Ask Dr. SETI ®
I am attempting to warp my head around the concept of Antenna Temperature, and would like to ask if it could be simply summarized. I am curious to know is a higher or lower K better in terms of relating to the antenna performance in general for best results in the system. I understand all the variables such as radiation pattern, gain, object reflections, angles and such but simply is the result of the K value better to be higher or lower?
The Doctor Responds:
Short answer: the lower the K, the better.
Thank you for the quick reply and explanation. After all these years as a Microwave RF Engineer I never actually had much of concern for "Temperature" as all designs were short point to point terrestrial links. I am considering moving the microwave experience into the realms of satellite communications / DSN reception and researching small radio-telescopes. I always knew cooling of pre-amps was used in some practices and understood the reason behind this as electrical based heat but with the antenna side of theory was more of a weak spot for me beyond the typical to intermediate design theory.
and the Doctor Replies:
Physically cooling the antenna would have little advantage, because the major part of antenna temperature comes from the 290 Kelvin temperature of the Earth itself, picked up by the antenna backlobes and sidelobes.
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this page last updated 14 September 2019
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