1.

In long distance communication, the similar potential wave produced from a carrier wave is V = V_(0) sin Omegat. On the other side, potential wave corresponding to data signal is , v = v_(0) sin omega t, "" v_(0) lt lt Omega. Superimposing data signal on carrier wave, generally two types of modulated waves are produced, they are: (a) Amplitude Modulated (AM) wave: V_("AM") = V_(0) (1 + beta_(1) sin omega t ) sin Omega t where, beta_(1) = k_(1)(v_(0))/(V_(0)) = modulation index ""(k_(1) " " constant). Frequency Modulated (FM) wave: V_("FM") = V_(0) sin(Omegat - beta_(2) cos omega t ) where, beta_(2) = k_(2)(v_(0))/(omega) = modulation index "" (k_(2) = constant). Mathematical analysis of two modulated waves shows that, for AM wave, apart from Omega frequency, there are two sine wave components of frequencies Omega - omega and Omega + omega. As a result, the bandwidth of the waves becomes (Omega + omega)-(Omega-omega) = 2omega. On the other hand, in FM wave, the number of sine wave components are infinite and their frequencies areOmegan pm, Omega pm 2omega,... . Basides that, if the dissipated power for a transmitting antenna to transmit a carrier wave be P_(c ) and dissipated power for transmitting AM and FM wave be P_(AM)and P_(FM) then, P_(AM) = P_(c )(1 + (beta^(2))/(2)), P_(FM) = P_(c ) In converting a carrier wave into an Amplitude Modulated (AM), modulation index was 0.05. Then, what would be the percentage increases in dissipated power at transmitting antenna?

Answer»

2.5
1.25
0.25
0.125

Solution :N/A


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