High-linearity RF Amplifier Design

Peter B. Kenington is the head of advanced development at Wireless Systems International Ltd. He holds a Ph.D. in Communications Engineering from the University of Bristol.

Introduction: Distortion. The Requirement for Linearity. Effect of Nonlinearity on a W-CDMA System. Requirement for Linearity in Adaptive Antenna Systems. Organization of the Text. Distortion in Amplifiers: Amplitude Distortion. Two-Tone Test. Calculation of Intermodulation Distortion Ratio. Signals. Examples. Phase Distortion. White Noise Testing of Amplifier Linearity. Spurious. Signals. Cross-Modulation. Modeling of Amplifier Nonlinearities. RF Power Amplifier Design: Introduction. Power Semiconductors. Class-A Amplifiers. Class-B Amplifiers. Class-AB Amplifiers. Class-C Amplifiers. Class-D Amplifiers. Class-E Amplifiers. Class-F Amplifiers. Class-G and H Amplifiers. Class-S Amplifiers. Biasing for Linear Operation. Sources of Inequality for IM Products. Feedback Linearisation Techniques: Introduction. Feedback Theory. RF Feedback. Modulation Feedback. Polar-Loop Transmitter. Cartesian Loop Transmitter. Noise Performance of a Cartesian Loop. Practical Considerations with the Cartesian Loop Transmitter. Feedforward Systems: Basic Operation. Multiple Feedforward Loops. General Properties and Advantages. Gain and Phase Matching. Error Amplifier Design. Power Efficiency. Effect of Power Loss in the Main-Path Delay Element. Efficiency Improvement of a Feedforward Amplifier. Linear Distortion Correction in a Feedforward System. Temperature Drift and Component Aging. System Examples. Summary of Requirements for the Major System Components. Location and Matching Considerations. Loop Instability. Application Areas. Potential Advantages. Practical Results. Predistortion Techniques: Introduction. RF and IF Predistortion. Baseband Predistortion. Adaptive (Baseband) Predistortion. Postdistortion Linearisation. IMD Cancellation at the Antenna. Linear Transmitters Employing Signal Processing: Introduction. Envelope Elimination and Restoration. Linear Amplification Using Nonlinear Components. Vector Locked Loop. Combined Analogue-Locked Loop Universal Modulator-CALLUM. Linear Amplification by Sampling Techniques. Efficiency Boosting Systems: Doherty. Adaptive Bias. Envelope Tracking. Class-H Amplification. Dual-Bias Control. Refernces.