POLAR MODULATION USING PRODUCT MODE

Radio frequency (RF) transmitters and methods of their operation are disclosed. An exemplary RF transmitter includes an RF power amplifier (RFPA), a dynamic power supply (DPS), and a baseband processing unit. The baseband processing unit generates an amplitude modulation (AM) signal that the DPS follows to generate a DPS voltage VDD(t). The DPS voltage VDD(t) serves as a power supply for an output stage of the RFPA. Under most operating conditions the output stage is configured to operate in a compressed mode (C-mode), but is reconfigured to operate in a product mode (or "P-mode) during times low-magnitude events in the AM signal are conveyed to the DPS and become present in the DPS voltage VDD(t) produced by the DPS. Operating the output stage in P-mode overcomes the inability of C-mode operation to reproduce low-magnitude events contained in the AM signal at the RF output of the RFPA.