer_start": [
120
],
"text": [
"antenna feed"
]
} |
572f5a60b2c2fd140056806d | Antenna_(radio) | An antenna lead-in is the transmission line (or feed line) which connects the antenna to a transmitter or receiver. The antenna feed may refer to all components connecting the antenna to the transmitter or receiver, such as an impedance matching network in addition to the transmission line. In a so-called aperture ante... | What are the type of antennas used with satellite television called? | {
"answer_start": [
307
],
"text": [
"aperture antenna"
]
} |
572f5a60b2c2fd140056806e | Antenna_(radio) | An antenna lead-in is the transmission line (or feed line) which connects the antenna to a transmitter or receiver. The antenna feed may refer to all components connecting the antenna to the transmitter or receiver, such as an impedance matching network in addition to the transmission line. In a so-called aperture ante... | What can be used in place of a standard transmission line? | {
"answer_start": [
577
],
"text": [
"microwave antenna"
]
} |
572fdec904bcaa1900d76e0d | Antenna_(radio) | Monopole antennas consist of a single radiating element such as a metal rod, often mounted over a conducting surface, a ground plane. One side of the feedline from the receiver or transmitter is connected to the rod, and the other side to the ground plane, which may be the Earth. The most common form is the quarter-wav... | Monopole antennas consist of what element? | {
"answer_start": [
66
],
"text": [
"metal rod"
]
} |
572fdec904bcaa1900d76e0f | Antenna_(radio) | Monopole antennas consist of a single radiating element such as a metal rod, often mounted over a conducting surface, a ground plane. One side of the feedline from the receiver or transmitter is connected to the rod, and the other side to the ground plane, which may be the Earth. The most common form is the quarter-wav... | What are small monopoles used as? | {
"answer_start": [
775
],
"text": [
"nondirectional antennas"
]
} |
572fdec904bcaa1900d76e0e | Antenna_(radio) | Monopole antennas consist of a single radiating element such as a metal rod, often mounted over a conducting surface, a ground plane. One side of the feedline from the receiver or transmitter is connected to the rod, and the other side to the ground plane, which may be the Earth. The most common form is the quarter-wav... | What the most common form? | {
"answer_start": [
309
],
"text": [
"quarter-wave monopole"
]
} |
572fdec904bcaa1900d76e10 | Antenna_(radio) | Monopole antennas consist of a single radiating element such as a metal rod, often mounted over a conducting surface, a ground plane. One side of the feedline from the receiver or transmitter is connected to the rod, and the other side to the ground plane, which may be the Earth. The most common form is the quarter-wav... | What has vertical polarization? | {
"answer_start": [
434
],
"text": [
"Monopoles"
]
} |
572fdefb947a6a140053cd8c | Antenna_(radio) | The most widely used class of antenna, a dipole antenna consists of two symmetrical radiators such as metal rods or wires, with one side of the balanced feedline from the transmitter or receiver attached to each. A horizontal dipole radiates in two lobes perpendicular to the antenna's axis. A half-wave dipole the most ... | What is the most widley used antenna class? | {
"answer_start": [
41
],
"text": [
"dipole antenna"
]
} |
572fdefb947a6a140053cd8d | Antenna_(radio) | The most widely used class of antenna, a dipole antenna consists of two symmetrical radiators such as metal rods or wires, with one side of the balanced feedline from the transmitter or receiver attached to each. A horizontal dipole radiates in two lobes perpendicular to the antenna's axis. A half-wave dipole the most ... | What radiates two lobes perpendicular to the antennas axis? | {
"answer_start": [
215
],
"text": [
"horizontal dipole"
]
} |
572fdefb947a6a140053cd8e | Antenna_(radio) | The most widely used class of antenna, a dipole antenna consists of two symmetrical radiators such as metal rods or wires, with one side of the balanced feedline from the transmitter or receiver attached to each. A horizontal dipole radiates in two lobes perpendicular to the antenna's axis. A half-wave dipole the most ... | Besides low gain antennas, what is also used as driven elements in complicated higher gain types of antennas? | {
"answer_start": [
455
],
"text": [
"dipoles"
]
} |
572fdefb947a6a140053cd8f | Antenna_(radio) | The most widely used class of antenna, a dipole antenna consists of two symmetrical radiators such as metal rods or wires, with one side of the balanced feedline from the transmitter or receiver attached to each. A horizontal dipole radiates in two lobes perpendicular to the antenna's axis. A half-wave dipole the most ... | How much gain does a half-wave dipole have? | {
"answer_start": [
405
],
"text": [
"2.15 dBi"
]
} |
572fe7e6a23a5019007fcb1b | Antenna_(radio) | A necessary condition for the aforementioned reciprocity property is that the materials in the antenna and transmission medium are linear and reciprocal. Reciprocal (or bilateral) means that the material has the same response to an electric current or magnetic field in one direction, as it has to the field or current i... | What must be true of the antenna and transmission medium for the repiprocity rule to apply ? | {
"answer_start": [
131
],
"text": [
"linear and reciprocal"
]
} |
572fe7e6a23a5019007fcb1d | Antenna_(radio) | A necessary condition for the aforementioned reciprocity property is that the materials in the antenna and transmission medium are linear and reciprocal. Reciprocal (or bilateral) means that the material has the same response to an electric current or magnetic field in one direction, as it has to the field or current i... | What is one material that does not have this quality? | {
"answer_start": [
529
],
"text": [
"ferrite"
]
} |
572fe7e6a23a5019007fcb1e | Antenna_(radio) | A necessary condition for the aforementioned reciprocity property is that the materials in the antenna and transmission medium are linear and reciprocal. Reciprocal (or bilateral) means that the material has the same response to an electric current or magnetic field in one direction, as it has to the field or current i... | How can the lack of this quality be used in an everyday way? | {
"answer_start": [
680
],
"text": [
"radar"
]
} |
572fe7e6a23a5019007fcb1c | Antenna_(radio) | A necessary condition for the aforementioned reciprocity property is that the materials in the antenna and transmission medium are linear and reciprocal. Reciprocal (or bilateral) means that the material has the same response to an electric current or magnetic field in one direction, as it has to the field or current i... | What is called when the direction of the elctrical current does not make a difference to the current? | {
"answer_start": [
154
],
"text": [
"Reciprocal"
]
} |
572fe81ab2c2fd14005685a9 | Antenna_(radio) | Antennas are characterized by a number of performance measures which a user would be concerned with in selecting or designing an antenna for a particular application. Chief among these relate to the directional characteristics (as depicted in the antenna's radiation pattern) and the resulting gain. Even in omnidirectio... | How could one deide what type of antenna is nedded for a project? | {
"answer_start": [
42
],
"text": [
"performance measures"
]
} |
572fe81ab2c2fd14005685aa | Antenna_(radio) | Antennas are characterized by a number of performance measures which a user would be concerned with in selecting or designing an antenna for a particular application. Chief among these relate to the directional characteristics (as depicted in the antenna's radiation pattern) and the resulting gain. Even in omnidirectio... | What would most likely be the main concern in making this decision? | {
"answer_start": [
199
],
"text": [
"directional characteristics"
]
} |
572fe81ab2c2fd14005685ab | Antenna_(radio) | Antennas are characterized by a number of performance measures which a user would be concerned with in selecting or designing an antenna for a particular application. Chief among these relate to the directional characteristics (as depicted in the antenna's radiation pattern) and the resulting gain. Even in omnidirectio... | How would you distribute power to allow for a greater gain? | {
"answer_start": [
432
],
"text": [
"horizontal directions"
]
} |
572fe81ab2c2fd14005685ac | Antenna_(radio) | Antennas are characterized by a number of performance measures which a user would be concerned with in selecting or designing an antenna for a particular application. Chief among these relate to the directional characteristics (as depicted in the antenna's radiation pattern) and the resulting gain. Even in omnidirectio... | What is often the most imprtant crediting factor of antennas? | {
"answer_start": [
591
],
"text": [
"efficiency"
]
} |
572fe85db2c2fd14005685b1 | Antenna_(radio) | Resonant antennas are expected to be used around a particular resonant frequency; an antenna must therefore be built or ordered to match the frequency range of the intended application. A particular antenna design will present a particular feedpoint impedance. While this may affect the choice of an antenna, an antenna'... | Which antenna type would be best for a project requiring a specific frequency? | {
"answer_start": [
0
],
"text": [
"Resonant antennas"
]
} |
572fe85db2c2fd14005685b2 | Antenna_(radio) | Resonant antennas are expected to be used around a particular resonant frequency; an antenna must therefore be built or ordered to match the frequency range of the intended application. A particular antenna design will present a particular feedpoint impedance. While this may affect the choice of an antenna, an antenna'... | How could an antenna be made to coordinate with the needed frequency? | {
"answer_start": [
111
],
"text": [
"built or ordered"
]
} |
572fe85db2c2fd14005685b3 | Antenna_(radio) | Resonant antennas are expected to be used around a particular resonant frequency; an antenna must therefore be built or ordered to match the frequency range of the intended application. A particular antenna design will present a particular feedpoint impedance. While this may affect the choice of an antenna, an antenna'... | What factor would result in a desired feedback independence? | {
"answer_start": [
188
],
"text": [
"particular antenna design"
]
} |
572fe85db2c2fd14005685b4 | Antenna_(radio) | Resonant antennas are expected to be used around a particular resonant frequency; an antenna must therefore be built or ordered to match the frequency range of the intended application. A particular antenna design will present a particular feedpoint impedance. While this may affect the choice of an antenna, an antenna'... | If you were unable to choose the antenna you wanted how could you still achieve this result? | {
"answer_start": [
403
],
"text": [
"matching network"
]
} |
572fe8da04bcaa1900d76e8b | Antenna_(radio) | An antenna transmits and receives radio waves with a particular polarization which can be reoriented by tilting the axis of the antenna in many (but not all) cases. The physical size of an antenna is often a practical issue, particularly at lower frequencies (longer wavelengths). Highly directional antennas need to be ... | What is the essential difference in radio waves transmitted by an antenna? | {
"answer_start": [
64
],
"text": [
"polarization"
]
} |
572fe8da04bcaa1900d76e8c | Antenna_(radio) | An antenna transmits and receives radio waves with a particular polarization which can be reoriented by tilting the axis of the antenna in many (but not all) cases. The physical size of an antenna is often a practical issue, particularly at lower frequencies (longer wavelengths). Highly directional antennas need to be ... | How can this be adjusted more easily than changing antenna types? | {
"answer_start": [
104
],
"text": [
"tilting the axis"
]
} |
572fe8da04bcaa1900d76e8d | Antenna_(radio) | An antenna transmits and receives radio waves with a particular polarization which can be reoriented by tilting the axis of the antenna in many (but not all) cases. The physical size of an antenna is often a practical issue, particularly at lower frequencies (longer wavelengths). Highly directional antennas need to be ... | When might the size of an antenna cause an issue? | {
"answer_start": [
238
],
"text": [
"at lower frequencies"
]
} |
572fe8da04bcaa1900d76e8f | Antenna_(radio) | An antenna transmits and receives radio waves with a particular polarization which can be reoriented by tilting the axis of the antenna in many (but not all) cases. The physical size of an antenna is often a practical issue, particularly at lower frequencies (longer wavelengths). Highly directional antennas need to be ... | What size antenna would not be good when the antenna needs to be directional? | {
"answer_start": [
609
],
"text": [
"small"
]
} |
572fe8da04bcaa1900d76e8e | Antenna_(radio) | An antenna transmits and receives radio waves with a particular polarization which can be reoriented by tilting the axis of the antenna in many (but not all) cases. The physical size of an antenna is often a practical issue, particularly at lower frequencies (longer wavelengths). Highly directional antennas need to be ... | There is a relationship between the size of the antenna and the size of the wavelength with what antenna type? | {
"answer_start": [
281
],
"text": [
"Highly directional"
]
} |
572fe936b2c2fd14005685c0 | Antenna_(radio) | The majority of antenna designs are based on the resonance principle. This relies on the behaviour of moving electrons, which reflect off surfaces where the dielectric constant changes, in a fashion similar to the way light reflects when optical properties change. In these designs, the reflective surface is created by ... | What particle's migration does the resonance principle rely on? | {
"answer_start": [
109
],
"text": [
"electrons"
]
} |
572fe936b2c2fd14005685bf | Antenna_(radio) | The majority of antenna designs are based on the resonance principle. This relies on the behaviour of moving electrons, which reflect off surfaces where the dielectric constant changes, in a fashion similar to the way light reflects when optical properties change. In these designs, the reflective surface is created by ... | What is the basis for the way most antennas are developed? | {
"answer_start": [
49
],
"text": [
"resonance principle"
]
} |
572fe936b2c2fd14005685c1 | Antenna_(radio) | The majority of antenna designs are based on the resonance principle. This relies on the behaviour of moving electrons, which reflect off surfaces where the dielectric constant changes, in a fashion similar to the way light reflects when optical properties change. In these designs, the reflective surface is created by ... | What type of surface is formed by the tip of a conductor? | {
"answer_start": [
287
],
"text": [
"reflective"
]
} |
572fe936b2c2fd14005685c2 | Antenna_(radio) | The majority of antenna designs are based on the resonance principle. This relies on the behaviour of moving electrons, which reflect off surfaces where the dielectric constant changes, in a fashion similar to the way light reflects when optical properties change. In these designs, the reflective surface is created by ... | How would you place the conductor in relation to the signal you wished to obtain? | {
"answer_start": [
590
],
"text": [
"perpendicular"
]
} |
572fe97ca23a5019007fcb23 | Antenna_(radio) | The radio signal's electrical component induces a voltage in the conductor. This causes an electrical current to begin flowing in the direction of the signal's instantaneous field. When the resulting current reaches the end of the conductor, it reflects, which is equivalent to a 180 degree change in phase. If the condu... | What part of the radio signal creates voltage? | {
"answer_start": [
19
],
"text": [
"electrical component"
]
} |
572fe97ca23a5019007fcb24 | Antenna_(radio) | The radio signal's electrical component induces a voltage in the conductor. This causes an electrical current to begin flowing in the direction of the signal's instantaneous field. When the resulting current reaches the end of the conductor, it reflects, which is equivalent to a 180 degree change in phase. If the condu... | What would the electric current always gravitate to? | {
"answer_start": [
160
],
"text": [
"instantaneous field"
]
} |
572fe97ca23a5019007fcb25 | Antenna_(radio) | The radio signal's electrical component induces a voltage in the conductor. This causes an electrical current to begin flowing in the direction of the signal's instantaneous field. When the resulting current reaches the end of the conductor, it reflects, which is equivalent to a 180 degree change in phase. If the condu... | What is the outcome when a curren is reflected> | {
"answer_start": [
280
],
"text": [
"180 degree change in phase"
]
} |
572fe97ca23a5019007fcb26 | Antenna_(radio) | The radio signal's electrical component induces a voltage in the conductor. This causes an electrical current to begin flowing in the direction of the signal's instantaneous field. When the resulting current reaches the end of the conductor, it reflects, which is equivalent to a 180 degree change in phase. If the condu... | What amount of phase change would return a signal to its originial state? | {
"answer_start": [
580
],
"text": [
"360 degree"
]
} |
572fe9e4b2c2fd14005685c7 | Antenna_(radio) | The ordinary half-wave dipole is probably the most widely used antenna design. This consists of two 1⁄4-wavelength elements arranged end-to-end, and lying along essentially the same axis (or collinear), each feeding one side of a two-conductor transmission wire. The physical arrangement of the two elements places them ... | What is the most popular antenna type? | {
"answer_start": [
13
],
"text": [
"half-wave dipole"
]
} |
572fe9e4b2c2fd14005685c9 | Antenna_(radio) | The ordinary half-wave dipole is probably the most widely used antenna design. This consists of two 1⁄4-wavelength elements arranged end-to-end, and lying along essentially the same axis (or collinear), each feeding one side of a two-conductor transmission wire. The physical arrangement of the two elements places them ... | What is the current usually beng put into it or pulled out of? | {
"answer_start": [
432
],
"text": [
"transmission line"
]
} |
572fe9e4b2c2fd14005685c8 | Antenna_(radio) | The ordinary half-wave dipole is probably the most widely used antenna design. This consists of two 1⁄4-wavelength elements arranged end-to-end, and lying along essentially the same axis (or collinear), each feeding one side of a two-conductor transmission wire. The physical arrangement of the two elements places them ... | Elements in a half wave dipole and on an identical axis are said to be what? | {
"answer_start": [
191
],
"text": [
"collinear"
]
} |
572fe9e4b2c2fd14005685ca | Antenna_(radio) | The ordinary half-wave dipole is probably the most widely used antenna design. This consists of two 1⁄4-wavelength elements arranged end-to-end, and lying along essentially the same axis (or collinear), each feeding one side of a two-conductor transmission wire. The physical arrangement of the two elements places them ... | What antenna type is a portion of the half wave dipole? | {
"answer_start": [
676
],
"text": [
"Monopoles"
]
} |
572fe9e4b2c2fd14005685cb | Antenna_(radio) | The ordinary half-wave dipole is probably the most widely used antenna design. This consists of two 1⁄4-wavelength elements arranged end-to-end, and lying along essentially the same axis (or collinear), each feeding one side of a two-conductor transmission wire. The physical arrangement of the two elements places them ... | What popular type combines more that one antenna? | {
"answer_start": [
847
],
"text": [
"folded dipole"
]
} |
572fea66b2c2fd14005685d1 | Antenna_(radio) | The standing wave forms with this desired pattern at the design frequency, f0, and antennas are normally designed to be this size. However, feeding that element with 3f0 (whose wavelength is 1⁄3 that of f0) will also lead to a standing wave pattern. Thus, an antenna element is also resonant when its length is 3⁄4 of a ... | What frequency are antennas normally designed to be? | {
"answer_start": [
75
],
"text": [
"f0"
]
} |
572fea66b2c2fd14005685d2 | Antenna_(radio) | The standing wave forms with this desired pattern at the design frequency, f0, and antennas are normally designed to be this size. However, feeding that element with 3f0 (whose wavelength is 1⁄3 that of f0) will also lead to a standing wave pattern. Thus, an antenna element is also resonant when its length is 3⁄4 of a ... | What can be added to f0 to create a standing wave pattern? | {
"answer_start": [
166
],
"text": [
"3f0"
]
} |
572fea66b2c2fd14005685d3 | Antenna_(radio) | The standing wave forms with this desired pattern at the design frequency, f0, and antennas are normally designed to be this size. However, feeding that element with 3f0 (whose wavelength is 1⁄3 that of f0) will also lead to a standing wave pattern. Thus, an antenna element is also resonant when its length is 3⁄4 of a ... | What multiple is essential for wavelengths? | {
"answer_start": [
370
],
"text": [
"1⁄4"
]
} |
572fea66b2c2fd14005685d4 | Antenna_(radio) | The standing wave forms with this desired pattern at the design frequency, f0, and antennas are normally designed to be this size. However, feeding that element with 3f0 (whose wavelength is 1⁄3 that of f0) will also lead to a standing wave pattern. Thus, an antenna element is also resonant when its length is 3⁄4 of a ... | How are waves which are used in the ways discussed controlled? | {
"answer_start": [
518
],
"text": [
"harmonically"
]
} |
572feda5b2c2fd14005685ed | Antenna_(radio) | The quarter-wave elements imitate a series-resonant electrical element due to the standing wave present along the conductor. At the resonant frequency, the standing wave has a current peak and voltage node (minimum) at the feed. In electrical terms, this means the element has minimum reactance, generating the maximum c... | How do quarter wave elements act in relation to a series relevant electrical element? | {
"answer_start": [
26
],
"text": [
"imitate"
]
} |
572feda5b2c2fd14005685ee | Antenna_(radio) | The quarter-wave elements imitate a series-resonant electrical element due to the standing wave present along the conductor. At the resonant frequency, the standing wave has a current peak and voltage node (minimum) at the feed. In electrical terms, this means the element has minimum reactance, generating the maximum c... | What frequency develops a current peak? | {
"answer_start": [
132
],
"text": [
"resonant frequency"
]
} |
572feda5b2c2fd14005685ef | Antenna_(radio) | The quarter-wave elements imitate a series-resonant electrical element due to the standing wave present along the conductor. At the resonant frequency, the standing wave has a current peak and voltage node (minimum) at the feed. In electrical terms, this means the element has minimum reactance, generating the maximum c... | How would you describe a current that has maximum efficiency? | {
"answer_start": [
277
],
"text": [
"minimum reactance"
]
} |
572feda5b2c2fd14005685f0 | Antenna_(radio) | The quarter-wave elements imitate a series-resonant electrical element due to the standing wave present along the conductor. At the resonant frequency, the standing wave has a current peak and voltage node (minimum) at the feed. In electrical terms, this means the element has minimum reactance, generating the maximum c... | What could be the best possible output versus input ratio? | {
"answer_start": [
504
],
"text": [
"lossless"
]
} |
572ff30304bcaa1900d76f11 | Antenna_(radio) | It is possible to use the impedance matching concepts to construct vertical antennas substantially shorter than the 1⁄4 wavelength at which the antenna is resonant. By adding an inductance in series with the antenna, a so-called loading coil, the capacitive reactance of this antenna can be cancelled leaving a pure resi... | For use with more than one channel changes are made to increase what property? | {
"answer_start": [
26
],
"text": [
"impedance matching"
]
} |
572ff30304bcaa1900d76f12 | Antenna_(radio) | It is possible to use the impedance matching concepts to construct vertical antennas substantially shorter than the 1⁄4 wavelength at which the antenna is resonant. By adding an inductance in series with the antenna, a so-called loading coil, the capacitive reactance of this antenna can be cancelled leaving a pure resi... | What could be coupled with an antenna to form pure resistance? | {
"answer_start": [
178
],
"text": [
"inductance"
]
} |
572ff30304bcaa1900d76f13 | Antenna_(radio) | It is possible to use the impedance matching concepts to construct vertical antennas substantially shorter than the 1⁄4 wavelength at which the antenna is resonant. By adding an inductance in series with the antenna, a so-called loading coil, the capacitive reactance of this antenna can be cancelled leaving a pure resi... | What element would this pure resistance be coupled with? | {
"answer_start": [
360
],
"text": [
"transmission line"
]
} |
572ff30304bcaa1900d76f14 | Antenna_(radio) | It is possible to use the impedance matching concepts to construct vertical antennas substantially shorter than the 1⁄4 wavelength at which the antenna is resonant. By adding an inductance in series with the antenna, a so-called loading coil, the capacitive reactance of this antenna can be cancelled leaving a pure resi... | What phrase describes the process of purposely using a lower standing antenna at a less than peak frequency? | {
"answer_start": [
617
],
"text": [
"electrical lengthening"
]
} |
572ff31bb2c2fd140056863b | Antenna_(radio) | The end result is that the resonant antenna will efficiently feed a signal into the transmission line only when the source signal's frequency is close to that of the design frequency of the antenna, or one of the resonant multiples. This makes resonant antenna designs inherently narrowband, and they are most commonly u... | If your were unable to match the source frequency with the design frequency of the antenna what could you use? | {
"answer_start": [
213
],
"text": [
"resonant multiples"
]
} |
572ff31bb2c2fd140056863c | Antenna_(radio) | The end result is that the resonant antenna will efficiently feed a signal into the transmission line only when the source signal's frequency is close to that of the design frequency of the antenna, or one of the resonant multiples. This makes resonant antenna designs inherently narrowband, and they are most commonly u... | What is the most common application of resonant antennas? | {
"answer_start": [
331
],
"text": [
"single target signal"
]
} |
572ff31bb2c2fd140056863d | Antenna_(radio) | The end result is that the resonant antenna will efficiently feed a signal into the transmission line only when the source signal's frequency is close to that of the design frequency of the antenna, or one of the resonant multiples. This makes resonant antenna designs inherently narrowband, and they are most commonly u... | What antenna setup type is generally used for TV viewing? | {
"answer_start": [
244
],
"text": [
"resonant"
]
} |
572ff31bb2c2fd140056863e | Antenna_(radio) | The end result is that the resonant antenna will efficiently feed a signal into the transmission line only when the source signal's frequency is close to that of the design frequency of the antenna, or one of the resonant multiples. This makes resonant antenna designs inherently narrowband, and they are most commonly u... | For use with more than one channel changes are made to increase what property? | {
"answer_start": [
702
],
"text": [
"bandwidth"
]
} |
572ff545a23a5019007fcbb3 | Antenna_(radio) | The amount of signal received from a distant transmission source is essentially geometric in nature due to the inverse square law, and this leads to the concept of effective area. This measures the performance of an antenna by comparing the amount of power it generates to the amount of power in the original signal, mea... | What accounts for the geometry involved in the use of an antenna? | {
"answer_start": [
111
],
"text": [
"inverse square law"
]
} |
572ff545a23a5019007fcbb5 | Antenna_(radio) | The amount of signal received from a distant transmission source is essentially geometric in nature due to the inverse square law, and this leads to the concept of effective area. This measures the performance of an antenna by comparing the amount of power it generates to the amount of power in the original signal, mea... | How is the compactness of the signal measured? | {
"answer_start": [
368
],
"text": [
"Watts per square metre"
]
} |
572ff545a23a5019007fcbb6 | Antenna_(radio) | The amount of signal received from a distant transmission source is essentially geometric in nature due to the inverse square law, and this leads to the concept of effective area. This measures the performance of an antenna by comparing the amount of power it generates to the amount of power in the original signal, mea... | What type of project would call for more than one element used together? | {
"answer_start": [
716
],
"text": [
"higher performance"
]
} |
572ff659b2c2fd1400568661 | Antenna_(radio) | Returning to the basic concept of current flows in a conductor, consider what happens if a half-wave dipole is not connected to a feed point, but instead shorted out. Electrically this forms a single 1⁄2-wavelength element. But the overall current pattern is the same; the current will be zero at the two ends, and reach... | What is a half wave dipole need to be coupled with in most instances? | {
"answer_start": [
130
],
"text": [
"feed point"
]
} |
572ff659b2c2fd1400568662 | Antenna_(radio) | Returning to the basic concept of current flows in a conductor, consider what happens if a half-wave dipole is not connected to a feed point, but instead shorted out. Electrically this forms a single 1⁄2-wavelength element. But the overall current pattern is the same; the current will be zero at the two ends, and reach... | What part of the current is usually strongest? | {
"answer_start": [
338
],
"text": [
"center"
]
} |
572ff659b2c2fd1400568663 | Antenna_(radio) | Returning to the basic concept of current flows in a conductor, consider what happens if a half-wave dipole is not connected to a feed point, but instead shorted out. Electrically this forms a single 1⁄2-wavelength element. But the overall current pattern is the same; the current will be zero at the two ends, and reach... | What does this result in? | {
"answer_start": [
411
],
"text": [
"standing wave pattern"
]
} |
572ff659b2c2fd1400568664 | Antenna_(radio) | Returning to the basic concept of current flows in a conductor, consider what happens if a half-wave dipole is not connected to a feed point, but instead shorted out. Electrically this forms a single 1⁄2-wavelength element. But the overall current pattern is the same; the current will be zero at the two ends, and reach... | Element used to provide support to the original signal are called? | {
"answer_start": [
883
],
"text": [
"passive elements"
]
} |
572ff739b2c2fd140056866f | Antenna_(radio) | A Yagi-Uda array uses passive elements to greatly increase gain. It is built along a support boom that is pointed toward the signal, and thus sees no induced signal and does not contribute to the antenna's operation. The end closer to the source is referred to as the front. Near the rear is a single active element, typ... | What can take advantage of these elements to add more gain? | {
"answer_start": [
2
],
"text": [
"Yagi-Uda array"
]
} |
572ff739b2c2fd1400568670 | Antenna_(radio) | A Yagi-Uda array uses passive elements to greatly increase gain. It is built along a support boom that is pointed toward the signal, and thus sees no induced signal and does not contribute to the antenna's operation. The end closer to the source is referred to as the front. Near the rear is a single active element, typ... | Does this device improve the operation of the antenna? | {
"answer_start": [
169
],
"text": [
"does not contribute"
]
} |
572ff739b2c2fd1400568671 | Antenna_(radio) | A Yagi-Uda array uses passive elements to greatly increase gain. It is built along a support boom that is pointed toward the signal, and thus sees no induced signal and does not contribute to the antenna's operation. The end closer to the source is referred to as the front. Near the rear is a single active element, typ... | What is the name for passive elements nearer to the source of the signal? | {
"answer_start": [
404
],
"text": [
"directors"
]
} |
572ff739b2c2fd1400568672 | Antenna_(radio) | A Yagi-Uda array uses passive elements to greatly increase gain. It is built along a support boom that is pointed toward the signal, and thus sees no induced signal and does not contribute to the antenna's operation. The end closer to the source is referred to as the front. Near the rear is a single active element, typ... | Adding more elements to a Yagi-Uda would have what effect? | {
"answer_start": [
524
],
"text": [
"increasingly directional"
]
} |
572ff872b2c2fd140056868b | Antenna_(radio) | It is also possible to use multiple active elements and combine them together with transmission lines to produce a similar system where the phases add up to reinforce the output. The antenna array and very similar reflective array antenna consist of multiple elements, often half-wave dipoles, spaced out on a plane and ... | What can be paired with transmission lines to create phases that would support output? | {
"answer_start": [
36
],
"text": [
"active elements"
]
} |
572ff872b2c2fd140056868c | Antenna_(radio) | It is also possible to use multiple active elements and combine them together with transmission lines to produce a similar system where the phases add up to reinforce the output. The antenna array and very similar reflective array antenna consist of multiple elements, often half-wave dipoles, spaced out on a plane and ... | What is the most common element used to create a single in phase signal? | {
"answer_start": [
275
],
"text": [
"half-wave dipoles"
]
} |
572ff872b2c2fd140056868d | Antenna_(radio) | It is also possible to use multiple active elements and combine them together with transmission lines to produce a similar system where the phases add up to reinforce the output. The antenna array and very similar reflective array antenna consist of multiple elements, often half-wave dipoles, spaced out on a plane and ... | What must be precise in order to create this signal at output? | {
"answer_start": [
373
],
"text": [
"phase lengths"
]
} |
572ff872b2c2fd140056868e | Antenna_(radio) | It is also possible to use multiple active elements and combine them together with transmission lines to produce a similar system where the phases add up to reinforce the output. The antenna array and very similar reflective array antenna consist of multiple elements, often half-wave dipoles, spaced out on a plane and ... | What is a more complicated occurrence of the single in-phase producing antenna? | {
"answer_start": [
442
],
"text": [
"log-periodic"
]
} |
572ff92704bcaa1900d76f8d | Antenna_(radio) | Reflection of the original signal also occurs when it hits an extended conductive surface, in a fashion similar to a mirror. This effect can also be used to increase signal through the use of a reflector, normally placed behind the active element and spaced so the reflected signal reaches the element in-phase. Generall... | If you wanted to somehow clone the original signal you could use? | {
"answer_start": [
62
],
"text": [
"extended conductive surface"
]
} |
572ff92704bcaa1900d76f8e | Antenna_(radio) | Reflection of the original signal also occurs when it hits an extended conductive surface, in a fashion similar to a mirror. This effect can also be used to increase signal through the use of a reflector, normally placed behind the active element and spaced so the reflected signal reaches the element in-phase. Generall... | What effect would the use of a reflector have on a signal? | {
"answer_start": [
157
],
"text": [
"increase"
]
} |
572ff92704bcaa1900d76f8f | Antenna_(radio) | Reflection of the original signal also occurs when it hits an extended conductive surface, in a fashion similar to a mirror. This effect can also be used to increase signal through the use of a reflector, normally placed behind the active element and spaced so the reflected signal reaches the element in-phase. Generall... | What allowance can be made for gaps without loss of performance? | {
"answer_start": [
396
],
"text": [
"less than 1⁄10"
]
} |
572ff92704bcaa1900d76f90 | Antenna_(radio) | Reflection of the original signal also occurs when it hits an extended conductive surface, in a fashion similar to a mirror. This effect can also be used to increase signal through the use of a reflector, normally placed behind the active element and spaced so the reflected signal reaches the element in-phase. Generall... | What is the most recognized type of an antenna that has its basis in reflection? | {
"answer_start": [
603
],
"text": [
"parabolic reflector"
]
} |
572ffb1ba23a5019007fcbf3 | Antenna_(radio) | Another extreme case of impedance matching occurs when using a small loop antenna (usually, but not always, for receiving) at a relatively low frequency where it appears almost as a pure inductor. Resonating such an inductor with a capacitor at the frequency of operation not only cancels the reactance but greatly magni... | What magnifies the small radiation resistance of a loop? | {
"answer_start": [
230
],
"text": [
"a capacitor at the frequency of operation"
]
} |
572ffb1ba23a5019007fcbf5 | Antenna_(radio) | Another extreme case of impedance matching occurs when using a small loop antenna (usually, but not always, for receiving) at a relatively low frequency where it appears almost as a pure inductor. Resonating such an inductor with a capacitor at the frequency of operation not only cancels the reactance but greatly magni... | What is resonated by a capacitor along with the receiver tuning that maintains resonance over the AM broadcast band? | {
"answer_start": [
453
],
"text": [
"small ferrite loop antenna"
]
} |
572ffb1ba23a5019007fcbf4 | Antenna_(radio) | Another extreme case of impedance matching occurs when using a small loop antenna (usually, but not always, for receiving) at a relatively low frequency where it appears almost as a pure inductor. Resonating such an inductor with a capacitor at the frequency of operation not only cancels the reactance but greatly magni... | What is used in most AM broadcaster receivers? | {
"answer_start": [
371
],
"text": [
"loop"
]
} |
572ffb1ba23a5019007fcbf6 | Antenna_(radio) | Another extreme case of impedance matching occurs when using a small loop antenna (usually, but not always, for receiving) at a relatively low frequency where it appears almost as a pure inductor. Resonating such an inductor with a capacitor at the frequency of operation not only cancels the reactance but greatly magni... | When using a small loop antenna at a low frequency, what may occur? | {
"answer_start": [
24
],
"text": [
"impedance matching"
]
} |
573001d0b2c2fd1400568722 | Antenna_(radio) | Antenna tuning generally refers to cancellation of any reactance seen at the antenna terminals, leaving only a resistive impedance which might or might not be exactly the desired impedance (that of the transmission line). Although an antenna may be designed to have a purely resistive feedpoint impedance (such as a dipo... | What is left after antenna tuning? | {
"answer_start": [
111
],
"text": [
"resistive impedance"
]
} |
573001d0b2c2fd1400568721 | Antenna_(radio) | Antenna tuning generally refers to cancellation of any reactance seen at the antenna terminals, leaving only a resistive impedance which might or might not be exactly the desired impedance (that of the transmission line). Although an antenna may be designed to have a purely resistive feedpoint impedance (such as a dipo... | Where does cancellation of any reactance seen? | {
"answer_start": [
77
],
"text": [
"antenna terminals"
]
} |
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