and 3.5 kHz. It is applied as one input to an ideal bal- anced modulator, and the other input is a sinusoid having a frequency of 1.2 MHz. (a) List the frequencies appear- ing at the output of the balanced modulator. (b) Determine the required transmission bandwidth.
The modulating signal has a component at the following frequencies: 0.5 kHz, 1.5 kHz and 3.5 kHz.
The carrier frequency is: 1.2 MHz=1200 kHz
Let us consider the modulating signal is given by:
;
And the carrier frequency:
The balanced modulator is used for generating the Double sideband suppressed carrier(DSB-SC) modulated signal. So that the output of the Balance modulator :
![f(t) = [E, cos(Wmit) + E, cos(Wm2t) + Ez cos(mat)] cos(wit)](https://media.cheggcdn.com/coop/c15/c15d613c-4b2e-471e-98f4-3949f5be3207/1586670337233_blob.png)
![f(t) = 5; [2 cos(Wmat) cos(wÄ…t)] + 52 [2 cos(Wm2t) cos(wÄ…t)] + *> [2 cos(Wm3 t) cos(wet)]](https://media.cheggcdn.com/coop/777/77703371-4709-4af0-8b5c-6c801dd9dac8/1586670337237_blob.png)
![f (t) = [cos(wc + Wma)t + cos(wc – Wma)t} + { [cos(we + Wm2)t + cos(wc – Wm2)t] We + Wm3)t + cos(we - Wm3)t) ......... (1)](https://media.cheggcdn.com/coop/cfb/cfb6f992-b49c-451e-b218-8435e913721c/1586670337289_blob.png)
Given data:
Or the frequency in rad/sec
Put the all frequency values in the equation (1)
![f(t) = (21(1.2 x 106 +0.5 x 103)t + cos(21t(1.2 x 106 – 0.5 x 103)t] + [cos(21(1.2 x 106 + 1.5 x 103)t + cos(21(1.2 x 106 – 1](https://media.cheggcdn.com/coop/05c/05cf4cdb-1449-40e9-b624-2f359e0c4b56/1586670337206_blob.png)
(a) List the frequency appears at the output of the balanced modulator
The frequency component available in the modulated signal:
The upper sideband frequency component of the first modulated signal:
The Lower sideband frequency component of the first modulated signal:
The upper sideband frequency component of the second modulated signal:
The Lower sideband frequency component of the second modulated signal:
The upper sideband frequency component of the third modulated signal:
The lower sideband frequency component of the third modulated signal:
The frequency spectrum is:
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