Which component creates the carrier wave in a transmitter?

• A. Demodulator
• B. Modulator
• C. Amplifier
• D. Oscillator

Answer: (D)

The carrier wave is the stable RF tone that carries the information, and the component that creates it is the oscillator. It generates a steady sinusoidal signal at the chosen carrier frequency, providing the unmodulated baseline that the modulator uses to encode the data. Without this stable carrier, modulation can’t imprint the information onto a radio frequency. The modulator takes the carrier from the oscillator and alters its amplitude, frequency, or phase according to the input signal to produce the modulated waveform. The amplifier simply boosts the modulated signal for transmission, but it doesn’t determine the carrier frequency. The demodulator in the receiver extracts the information from the received carrier, not generating it.