An RF transmitter includes a Cartesian to polar conversion section, a PLL, a DAC module, a mixing module, and a PA module. The Cartesian to polar conversion section converts a Cartesian based symbol stream into a polar based symbol stream. The PLL generates an oscillation when the RF transmitter is in a Cartesian mode or a phase modulated oscillation based on phase modulation information of the polar based symbol stream when the RF transmitter is in a polar mode. The mixing module mixes an analog Cartesian based signal with a local oscillation to produce a Cartesian based up converted signal when the RF transmitter is in the Cartesian mode and mixes an analog amplitude signal with a phase modulated local oscillation to produce a polar based up converted signal when the RF transmitter is in the polar mode. The PA module amplifies the Cartesian based up converted signal to produce an outbound RF signal when the RF transmitter is in the Cartesian mode and amplifies the polar based up converted signal to produce the outbound RF signal when the RF transmitter is in the polar mode.