Here is a circuit of a remote control unit which makes use of the radio frequency signals to control various electrical appliances. This remote control unit has 4 channels which can be easily extended to 12. This circuit differs from similar circuits in view of its simplicity and a totally different concept of generating the control signals. Usually remote control circuits make use of infrared light to transmit control signals. Their use is thus limited to a very confined area and line-of-sight.source

This is a general purpose remote control project with using programmable PIC microcontrollers. Schematics are shown for using infrared (IR) or radio (RF) media. If you are not familiar with microcontroller programming, you can use fixed encoder and decoder integrated circuits instead. Well-known such IC-s are Holtek HT-12D, HT-12E and Motorola MC145026, MC145027, MC145028.source

The transmitter used the Colpitts circuit for generate high frequency.The oscillation frequency changes by the length of the wiring, the capacitance of the transistor and other condition. So, the way of making actually and ascertaining is realistic.FET amplification circuit is used for a high frequency amplification circuit of the receiver.It is because the getting of parts is easy. So, it doesn’t have high sensitivity.To make the receiver with high sensitivity, the circuit which used IC for FM receiver is good.source

These new ones should make it considerably easier to recognize the parts used for the project. The Ming RF transmitter and receiver boards used for this project are relatively inexpensive and perform admirably considering the meager price. Using the quarter wave antennas, I have had some excellent results with operating distance as well as overall operation. The Ming modules come ready to plug into your application and only require these simple interface circuits shown here to build your own complete RF remote control system.source