In a RADAR system, what is the expected output when no echoes are returned?

In a RADAR system, when no echoes are returned, the expected output is that no signal is developed. This is because the fundamental principle of RADAR involves sending out a signal (an electromagnetic wave) and waiting for that signal to bounce off a target and return as an echo. If there are no echoes returned, it indicates that either there are no objects within the RADAR's range to reflect the signal or the transmitted signal has not encountered anything that could cause a reflection.

When this happens, the detection circuitry of the RADAR system does not receive any reflected signals to process, and as a result, there is no output generated for the receiver. The system may remain in a standby mode or continue transmitting, but without any echoes being returned, there will be no meaningful output signal developed from the received data. This concept aligns with basic RADAR operation principles, where the presence of an echo signifies an object, and its absence signifies the lack of detectable objects.