A fully digital architecture for wideband wireless transmitters

A fully digital architecture for wideband wireless transmitters is presented, which replaces high dynamic- range analog circuits with high-speed digital circuits and thus offers lower cost and higher performance compared to those of conventional analog transmitters. The proposed transmitter modulates wideband data in Cartesian coordinates and generates its RF output using a fully Digital Quadrature Modulator (DQM). The novel architecture employs a single digital-to-RF converter, as it is based on fully digital combining of the quadrature baseband signals. The design is based on a standard 90 nm CMOS process and is suitable for integration with a digital signal processor, memory and logic implemented in such digital process. Although the presented results demonstrate compliance of the transmitter´s output with the IEEE 802.16a (WiMAX) standard, the proposed architecture may also be used for many other wideband wireless and non-wireless communication standards.