FM (Frequency Modulation) is a method of encoding audio signals onto a radio wave by varying its frequency (rather than amplitude, as in AM). It delivers higher sound quality and is widely used for music broadcasting.

🔹 How FM Radio Works

1. Audio Input → Microphone converts sound into an electrical signal.
2. Modulation → The carrier wave’s frequency changes based on the audio signal.
3. Transmission → The modulated signal is broadcast via an antenna.
4. Reception → FM radio receivers (e.g., car stereos, smartphones) pick up and decode the signal.

Key Features of FM:

✅ Better sound quality (less noise, supports stereo audio).
✅ Resistant to interference (compared to AM).
❌ Shorter range (usually 50–100 km, affected by obstacles).

🔹 FM vs. AM Radio

🔹 FM Frequency Bands

• Standard FM Broadcast: 87.5–108 MHz (most countries).
• Japan FM Band: 76–90 MHz (slightly different range).
• FM Radio in Cars/TV Audio: 87.5–108 MHz (same as broadcast FM).

🔹 How to Listen to FM Radio

1. Traditional FM Radios (portable, home stereos).
2. Car Radios (built-in FM tuners).
3. Smartphones (some have FM chips—check if your device supports it).
4. Online Streaming (TuneIn, iHeartRadio, station websites).

🔹 Stereo FM & Subcarriers

• Stereo FM: Uses multiplexing to separate left/right audio channels.
• Subcarriers: Extra data like:
  • RDS (Radio Data System) → Displays song info, traffic alerts.
  • HD Radio (Digital FM) → Higher quality, extra channels.

🔹 Why FM is Still Popular

• Crystal-clear music (ideal for stations playing songs).
• Local coverage (good for city-based broadcasting).
• Emergency broadcasts (many countries use FM for alerts).