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user:kurser:ham_vt2023_l7 [2026/03/22 18:18] – Updated antenna material to KonCEPT v2.6.1 lokauser:kurser:ham_vt2023_l7 [2026/03/22 18:34] (current) – Updated Swedish glossary. loka
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 ==Direction== ==Direction==
  
-The most ideal antenna is a single charge floating in free space, radiating as a sphere equally strongly in all directions. Such a single charge is known academically as an //isotropic radiator//. Practically, antennas are real objects and thus not single charges, meaning that the "radiation sphere" (made-up word) is very much not a sphere. Most antennas only //illuminate// (actual term) a smaller part of that hypothetical sphere, meaning that most of the EM field is sent/received from/to the antenna at that specific direction in space. The illuminated area is known as the //beam area// (SE: ??).+The most ideal antenna is a single charge floating in free space, radiating as a sphere equally strongly in all directions. Such a single charge is known academically as an //isotropic radiator//. Practically, antennas are real objects and thus not single charges, meaning that the "radiation sphere" (made-up word) is very much not a sphere. Most antennas only //illuminate// (actual term) a smaller part of that hypothetical sphere, meaning that most of the EM field is sent/received from/to the antenna at that specific direction in space. The illuminated area is known as the //beam area// (SE: strålrymdvinkel).
  
 How small that illuminated segment of the sphere is as opposed to size the entire sphere, is known as the //antenna directivity//. The directivity is often given in dB with respect to that ideal //isotropic radiator//. The unit is thus **dBi**. A very large part of an antenna's design specification, is its directivity. Different types of antennas have very different directivities. How small that illuminated segment of the sphere is as opposed to size the entire sphere, is known as the //antenna directivity//. The directivity is often given in dB with respect to that ideal //isotropic radiator//. The unit is thus **dBi**. A very large part of an antenna's design specification, is its directivity. Different types of antennas have very different directivities.
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 ^ English ^Svenska ^ Comment ^ ^ English ^Svenska ^ Comment ^
 +| -3 dB point     | Halvvärdesbredd       | | 
 +| Antenna array     | Gruppantenn       | | 
 +| Boom     | Bom       | | 
 +| Design factor     | Förkortningsfaktor       | | 
 +| Directors     | Direktorer, passiva element       | | 
 +| Driven element     | Matat element, aktivt element       | | 
 +| Elements     | Antennelement, spröt       | | 
 +| Gain     | Antennvinst       | | 
 +| Lobe     | Strålkägla       | | 
 +| Lobe beamwidth     | Öppningsvinkel       | | 
 +| Lobe pattern     | Strålningsdiagram       | | 
 +| Parasitic element     | Parasitelement       | | 
 +| Radio broadcast     | Rundradio       | | 
 +| Radome     | Radom       | | 
 +| Reflector     | Reflektorer       | | 
 | Resistor     | Motstånd       | |  | Resistor     | Motstånd       | | 
 +
  
user/kurser/ham_vt2023_l7.txt · Last modified: 2026/03/22 18:34 by loka