BCICTS Primer Course

Design methodologies for handheld PAs

Abstract:
In this course, we will delve into the fascinating world of RF power amplifiers (PAs). These essential components play a crucial role in radio transmitters and communication systems. Whether you’re a seasoned engineer or just starting out, this session promises valuable insights into the heart of wireless communication.

We’ll begin by reviewing the foundational characteristics of modulated signals. Understanding these properties is essential for designing efficient PAs. Signal fidelity, linearity, and distortion will be explored in the context of PA design. We will then dwell into classic PA Theory. Using an idealized transistor model, we’ll develop intuition about critical PA concepts, such as loadline tuning (how to optimize the loadline for maximum power delivery), harmonic termination, strategies to improve efficiency, and the definition of the canonical Amplifier Classes (A, B, AB, C). We’ll discuss the pros and cons of each amplifier class and their real-world applications.

Then we will approach Practical PA design.

We will discuss Class F and J matching topologies, exploring matching networks and efficiency considerations related to second harmonic termination. Then a sample GaAs HBT PA Design will be developed. We will apply theoretical concepts to design a 2-stage PA using a simplified GaAs HBT model. Finally an overview of advanced efficiency enhancement techniques will be given: Doherty and Envelope Tracking.

Join us for an engaging exploration of RF power amplifiers, where theory meets practical design. By the end of this primer, you’ll be well-equipped to tackle real-world challenges in RF PA design and optimization.

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Calogero D. Presti received the Ph.D. degree in electronics and automation engineering from the University of Catania, Italy, in 2008, working on CMOS Power Amplifiers and Silicon Photonics. During 2009 he was a postdoctoral researcher at UC San Diego, mainly working on PA digital predistortion and envelope tracking. In 2010 he joined Qualcomm Inc., San Diego, CA, where he was part of the team that started the RF Front-End business in the company. There he designed several CMOS and GaAs PAs, and led some front-end module integration for sub-6GHz cellular applications. In 2019 he joined IDT (now part of Renesas) where he designed all the PAs used in mm-Wave beamformers (cellular, satcom, and radar) and occasionally supported the sub-6GHz businesses. Recently, he joined Kyocera, where he designs mm-wave power amplifiers for 5G infrastructure. Since 2017 he teaches the Power Amplifier design class at UC San Diego.