Reflector antennas are devices that reflects electromagnetic waves. They focus a beam signal into one point (called focal point) or directs a radiating signal into a beam. They are used when high gain (more than 30dBi is common) is required, typically for earth to space communication or microwave point-to-point links.
For theory see:
Orphanids, S: Electromagnetic Waves and Antennas, 2004-10, chapter 14: http://www.ece.rutgers.edu/~orfanidi/ewa/ch20.pdf
Kraus, J.D., Marhefka, R.J.: Antennas for all applications, Mc Graw Hill 2003, chapter: Slot, Patch and Horn antennas (9)
Simulations - Cassegrain reflector:
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Cassegrain reflector antenna, surface current distribution. |
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Cassegrain reflector antenna, electric field (absolute value) at the cut. |
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Cassegrain reflector antenna, electric field animation at the cut. |
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3D radiation pattern of the Cassegrain antenna. |
Simulations - Offset reflector:
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Offset reflector antenna, distribution of the electric field at the surface. |
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Offset reflector antenna, distribution of the surface electric current. |
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Offset reflector antenna, radiation pattern. |
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Offset reflector antenna, animation of the electric current. |
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Offset reflector antenna, animation of the electric field. Note the main physical effect of the reflector: transformation of the spherical waves emanating from the horn to "plane" waves. |
Gallery:
