Millimeter Wave Power Amplifiers for Wireless Communication in Advanced Semiconductor Technologies

The exponential growth in wireless communication systems has brought the need for high-speed and high-frequency integrated circuits that operate in the millimeter-wave (mm-wave) frequency band. Power amplifiers (PAs) are a key component in these systems, and their design requires a careful balance between gain, efficiency, and linearity. To achieve these requirements, new technologies and techniques must be employed in the design of mm-wave PAs. In this thesis, we focus on the design and characterization of power amplifiers for 5G wireless communication systems. Silicon PAs are an attractive option for 5G systems due to their low cost as a result of the economies of scale, and compatibility with standard CMOS processes. However, designing a high-performance silicon PA for 5G systems is a challenging task due to the stringent requirements on linearity, efficiency, and bandwidth. On the other side, III-V compound semiconductors offer substantially better mm-wave performance but at a higher cost and lack compatibility with the standard CMOS processes. Both of these semiconductor technologies will be explored and compared with each other in different scenarios throughout the Chapters of this thesis. The thesis is divided into five main parts. In the first part, a comprehensive overview of the modeling of active and passive structures in both CMOS and III-V technologies is presented. The basics of embedding structures are also discussed in detail and a coupled line broadband model for transformers is presented. This part provides a solid foundation for the subsequent design and implementation of PAs in advanced semiconductor technologies. In the second part, the fundamental concepts of power amplifier design are reviewed. The importance of linearity in mm-wave PAs is emphasized, and an elaborate mathematical model is presented that simulates the effect of non-linear behavior (amplitude and phase non-linearity) on the constellation diagrams and the error vector magnitude of modulated signals. In the third part, the trade-offs in terms of performance and cost for different front-end technologies in phased array systems are provided. Different technologies are compared with each other based on a simple mathematical model. A design example is giving of a broadband and very compact transformer-coupled PA implemented in GaAs technology. Using a coupled line structure at the output that operates above the self-resonance frequency a very broadband matching network is a