Which option lists the two main types of modulation used in radio transmission?

Which option lists the two main types of modulation used in radio transmission?

• A. AM and FM
• B. PM and QM
• C. PWM and FM
• D. AM and PM

Answer: (A)

The two main modulation methods used in radio transmission are amplitude modulation and frequency modulation. Amplitude modulation works by varying the carrier wave’s strength in step with the incoming audio signal. This makes the signal easy to implement and capable of long-range transmission, but it also means noise that affects amplitude can degrade the received audio. Frequency modulation changes the carrier’s frequency in proportion to the input signal. This provides much better resistance to amplitude noise and generally higher fidelity for music, though it requires wider bandwidth and slightly more complex receivers. Other modulation types exist, but AM and FM are the primary schemes used for traditional radio broadcasting.

The two main modulation methods used in radio transmission are amplitude modulation and frequency modulation.

Amplitude modulation works by varying the carrier wave’s strength in step with the incoming audio signal. This makes the signal easy to implement and capable of long-range transmission, but it also means noise that affects amplitude can degrade the received audio.

Frequency modulation changes the carrier’s frequency in proportion to the input signal. This provides much better resistance to amplitude noise and generally higher fidelity for music, though it requires wider bandwidth and slightly more complex receivers.

Other modulation types exist, but AM and FM are the primary schemes used for traditional radio broadcasting.