Which modulation technique is commonly used in TV broadcasting?

In television broadcasting, amplitude modulation (AM) is widely recognized as a traditional method for transmitting video signals, particularly for analog television. This technique works by varying the amplitude of the carrier wave in accordance with the brightness of the video signal.

When using AM, the signal itself is directly related to the brightness of the image, which means that darker areas of the image correspond to lower amplitude levels while brighter areas correspond to higher amplitudes. This modulation allows the receiver to reconstruct the picture based on the varying amplitudes of the transmitted signal.

While FM is utilized for audio signals in radio and certain eras of TV broadcasting (like FM for sound transmission), and other techniques like phase modulation and quadrature amplitude modulation (QAM) are more prevalent in digital services, AM is grounded in the history of television transmission as a standard method for video modulation.

This historical context and operational mechanism firmly establish amplitude modulation as a common technique in television broadcasting, especially in earlier systems.