Design of a highly linear WiFi6/6E Front-End RFIC in SiGe BiCMOS technology

The IEEE 802.11ax standard, commonly referred as Wi-Fi6, enhances bandwidth efficiency in dense, high-traffic environments compared to its predecessors. The introduction of Wi-Fi6e, operating within the nearly 6 GHz band, creates additional channels and reduces interference, making it an ideal choice for next-generation wireless communication systems. This advantages has driven a growing demand for advanced Front-End Modules (FEM) capable of supporting high data rates and efficient modulation schemes. This thesis explores the design and layout of Single Pole Double Throw (SPDT) switch and Low Noise Amplifier (LNA) for a FEM that operates across the entire 5–7 GHz Wi-Fi6e band, aiming to be competitive with other commercial solutions. The design is implemented using 130nm SiGe BiCMOS technology, which provides higher gain for both Transmission (TX) and Receiver (RX) stages, along with a lower Noise Figure (NF) in the RX stage compared to traditional CMOS technologies. Building on previous research, this work includes hands-on laboratory measurements of earlier design, identifying challenges and improvements to enhance overall system performance. An analysis of Triple Well (TW) MOSFET behavior was performed to address discrepancies observed in the SPDT during the measurement phase. This analysis led to a redesign aimed at improving the switch’s linearity, to enable the FEM to unlock the full potential of the power amplifier during transmission. The LNA redesign introduces dual-mode operation, offering a high-gain mode for small signal amplification and a high-linearity bypass mode for handling high-power signals without distortion. The gain stage employs HBTs, while the bypass path makes use of MOSFET for greater power efficiency. The chapters of this thesis cover the theoretical background and implementation challenges of Wi-Fi6e technology (Chapter.1), the TW-MOSFET analysis (Chapter.2), the design principles and improvements of the SPDT switch (Chapter.3) and LNA (Chapter.4), and the simulation results of the proposed FEM (Chapter.5).