Simultaneous Application of Several Synthetic Methods for High Efficiency Radiofrequency Amplification

To achieve high efficiency while amplifying modern signals with a high crest factor, switching operating modes of transistors and synthetic amplification methods are used. The most promising of these are Kahn method (EER-Envelope Elimination and Restoration) and outphasing method. However, these methods have a number of limitations, to overcome which the possibilities of joint simultaneous application of several synthetic methods of radio frequency amplification are considered. To simultaneous application the outphasing method with bridge power combiner and power supply voltage pulse-step modulation, the dependence of average efficiency on number of supply voltage levels is determined. For EER amplifier, minimum required pulse width of PWM modulator is determined depending on the RF bandwidth of amplified signal and its dynamic range. Variants of these characteristics exchange for the number of supply voltage levels are discussed when pulse-step modulation is used together. Directions for further research formulated.