Extended hemispherical lens

The extended hemispherical lens is a commonly used lens for millimeter-wave electromagnetic radiation. Such lenses are typically fabricated from dielectric materials such as Teflon or silicon. The geometry consists of a hemisphere of radius R on a cylinder of length L, with the same radius.

Scanning performance

When a feed element is placed a distance d off the central axis, then the main beam will be steered an angle γ off-axis. The relation between d and γ can be determined from geometrical optics:[1]

This relation is used when designing focal plane arrays to be used with the extended hemispherical lens.

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gollark: ```LOLCODEBTW declaration of the BUKKITI HAS A [object] ITZ A BUKKITBTW creating a variable in a slots[object] HAS A [var] ITZ [value]BTW creating a function inside the BUKKITHOW IZ [object] [function name] (YR [argument1] (AN YR [argument2] (AN YR [argument3] ...))) [function code]IF U SAY SO```

See also

References
  1. Frid, Henrik (2016). "Closed-Form Relation Between the Scan Angle and Feed Position for Extended Hemispherical Lenses Based on Ray Tracing". IEEE Antennas and Wireless Propagation Letters.
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