Fm receiver

FM receiver its components and instillation.

1. PROJECT NAME. FM RECEIVER

2. Group Members. NASRULLAH KHAN (Group Leader) 13EL 07 YOUSAF KHAN 13EL 59 QADEEM KHAN 13EL 72

3. Radio Receiver. In radio communications a receiver is an electronic circuit that receives radio waves and converts the information carried by them to a useable form. It rejects the unwanted signal. It demodulate the carrier signal to get back the original modulating signal.

4. classification of radio receivers R adio receivers are classified in to the fallowing types 1. A.M . broadcast receivers 2. F.M. broadcast receivers

5. AM Receiver. AM Receivers is an electronic circuit which receive Amplitude Modulated signals. AM Radio receiver range from 535 KHz to 1705 KHz AM Receiver and transmitter are simple but it need synchronization AM Transmitters were first carried out successfully in the mid of 1870s.

6. FM Receiver. FM receiver is the circuit that receive Frequency Modulated signals. Its frequency rages from 88 to 108 Mega Hertz. FM Receiver and transmitters are more complex as compare to AM Receiver. FM Receiver was developed in United State in 1930s.

7. circuit diagram of FM RECEIVER

8. Components of FM Receiver.

9. Trimmer capacitor Trimmer capacitor is a variable capacitor which is used to initially set the oscillator frequency value in a circuit.

10. Transistor BF 494 It is a medium frequency transistor which is used in FM, AM receiver for low noise mixer.

11. IC LM 386 IC LM 386 is an integrated circuit used in FM receivers as a low voltage audio power amplifier.

12. Telescopic Aerial It is an Antenna used in FM, AM and wireless phones to receive the signals. It convert the receiving signal in tiny Alternating Currents which are applied to receiver and the receiver extract the desired information.

13. Block Diagram.

14. Sections of Block D iagram of FM Receiver

15. RF amplifier. A radio frequency power amplifier (RF power amplifier) is a type of electronic amplifier  that converts a low-power  radio-frequency signal  into a higher power signal . Typically, RF power amplifiers drive the antenna of a  transmitter.

16. Mixer. In  electronics frequency mixer is a nonlinear electrical circuit that creates new frequencies from two signals applied to it. If two signals at frequencies  f 1  and  f 2  are applied to a mixer, and it produces new signals at the sum  f 1  +  f 2  and difference  f 1  −  f 2  of the original frequencies . Mixers are widely used to shift signals from one frequency range to another, a process known as  heterodyning.

17. Filter. Ceramic filters are electronic components used as the band pass element for Intermediate Frequency (IF) amplifier stages of an FM radio . It reject the unwanted signal received by antenna.

18. IF Amplifier. Intermediate Frequency Amplifier is used to amplify the Intermediate F requency received from filter. IF amplifier is used to strengthen the intermediate frequency (IF) before forwarded to the limiter block.

19. Limiter. The signal received from IF Amplifier is applied to limiter which remove noise from received signal and gives a constant amplitude signal. Limiter (delimiter): fatherly damping function which is modulated amplitude waves (the signal sent by the transmitter) in order to form a pure FM signal.

20. Demodulator. A demodulator is an electronic circuit that is used to recover the information content from the modulated carrier wave . Demodulation is extracting the original information-bearing signal from a modulated carrier wave. FM demodulation or detection involves changing the frequency variations in a signal into amplitude variations at baseband, e.g. audio .

21. AF Amplifier. In radio  equipment  Automatic Frequency Control (AFC), also called Automatic Fine Tuning (AFT), is a method or circuit to automatically keep a resonant circuit tuned to the frequency of an incoming radio signal. It is primarily used in  radio receivers to keep the receiver tuned to the frequency of the desired station.

22. Oscillator. In  electronics a local oscillator (LO) is an electronic oscillator used with a mixer to change the frequency of a signal. This frequency conversion process also called  heterodyning produces the sum and difference frequencies from the frequency of the local oscillator and frequency of the input signal . Processing a signal at a fixed frequency gives a radio receiver improved performance.

23. Model.

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