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.

gollark: I should concatenate all my code together for competition 8.
gollark: I've already written my round 7 entry of course.
gollark: And Macron.
gollark: Actually, if they only block irc.osmarks.net, fun quirks of how stuff is set up means that you can just access [LITERALLY ANY SUBDOMAIN APART FROM SOME WHICH DO NOT WORK].osmarks.net.
gollark: Kit-: we can workaround DNS blocking with some effort.

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.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.