Feedforward Amplifiers for Wideband Communication Systems

Dedication. Preface. Acknowledgments. 1. Introduction. 1. Radio-Electric transmitters - Historical overview. 1.1 Arc and spark transmitters. 1.2 Multi-polar alternators. 1.3 Thermoionic vacuum tubes. 1.4 Discrete transistors. 1.5 Integrated transistors. 2. Digital communication systems. 2.1 Analog signal. 2.2 Discrete signal. 2.3 Digital signal. 2.4 Digital transmission. 2.5 Electromagnetic spectrum. 2.6 Modulation techniques. 2.7 Signal degradation. 2.7.1 Attenuation. 2.7.2 Noise. 2.7.3 Distortion. 2.8 Basic architectures of wireless transmitters. 2.8.1 Analog I/Q modulator vs. digital IF. 2.8.2 Other implementations. 3. Digital modulation. 3.1 Applications. 3.2 Phase Shift Keying. 3.3 Frequency Shift Keying. 3.4 Minimum Shift Keying. 3.5 Quadrature Amplitude Modulation. 3.5.1 I/Q offset modulation. 3.5.2 Differential modulation. 3.6 Broadband wireless access techniques. 2. Nonlinear distortion.1. Harmonic distortion. 1.1 Nth harmonic distortion coefficient. 1.2 Global harmonic distortion. 2. Intermodulation analysis. 2.1 2 tone intermodulation. 2.2 3 tone intermodulation. 3. Cross modulation (XMOD). 3.1Cross modulation (m>1). 4. Distortion measurement techniques. 4.1 Harmonic distortion measurement. 4.2 Third order distortion measurement. 4.2.1 Two tone procedure. 4.2.2 Third order intercept point (IP3). 4.3 Second order distortion measurement. 4.4 Cross modulation (Xmod) measurement. 5. Measurements of wideband digital signals. 5.1 Peak to average power ratio and CCDF curves. 5.2 Modulation quality measurements. 5.3 Code domain power. 5.4 Adjacent Channel Leakage Ratio (ACLR). 3. RF power amplifiers.1. Classification of power amplifiers. 2. Power amplifiers parameters. 2.1 The efficiency rate. 2.2 The back-off. 2.3 Power utilization factor (PUF). 3. Class A. 4. Class B. 5. Class AB (outphasing). 6. Class C. 7. Switching amplifiers. 7.1 Class D. 7.2 Class E. 7.3 Class F. 8. More operating modes. 4. Linearization techniques.1. Classification of the linearization techniques. 2. Feedback. 2.1 RF Feedback. 2.2 Envelope Feedback. 2.3 Envelope and phase Feedback. 2.4 Polar Loop. 2.5 Cartesian Loop. 3. Predistortion. 3.1 RF Predistortion. 3.1.1 Simple analog Predistortion. 3.1.2 Compound Predistortion. 3.2 Envelope Predistortion. 3.3 Baseband Predistortion. 4. Feedforward. 5. Efficiency enhancement techniques. 5.1 Bypassing. 5.2 Envelope Elimination and Restoration. 5.3 Bias Adaptation. 5.4 LINC. 5.5 Doherty Method. 5.6 CALLUM. 6. Comparison of linearization techniques. 5. Feedforward amplifiers.1. Feedforward linearization technique. 1.1 Frequency dependence. 1.2 Amplitude and phase adjustments. 1.3 Error amplifier distortion. 1.4 Isolation lack. 1.5 Main signal path loss. 2. Feedforward in wideband communications systems. 6. Implementation of Feedforward amplifiers.1. Simulation of the Feedforward architecture. 1.1 Simulation models. 1.2 Simulation of the error loop. 1.3 Simulation of the distortion cancellation loop. 1.4 The isolation effect. 2. Selection of the error amplifier. 3. The adjustment of the cancellation loops. 3.1 Delay lines. 3.1.1 Configuration. 3.1.2 Length tolerances. 3.1.3 Packaging. 3.1.4 System design. 3.2 An adjustment method for delay lines. 4. Distortion enhanced measurement techniques. 4.1 Spectrum analyzer mixer level