Question

Consider the block diagram as shown in the figure below :


The input signal x(t) is an AM wave of bandwidth 10 kHz and carrier frequency that may lie anywhere in the range of 0.535 MHz to 1.605 MHz. It is required to translate this signal to a frequency band centered at a fixed intermediate frequency (IF) of 0.455 MHz. The range of tuning that must be provided in the local oscillator to achieve this requirement is

• A. 0.08 MHz < $f_L<1.15$ MHz
• B. 0.8 MHz < $f_L<1.51$ MHz
• C. 0.1 MHz < $f_L<0.115$ MHz
• D. 1.1 MHz < $f_L<1.5$ MHz

Answer 1

The correct option is A 0.08 MHz < $f_L<1.15$ MHz

(0.535 - 0.455) <$f_L<(1.605-0.455)$
0.08 MHz < $f_L<1.15$ MHz