Provided in embodiments of the present application are a signal modulation circuit, method and related product. The circuit comprises: a first modulation unit, which is for receiving a first original carrier signal and a first modulation signal, and performing first modulation on the first original carrier signal according to the first modulation signal, so as to obtain a first carrier signal and/or a second carrier signal; and a second modulation unit, which is used for performing second modulation on the first carrier signal or the second carrier signal according to the first modulation signal, so as to obtain a first modulated signal, or performing third modulation on the first carrier signal or the second carrier signal according to the first modulation signal, so as to obtain a second modulated signal. By using the embodiments of the present application, the direct modulation of a millimeter wave can be achieved, and the architecture of a transmitter can be greatly simplified, power consumption of the transmitter is reduced, and chip implementation is facilitated.