ECE :: Communication Systems
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It is required to increase the maximum range of a radar by a factor of two. The peak power transmitted in the radar system has to be increased by a factor of
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Armstrong F.M. transmitter performs frequency multiplication in stages
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A source generates three symbols with probabilities 0.25, 0.25, 0.50 at a rate of 3000 symbols per second. Assuming independent generation of symbols, the most efficient source encoder would have average bit rate is as
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The filter circuit for feeding tweeter has
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The use of SSB
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If a signal voltage Vs is accompanied by a noise voltage Vn the signal to noise ratio is
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Video signals are transmitted through
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A TV receiver has 20 kV EHT supply and total beam current (for 3 electron guns) of 1500 μA. The power handled by IHVT is
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Some possible disadvantages of high level modulation in TV transmitters are
- Video monitor has to supply high video voltages upto several hundred volts into highly capacitive loads drawing high current at video frequencies
- The grid modulated stage presents a varying load to its driver
- The linearity and high video driving power present design problems