Post on 12-Apr-2017
transcript
Frequency modulation
By:ch. Gopi Chand
In Frequency modulation there are two types
1. Narrow Band FM 2. Wide Band FMFirst lets know about the
frequency modulation
The First Frequency Modulation was invented by Edwin Howard Armstrong in
December-18-1890
How Frequency modulation Generates
Frequency Modulation
Block Diagram of FM
Frequency Modulation
Modulation Index
IF Modulation Index (β) = 1
IF Modulation Index (β) = 25
Spectrum of Frequency Modulation
Practical Examples of Frequency modulation
Advantages of Frequency Modulation
Resilient to noise Resilient to signal strength
variations Does not require linear
amplifiers in the transmitter Enables greater efficiency than
many other modes
Disadvantages of Frequency Modulation
Requires more complicated demodulator
Some other modes have higher data spectral efficiency
Sidebands extend to infinity either side
Narrow Band FM
Modulation index is less than 1 Maximum Modulating Frequency
is usually 3KHZ and Maximum frequency deviation is 75KHZ
Block Diagram of Narrow Band FM
Spectrum of Narrow Band FM
References
B.P.Lathi, Modren Digital And Analog Communication System
en.wikipedia.org http://www.radioelectronics.com
Any Queries?
Thank You