network,signal . system, tv signal, video signal

1. NETWORK SYSTEM AND SIGNAL
Submitted By:- Submitted To:-
Pro. Hemant Meena
Khinya Ram(2013uee1597)

2. CONTENT
TV SIGNAL PROPAGATION
COMPOSITE VIDEO SIGNAL
VIDEO SIGNAL FOR COLOUR

3. TV SIGNAL PROPAGATION
Radio waves are electromagnetic waves, which when radiated from transmitting
antennas, travel through space to distant places, where they are picked up by
receiving antennas
Although space is the medium through which electromagnetic waves are
propagated, but depending on their wavelengths, there are three distinctive
methods by which propagation takes place.

4. TV SIGNAL PROPAGATION

5. COMPOSITE VIDEO SIGNAL
 A composite video signal consists of:
 Camera signal - corresponding to the desired picture information
 Blanking pulses – to make the retrace invisible
 Synchronizing pulses – to synchronize the transmitter and receiver scanning
 horizontal sync pulse
 vertical sync pulse
 their amplitudes are kept same
 but their duration are different
 needed consecutively and not simultaneously with the picture signal – so sent on a time division basis

6. COMPOSITE VIDEO SIGNAL

7. VIDEO SIGNAL FOR COLOUR
Desaturated colours
• Any colour is said to be desaturated when mixed with white
• In a colour camera output signal, Red colour is desaturated to a small amount, then the
Vg and Vb have lower values
• But as desaturation of red increases, Vg and Vb values are increased
• For 100% desaturation Vr = Vg =Vb

8. VIDEO SIGNAL FOR COLOUR
Colour video Frequencies:
• When the scene is not dominated by one or few colours the information to be transmitted occupies more
frequency spectrum
• It is discovered that colour frequencies need 1.5 Mhz band in order to transmit finest details of a scene
• The luminance signal frequency range is up to 5 Mhz

9. VIDEO SIGNAL FOR COLOUR
• Colour
voltage
amplitudes: