Advanced RF Power Amplifier Techniques for Modern Wireless and Microwave Systems

We recommend you to submit your preliminary or firm registration at least 4 weeks before course start to ensure a seat on the course.

TECHNOLOGY FOCUS 
In any system, the power amplifier (PA) is a critical component. It is typically the most costly single item and consumes most of the supply power. Knowledge of the possibilities for trading power per unit cost with efficiency and linearity often forms the basis for the entire system architecture design. 

The increasing use of linearisation techniques, and especially the emergence of high speed digital processing as an enabling technology to implement predistortion on the PA input signal, represent an important paradigm shift in PA design. The PA component can now be designed with more emphasis on efficiency, without the traditional constraints of meeting stringent linearity specs simultaneously. Maximising the utility of a lineariser in order to obtain optimum efficiency has thus become a new subject area in modern RF PA design 

COURSE CONTENT
This is a newly revised and updated 4-day RF PA design course, dealing with the theory and design of RF power amplifiers for wireless, satcom, and microwave applications. The course features in-depth treatment of PA design, PA modes, envelope power management, and non-linear effects. 

WHO SHOULD ATTEND
This course presents an overview, fundamentals, theory, practical and advanced power amplifier design which will be of interest to engineers and technical staff, managers and business development personnel who plan to pursue this technology, or compete with it. 

BENEFITS OF THIS COURSE
Enhance your understanding of:

• Power amplifier basic concepts, classes of operation, stability, linearity, bias technique
• Impedance matching techniques based on lumped elements and transmission lines
• High-efficiency techniques including well-know Classes F and E and newly developed classes, Efficiency Enhancement Techniques
• Power Amplifier Non-Linearities and Signal Environments
• PA Architecture

Monday
Power Amplifier Basics and Signal Environments 
Linear amplifier modes are described with quantitative analysis of power, efficiency and linearity tradeoffs in uncompensated form leading into a discussion of the device technologies currently available for PA design, including LDMOS, GaAs MESFET and HBT, SiC and GaN. Differences between bipolar and FET devices, and the effects of different kinds of parasitic effects will be discussed using circuit analysis and CAD models. Possibilities for tailoring the characteristics of devices for optimum efficiency and linearity will be presented. Particular emphasis is given to correct fundamental and harmonic matching. The impact of non-ideal harmonic terminations in practical Class AB designs will be analysed quantitatively. Various modulation systems (QPSK, EDGE, CDMA, OFDM) will be reviewed from the viewpoint of PA requirements.

• Introduction
• Classical PA Modes, Class A, Class AB, Class B, Class C
• PA Device Technology
• Optimum Device Characteristics for Class AB Operation
• Modulation Systems in Wireless Communications QPSK, GSM, EDGE, OFDM
• Effect of Signal Environment on RFPA Design

Tuesday
Class AB PA Design 
We will focus on practical issues in the design and manufacture of PAs for RF and MW Systems. Several design examples will be demonstrated, including a GaAs MESFET, a GaAs HBT, and a high power LDMOS device.

• Class AB circuits
• Harmonic Terminations
• CAD Design Examples

Wednesday
Power Amplifier Non-Linearity and Signal Environments 
We will focus on the non-linear properties of RF PAs, their source, manifestation, and methods for their characterization and modeling. A topical issue of great impact in modern linearised multi-carrier PA (MCPA) applications is memory effects.This subject will be illustrated with device measurements, and physical causes and remedies will be discussed. 

There will be a full treatment of bias network design.The process of converting a measured PA gain compression and AM-PM characteristic into spectral and EVM distortion, and the issues involved, will be discussed using several different modulation environments, including GSM-EDGE and WCDMA.

• Non-Linear PA Characteristics, Gain Compression, AM-PM
• Physical Origins of AM-PM, Analysis
• Peak to Average Power Ratio Issues in Modern Signal Environments
• Spectral Regrowth and EVM
• Power Series, Volterra Series. Model Fitting using measured Data
• Envelope simulation using EDGE, OFDM signals
• Memory Effects, definition, dynamic gain/phase measurements, causes and remedies
• Bias Network Design and Stability

Thursday
Efficiency Enhancement Techniques 
We will focus on the key issue of power back-off (PBO) efficiency, and LINC (linear amplification using non-linear components). Envelope management methods and tracking techniques in PA design will be presented.These include classical techniques such as the Chireix out-phasing method, the Khan and the Polar Loop envelope reconstruction approaches and the Doherty PA. Other less well-known techniques will be discussed, with emphasis on the broader band 
requirements, which future WiMax systems will require. Ultra high efficiency amplifier modes, Classes C, D, E, and F will be analyzed as possible candidates for LINC implementation and as stand-alone possibilities in systems using digital pre-distortion or feed forward linearization. 

Finally, PA architecture, including multistage effects, power combining techniques, and load pull design will be discussed. The course will conclude with a discussion on Microwave PA design at higher GHz frequencies and will address the various issues such as efficiency and linearity in the context of higher frequency and broader bandwidth applications.

• Power Combining Techniques
• Balanced and Push-Pull Operation
• Load-Pull Techniques
• Microwave PA Design

Book
Dr Cripps has written a book, that he would like to recommend, however, the book is not compulsory for the course.
Title: RF Power Amplifiers for Wireless Communications, Second Edition, 2006
ISBN 978-1-59693-018-6

Dr Cripps has also written
"Advanced Techniques in RF Power Amplifier Design", 2002.
ISBN 978-1-58053-282-2

Students may order the books over the Artech House website, http://www.artechhouse.com and receive a 15% discount by entering the promotion code "CEI" in the online order form.

Said about the course from previous participants:
"Very practical view of subjects, gives good input for technicians."
"A good trade-off between theory and practice, good basis for new designs."
"Concentration on insight, fundamentals, rules of thumb, practical attitude."
"Topics presented in a logical order. Dr Cripps brought out valuable personal observations upon several topics."
"Lecture material and notes backed up with appropriate and relevant demonstrations. Broad spectrum of information presented."
"Good overview about state-of-the-art techniques. Good input for my work."
"Good curriculum, nice sense of humor of the Professor."