A. Rectifier and high pass filter
B. Rectifier and low pass filter
C. Amplifier and low pass filter
D. Amplifier and high pass filter
Answer - B. Rectifier and low pass filter
Explanation - The envelope detector is a very simple method of demodulation. It consists of a rectifier (anything that will pass current in one direction only), and a low - pass filter. The rectifier may be in the form of a single diode, or may be more complex.