Linearity and Efficiency in 5G mm-Wave Transmitters

Higher capacity and improved energy efficiency are driving forces in development of future and emerging wireless systems. mm-Wave frequencies and highly integrated active antenna array technologies are key technologies to enable this development. However, the transmitters for such applications face completely new challenges compared to the ones used in today’s single-antenna systems. We will show that linearity and efficiency are still key transmitter metrics that have to be addressed both at circuit and antenna array levels. We will exemplify circuit level efficiency and linearity through advanced 30GHz CMOS and SiGe PAs and transmitter designs. This will be followed by an array level analysis of linearity where advanced characterization and modeling of integrated mm-wave circuits and antenna simulations are combined to predict distortion and radiation characteristics in 5G transmitter applications. This is finally used as basis for improved low-complex digital pre-distortion linearization and over-the-air characterization methods.