Consider the statements about a radar beacon (RACON / transponder): It is also called a transponder. It includes a pulse transmitter, a receiver, and an antenna. It replies with its own fixed (preset) transmitter power once it detects an interrogation, even when the received signal is weak. Which statements are correct?

Introduction / Context:
Radar beacons (RACONs) and transponders are cooperative targets that detect interrogations and transmit replies at their own power level. They are used in maritime navigation aids, IFF (Identification Friend or Foe), and secondary surveillance radar systems to enhance detection and provide identification or bearing information.

Given Data / Assumptions:

• The device is cooperative and responds to an external interrogation.
• It contains RF front-end receive circuitry, a timing/logic section, and a transmitter with antenna.
• Reply power is generated by the beacon’s transmitter, not by amplifying the incoming pulse.

Concept / Approach:

A transponder architecture includes a receiver to detect incoming pulses, a processing block to validate and time the response, and a transmitter to send a coded reply via an antenna. As long as the interrogation exceeds the detection threshold, the reply is transmitted at a preset power, largely independent of the received signal strength. This distinguishes cooperative beacons from passive reflectors.

Step-by-Step Solution:

Verification / Alternative check:

Specifications for marine RACONs and aviation transponders list fixed output powers (e.g., watts or kilowatts peak) and minimum trigger levels, confirming independence of reply power from input amplitude once detected.

Why Other Options Are Wrong:

• Omitting any of 1–3 leaves out an essential property of transponders or misstates their power behavior.

Common Pitfalls:

Confusing active transponders with passive retro-reflectors; assuming reply power scales with received power like a linear amplifier.

Final Answer:

All