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AM superheterodyne radio receiver diagram

Short answer

The AM superheterodyne receiver converts the incoming RF signal to a fixed 455 kHz IF using a mixer and local oscillator. It consists of RF amplifier, mixer, local oscillator, IF amplifier, detector, AGC, audio amplifier, and speaker.

Draw a block diagram of AM super heterodyne radio receiver.

In a superheterodyne receiver, the incoming RF signal is converted to a fixed intermediate frequency (IF, 455 kHz for AM) before amplification and detection.

 Ant -> [RF amp] --> [Mixer] --> [IF amp] --+
                        ^                   |
                        |                   v
               [Local oscillator]      [Detector] --> AGC (to RF and IF amps)
               (fLO = fRF + 455 kHz)        |
                                            v
                                        [AF amp]
                                            |
                                            v
                                        [Speaker]
  • RF amplifier: selects and amplifies the wanted station and rejects the image frequency.
  • Mixer + local oscillator: produce fIF = fLO − fRF (a constant 455 kHz).
  • IF amplifier: gives most of the gain and selectivity.
  • Detector: recovers the audio from the AM envelope; it also gives the AGC voltage that controls the gain of the RF and IF stages.
  • Audio amplifier and speaker: amplify the audio and reproduce the sound.

✓ Answer checked by Claude Opus 5.5 (high effort)

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