how can information be transmitted using electromagentic radiation?

Answer 1

that's easy... you can produce a electromagnetic wave with an antenna, and the wave will have the exact same form as the electric current which will have produced it...
And when you receive the electromagnetic field with another antenna, the antenna retransforms it into the same electric current (only weaker).
You add a few components to boost the received signal and to "understand" the signal, and you got it! (understand the signal includes "listening for it" and decoding it with a prearanged "language")

now, if you want to know if you can do it, why don't you just turn your tv on or call someone on your cell phone : that's what you're doing...

that's the basics of all telecommunications...

Answer 2

You modulate a radio signal with the information you want to transmit. There's several different methods of doing this (Amplitude Modulation, Frequency Modulation, Phase Modulation, Frequency Shift Keying, etc)

Generally, you pick a frequency to serve as a 'carrier wave'. This is the frequency you tune your signal to.

The information you want to transmit is either already a signal (voice is a combination of several different frequencies, for example) or you will generate a signal using the data.

A digital binary signal using frequency shift keying would be the easiest example. If the data bit is a one, generate frequency A. If the data is a zero, generate frequency B.

The information signal (either freq A or freq B) and the carrier signal are 'multiplied' together and the composite signal is transmitted.

Once the receiver strips out the carrier signal, he will be left with frequency A if the data is a 1 and frequency B if the data is a zero.

If the carrier signal was 2.25 MHz, the 1's might be a 76 KHz signal and the 0's might be a 90KHz signal. You should also set a rate of transfer, other wise, how will you know whether you received 4 1's in a row or 5 1's in a row? If the data transfer rate was 2KHz, each bit should last 0.5 milliseconds. If the 76 KHz signal lasted 1.5 milliseconds, you would know you received 3 1's, not 2 or 1.

Answer 3

Radiowaves and microwaves are types of em radiation commonly used to transmit information. Lets take a simple analog example. You start with a general carrier/continous wave, CW. An info signal can then be used to modulate the CW. Two commonly used types of modulation are AM and FM. With AM the info signal is used to modulate the amplitude of the CW. The signal is then transmitted. A filtering or tuning circuit, at the receiver, then demodulates the signal.

Answer 4

In and of light, an electromagnetic wave is a light transmitter, so in effect a electromagnetic transducer or tranciever could be utilized to transmit data or infirmation.
With a little thought obne could use the EM Wave to carry a signal and or Physical data/matter.

Answer 5

Radio waves are electromagnetic radiation.
Light is also electromagnetic radiation.

So radio, TV, fiber optics, the printed word, ...

If you want to know the mechanism behind broadcasting information using radio waves, that's another question.

Answer 6

It is called a "Radio signal" and the concept has been around for quite a long time.
The first transmissions by Radio were in what was called AM, "Amplitude modulation", whereby the wavelength remained constant, but the amplitude (height) varied to carry the signal.
Now, we use FM, "Frequency modulation", whereby the amplitude (height) remains constant, but the frequency (distance between successive waves) varies.

Answer 7

simply put, the EM wave parameters,( frequency, amplitude, phase) can be adjusted to represent various inputs states. in the digital world it is common to vary the phase. Older methods are FM (frequency Modulation on your radio) and AM (Amplitude Moulation)
the wave will be manipulated (modulated) and then transmitted, the receiver will know the modulation technique and can then reverse the process (demodulate) to recover the infomation.

Answer 8

Duh? have you ever hear of a cell phone?