Question

The LNA of a transducer has failed during the transmission of a signal. Which component’s failure has caused this?

(a) Duplexer

(b) RF amplifier

(c) Antenna

(d) Mixer

This question was posed to me in examination.

Origin of the question is Communication Receivers topic in division Radio Transmitters, Communication Receivers, Multiplexing and Demultiplexing of Avionics

Answer 1

Correct option is (a) Duplexer

To elaborate: A duplexer is a device which acts as a switch and stops the high power transmission signals from entering into the receiver, which is tuned to handle very low power for better sensitivity. When the duplexer fails, the high power signals enter the receiver where the Low noise amplifier is damaged.