An RF module (radio frequency module) usually is a small electronic device widely used in electronic design to transmit or receive radio signals between two devices owing to the difficulty of designing radio circuitry. In an embedded system it is often desirable to communicate with another device wirelessly. This wireless communication can be accomplished through optical communication or through radio frequency communication. The corresponding frequency range varies between 30 kHz & 300 GHz. In this RF system, the digital data is represented as variations in the amplitude of carrier wave. This kind of modulation is known as amplitude shift keying.
Transmission through RF has several advantages. Firstly, signals through RF can travel through larger distances making it suitable for long range applications. Also, RF signals can travel even when there is an obstruction between transmitter and receiver. Next, RF transmission is more reliable and much stronger, because it utilizes a specific frequency.
This RF module comprises of an RF transmitter and an RF receiver. The transmitter or receiver pair operates at a frequency of 434 MHz. Besides, it is often used along with a pair of encoder/decoder. The encoder is used for encoding parallel data for transmission feed while reception is decoded by a decoder.