Explanation: This describes **Plate modulation**. In plate modulation, the audio modulating signal is applied to the plate (anode) circuit of the RF power amplifier. For 100% amplitude modulation, the plate voltage must vary from zero to twice its DC quiescent value. This requires the audio amplifier to supply an audio power equal to 50% of the DC input power to the RF amplifier. The audio amplifier effectively "sees" the dynamic DC plate impedance of the RF amplifier as its load. Maintaining constant grid excitation voltage ensures the RF amplifier's output is primarily controlled by its plate voltage, leading to clean amplitude modulation with low distortion when properly designed. Grid or cathode modulation schemes require significantly less audio power for 100% modulation (typically a small percentage of DC input power) and present different load impedances to the modulator. Anode is another term for plate, but "Plate" is the standard terminology for this method.