How to realize the amplitude modulation of two signals has been produced. How to implement it on hardware? What is the principle?

When the amplitude of one signal differs greatly from that of the other signal, the two signals pass through a nonlinear element, which can be a diode or a diode. For example, one signal is sent to the base of the triode circuit and the other is sent to the transmitter, and the modulated signal can be obtained at the collector.