A CMOS 2V quadrature direct up-converter chip for DCS-1800 integration

This paper presents a 2V, full CMOS transmitter circuit to be included in a DCS-1800 wireless system. The paper discusses the design plan of the transmitter including the optimized interface with the differential oscillator, the poly-phase filter, the mixers and the preamplifying output driver. Traditional inter-building block buffers have been questioned, resulting in a transistor level optimization of the total transmit path as one building block. The measurements show that the DCS-1800 linearity and noise specifications are met. The 0.25µm, 2-metal layer chip has been realized in a standard CMOS technology.