# SDR and amplitude modulated signals

Can I view every signal that has been transmitted using software defined radio as a amplitude modulated signal? For example I could make a frequency modulated baseband signal in GNU Radio and connect it to Adalm Pluto sink. Since analog part of Pluto SDR involves frequency mixing does it mean on top of FM I get AM?

A bit of trigonometry shows that this is equivalent to an amplitude and phase modulated signal; in other words, a quadrature signal is equivalent to $$A(t)\cos(2\pi f_c t + \phi(t))$$.