Describe briefly the three factors which justify

(a) Describe briefly the three factors which justify the need for translating a low frequency signal into high frequencies before transmission.
(b) Figure shows a block diagram of a detector for AM signal.

Draw the waveforms for the (i) input AM wave at A, (ii) output B at the rectifier, and (iii) output signal at C.

(a) There are three factors :
(i) Wider Band width : High frequency provide
wider bandwidth.
(ii) Distance : High frequency wave used to carry baseband signals (low frequency signal) over a distance of several thousand kilometres.
(iii) Cost : High frequency transmits with low
cost.