In order for a signal to be transmitted wirelessly, it is necessary for the signal to be conveyed into free space, then recovered from free space and restored to its original form. This is accomplished by 2 devices: transmitters and receivers. The transmitter generates the carrier frequency, puts the information on it and delivers it to free space through an antenna. There are three main parts to a transmitter. An oscillator generates the RF carrier frequency that will be sent over the air. This carrier is modulated by the data that is to be sent. An amplifier takes the modulated carrier and increases its power. The more power added to the carrier, the longer the range of the system. Finally the RF signal contained in the wires inside the transmitter is radiated into free space by the antenna.