ANALOG TO ANALOG Conversion - Networking.pptx

This is the ppt presentation from the field of computer science and subject networking.

1. ANALOG TO ANALOG CONVERSION NETWWORING

2. MODULATION The process of changing the digital signals into Analog Signals is called Modulation. Change Analog information by analog signals is also known as Modulation.

3. WHY TO MODULATE ANALOG SIGNAL? Modulation is needed . . . • If the medium is Bandpass in nature. • BANDPASS - the range of frequencies which are transmitted through bandpass filter .

4. BANDPASS FILTER An electronic device or circuit. • Allows signals between two specific frequencies to pass. • Prevents signals at unwanted frequencies. • Example – Radio

5. ANALOG To ANALOG CONVERSION Analog signals are modified to represent analog data. • Also known as Analog Modulation. • Required when BANDPASS is used.

6. TYPES

7. AMPLITUDE MODULATION Process of changing the amplitude of high frequency carrier wave in accordance with intensity of signal is called AM. • Amplitude of the carrier wave : amplitude of the signal being modulated.

8. AMPLITUDE MODULATION

9. WHY WE NEED MULTIPLIER Has two analog inputs . • Output proportional to the product of the two amplitudes • Ex. MICROPHONES

10. AMPLITUDE MODULATION If the modulation signal frequency increases, the amplitude of the carrier changes at a greater rate. • B AM =2 B • BAND WIDTH of AM Signal = TWICE the BANDWIDTH of MODULATING Signal

11. ADVANTAGES • It is simple to implement. • It can be demodulated using a circuit consisting of very few components

12. Frequency Modulation 5. 12 The modulating signal changes the freq. f c of the carrier signal The bandwidth for FM is high It is approx. 10x the signal frequency

13. 5. 13 The total bandwidth required for FM can be determined from the bandwidth of the audio signal: B FM = 2(1 + β)B. Where  is usually 4. Note

14. 5. 14 Frequency Modulation

15. 5. 15 FM Band Allocation

16. Phase Modulation (PM) 5. 16 The modulating signal only changes the phase of the carrier signal. The phase change manifests itself as a frequency change but the instantaneous frequency change is proportional to the derivative of the amplitude. The bandwidth is higher than for AM.

17. 5. 17 Phase Modulation