Question

Costa’s receiver is used for ________

(a) coherent detection of AM-SC signal

(b) asynchronous detection of AM-SC signal

(c) amplification of signal

(d) frequency mixing of signal

The question was posed to me in an international level competition.

I need to ask this question from Costas Loop in section Double Sideband Suppressed Carrier Modulation of Analog Communications

Answer 1

Correct answer is (a) coherent detection of AM-SC signal

Explanation: A Costa’s loop is based on phase-locked loop (PLL). The circuit recovers carrier frequency from the suppressed-carrier modulated signals like DSBSC and SSBSC and phase modulated signals like FSK and BFSK. It is generally used for coherent detection of AM-SC signal in receivers.