How do radio antennas convert electrical energy into photon energy?

AI Thread Summary
Radio antennas convert electrical energy into photon energy by moving charged particles back and forth, which generates electromagnetic waves. A radio transmitter applies a changing voltage to the antenna, causing these electrical charges to oscillate and produce waves that carry energy. While a complete circuit is necessary for continuous current flow, it is not required to apply voltage or generate current momentarily. The discussion references the LC oscillator as a simple example of this principle. Understanding these mechanisms is crucial for grasping how radio transmission works.
MichaelsTech
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How do transmitters convert electrical signals into photon energy?
 
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Moving charged particles back and forth produces electromagnetic waves, just as you can produce waves in water by moving an object back and forth in the water.

A radio transmitter works by applying a changing voltage to the antenna, causing electrical charges in the antenna to move back and forth. These in turn create electromagnetic waves which travel outwards, carrying energy with them.
 
How can a voltage be applied if it is not a complete circuit?
 
MichaelsTech said:
How can a voltage be applied if it is not a complete circuit?

You need a complete circuit to get current to flow when your circuit is in equilibrium but you don't need a complete circuit to apply a voltage or to get current to flow for a very short time.

Google for "LC oscillator" for a simple example.
 
Thread 'Motional EMF in Faraday disc, co-rotating magnet axial mean flux'

Thread 'Motional EMF in Faraday disc, co-rotating magnet axial mean flux'

So here is the motional EMF formula. Now I understand the standard Faraday paradox that an axis symmetric field source (like a speaker motor ring magnet) has a magnetic field that is frame invariant under rotation around axis of symmetry. The field is static whether you rotate the magnet or not. So far so good. What puzzles me is this , there is a term average magnetic flux or "azimuthal mean" , this term describes the average magnetic field through the area swept by the rotating Faraday...
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