Radio Receiver – Block Diagram, Limitations | New Topic [2024]

In this note, we are going to learn about Radio Receiver, Its Block Diagram and Limitations as well. Welcome to Poly Notes Hub, a leading destination for engineering notes for diploma and degree engineering students.

Author Name: Arun Paul.

About AM Radio Receiver

Figure depicts the block diagram of a am or straight radio receiver. The aerial receives radio waves from several broadcasting stations. The desired radio wave is picked by the R.F. amplifier, which uses a tuned parallel circuit. The tuned RF amplifiers amplify the particular radio wave. The amplified radio wave is sent into the detection circuit. This circuit derives an audio signal from a radio wave. The detector’s output is an audio signal that is amplified through one or more stages. The amplified audio signal is routed to the speaker for sound reproduction.

AM Radio Receiver Block Diagram

Below shows the block diagram of radio receiver –

1. Receiving Aerial or Antenna: Captures radio frequency (RF) signals from the atmosphere. These signals are electromagnetic waves sent out by various broadcasting stations.
2. RF Amplifier: It is amplifies the antenna’s weak RF impulses. This enhances signal strength without considerably increasing noise, allowing future steps to process the signal more easily.
3. Detector: Removes audio information (modulating signal) from the modulated IF signal. The modulation type determines the type of detector utilized. AM detectors may use diodes, whereas FM detectors may use discriminators or phase-locked loops.
4. AF Amplifier: Amplifies the audio signal retrieved by the detector to a level sufficient to drive the speaker. It guarantees that the audio signal is sufficiently strong to be heard clearly.
5. Speaker: Converts the amplified audio signal into listenable sound waves. The speaker’s diaphragm moves in reaction to the audio stream, resulting in sound.

Limitations of Radio Receiver

Here are some limitations of this type of receivers –

1. AM radio receivers employ tuned circuits. Because the value of variable capacitors must be changed to tune to the desired station, the Q of the variable capacitors varies significantly between closed and open positions. This affects the sensitivity and selectivity of radio receivers.
2. There is too much interference of adjacent stations.