UC Irvine

A new up/down converter system for LTE-A transmitter was presented. The chosen architecture eliminates the problem of LO-RF feedthrough in heterodyne transmitters. Using passive mixers and high bandwidth circuitry, acceptable gain flatness and linearity is achieved, making this system suitable for polar modulation. The circuit incorporating a number of elements in the system was fabricated in a 0.18um BCD process that provides both high-voltage MOSFETS as well as low-voltage, high-speed MOSFETS, allowing implementation of both the PA and converter onto a single chip.