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====== Antennas for receiving signals reflected from meteors ======

===== Plastic 1/4 lambda GroundPlane =====

It represents the basic antenna, currently used on most of our stations. It has an advantage of having small size and it is thus not difficult to install it on balcony, terrace, etc. Equally important is its relatively primitive designs which allows for easy construction suitable for beginners.
 
===== Other types of antennas =====

An interesting antenna design, that should solve the drawbacks of GP antennas is so-called [[http://on6wg.pagesperso-orange.fr/Doc/Antenne%20Eggbeater-Engl-Part1-Full.pdf|eggbeater]] or an antenna of [[http://en.wikipedia.org/wiki/Turnstile_antenna|Turn style]] type.

A pair of crossed dipoles above a conducting plane could also result in interesting experimental solutions as it would be probably possible to integrate the amplifier directly into the antenna. The resulting active antenna would have better noise parameters and reliability compared to design with separated GP antenna and LNA.

[[http://en.wikipedia.org/wiki/Discone_antenna|Discone antena]] has also be tested for receiving the reflected signal. Although it works, it has an disadvantage of high bandwidth, that causes a penetrations of undesirable signals.

===== Installation of antenna's preamplifier  =====

==== Preamplifier LNA01A ====

Good quality preamplifier is essential due to antenna's low gain and low intensities of reflected signal.

[[http://www.mlab.cz/Modules/CommRF/LNA01A/LNA01A_Bottom_Small.JPG|LNA01A]] represents a preamplifier designed for meteor detection in 2m band. It amplifies the signal from antenna and thus decrease the effect of receiver's own noise. It further reduces complications connected with signal transmission via coaxial cable (it compensates for the cable attenuation and so it is possible to use cheaper coaxial cable of RG58 type).

==== Further improvements ====

Antenna should fulfil these requirements.

* It should have larger gain than currently used Ground Plane.
  * Radiation pattern should not reach zero at zenith.
  * It should have hemispheric radiation pattern.
  * It should be possible to integrate it with an amplifier.
  * Radiation pattern and directionality should be made adjustable via phasing of more antennas.

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