This document discusses modern direct-conversion transmitter architectures. It describes using an LO running at twice the carrier frequency to minimize injection pulling. Another approach discussed is deriving frequencies through mixing the outputs of two oscillators, but this results in equal power being wasted at the unwanted carrier frequency. The document then introduces single-sideband mixing as an alternative, which suppresses the unwanted sideband. It analyzes the output spectrum of an SSB mixer in the presence of nonlinearity and mismatches. Finally, it presents a direct-conversion transmitter design using SSB mixing for carrier generation.