It would seem to me that an antenna made of hot anything would be inherently noisy. Noise is usually the limiting factor in receiveing weak signals, so great care is taken to preserve signal captured by the antenna without introcducing noise. This is why Low Noise Amplifiers (LNAs) are used at the front end of a receiver system, very near the antenna. THe idea is to introduce as little noise as possible while the signal appearing at the antenna is amplified to a level that the subsequent electronics can process it and extract information.
Thermal noise is found in all (practical) systems, and is the primary parameter that limits the distance a signal of a set amplitude can travel and stil be received. It sets the "noise floor". Thermal noise, also known as Johnson Noise, is proportional to temperature. Check out... http://en.wikipedia.org/wiki/Thermal_noise
If the antenna is a high temeprature ionized gas, isn't it goign to be noisy? That would seem to limit its practical uses.
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It would seem to me that an antenna made of hot anything would be inherently noisy. Noise is usually the limiting factor in receiveing weak signals, so great care is taken to preserve signal captured by the antenna without introcducing noise. This is why Low Noise Amplifiers (LNAs) are used at the front end of a receiver system, very near the antenna. THe idea is to introduce as little noise as possible while the signal appearing at the antenna is amplified to a level that the subsequent electronics can process it and extract information. Thermal noise is found in all (practical) systems, and is the primary parameter that limits the distance a signal of a set amplitude can travel and stil be received. It sets the "noise floor". Thermal noise, also known as Johnson Noise, is proportional to temperature. Check out... http://en.wikipedia.org/wiki/Thermal_noise If the antenna is a high temeprature ionized gas, isn't it goign to be noisy? That would seem to limit its practical uses.