- #1
chef99
- 75
- 4
Homework Statement
A cell phone sends and receives electromagnetic waves in the microwave frequency range.
Explain the physics of how an oscillator creates these waves.
Homework Equations
n/a
The Attempt at a Solution
An electromagnetic wave is created by the functioning of the oscillator. A simple oscillator generally consists of an inductor, which stores energy as a magnetic field and a capacitator, which stores energy as an electric static field. Connect a charged capacitator to a circuit and it will discharge through the inductor. This will cause the inductor to create a magnetic field. The inductor will try and maintain the current, and in doing so charges the other plate of the capacitator. By the time the inductor’s magnetic field has collapsed, the capacitator has been charged but with the opposite polarity. The capacitator will again discharge through the inductor, again creating a magnetic field, but this time the current is moving in the opposite direction through the circuit. Repeating this process creates an oscillating current, which gets transmitted into the antenna of the transmitter. The accelerating oscillating charges have a changing electric field, which creates a changing a varying magnetic field, which creates a varying electric field. This pattern continues on in this order. This interaction between the electric and magnetic fields, perpendicular to each other, is what creates an electromagnetic wave that travels through space.
I understand this is a bit long so thanks for taking the time to read it. The reason it is so long is because the question says to explain the "physics" of it so I think I have to be pretty technical. I think I have explained it properly but if anyone sees otherwise I would value the feedback.