Communicating With Waves - Terminology

People can communicate with each other using electromagnetic (typically radio) waves, sound waves or ultrasound but these systems have features in common. These include

  • A transducer which changes a signal from one form to another eg sound to electrical energy.

  • An encoder which translates the signal into a form which can be easily transmitted. This might be changing an electrical signal into an digital form easily transmitted as 0's and 1'

  • a modulator produces periodic variations in amplitude and/or frequency of the wave that carries the signal

  • An amplifier increases the amplitude of the signal

  • A transmitter sends the signal from one place to another

  • A receiver detects the transmitted signal

  • A demodulator seaparates a coded signal from the wave that carries it

  • A decoder translates the information from the form in which it is transmitted to one in which it can be understood