Characterization of various types of power amplifiers

Abstract

Over the years, the wireless communication market has experienced remarkable development since the first handheld phone introduced by Motorola. Nowadays, the smartphone is one of the most indispensable personal items, with a wide variety of applications that can benefit our daily life. Consequently, the thirst to achieve better wireless transceiving system design, with a low market cost, has gradually become the primary goal of modern RFIC manufacturers.

In all RF transceivers, the power amplifier plays a key role in driving the antenna on the transmitting end, while low-noise amplifier boosts the receiving end signal. Together these components account for the basic operation of a duplexed system. Among the various requirements in designing a power amplifier, PAE (power added efficiency) and linearity are the two most important characteristics. In the modern RF industry, engineers are sparing no effort to increase the PAE in order to increase the battery life; however, linearity requirements, such as ACLR for W-CDMA, E-UTRA for LTE, and ACPR for CDMA2K, must be obtained in order to achieve the basic power amplifier functionality. Detailed explanations will be provided in later sections. Other power amplifier design requirements and specifications also include gain, 2FO/3FO harmonic rejection, noise, stability, ruggedness, leakage power etc.

This thesis introduces the fundamental principles and knowledge of various types of power amplifiers and highlights their unique pros and cons among the different topologies. A high-efficiency, high-frequency switching mode power amplifier will be discussed mostly with regard to its design and measurement testing. Moreover, a conventional class E power amplifier output matching network will be designed using ADS (Advanced Design System) with the simulation results. Furthermore, basic power amplifier measurement will be performed using VNA, NVNA, and PSA.