Comparison between single band and concurrent multi-band linear power amplifiers

Currently the multiple wireless data transmission technologies have been commercially implemented, such as long-term evolution (LTE), Wi-Fi, and Bluetooth. There is a keen requirement to combine the power amplifiers for those technologies into a single one which can amplifies concurrent multi-band signals. On the physically layer, there are two popular architectures, namely parallel single-band power amplifiers and concurrent multi-band power amplifiers. In this thesis, quantitative comparison between parallel single-band power amplifiers and concurrent multi-band power amplifiers has been presented theoretically in the aspects of area, drain efficiency and linearity. Methods of calculating drain efficiency is derived for concurrent multi-band PAs for different frequency ratios. Linearity issues of concurrent multiband power amplifiers have been addressed based on the concepts of gain compression and intermodulation distortion. Final, area consumption has been compared for both architectures with current technologies. Results of the drain efficiency map versus 2-D frequency ratio are plotted in figures for class A, B and C. Linearity degradation of concurrent multi-band has been derived mathematically.