Power efficiency enhancement of transmitters using adaptive envelope tracking and shaping techniques for small payload space applications

With the rise of modular system architecture for distributed satellite systems with multiple small payloads instead of conventional larger spacecrafts, the efficient characterization of power budget and available power constraints become even more vital. In order to establish high data rate downlink com munications in small satellite applications, use of highly efficient, non - conventional power amplification techniques is going to be a key factor in future communication systems. The concept of having small, less power consuming and high data rate transmis sion system extends to vast number of applications like light weight Unmanned Aerial Vehicle (UAV) and hand - held communication modules etc. The idea is to study and develop an adaptive envelope tracking technique which should be able to dynamically supply power to Radiofreq uency power amplifier. Consequently, a n optimal control over system power consumption leads to enhanced efficiency. The amplifiers intended for such systems exhibit nonlinear behavior when it comes to operating at maximum output power an d cause distortion in adjacent bands. Introducing a power supply modulation block in combination with digital linearization techniques such as DPD offers considerable improvement. Th is thesis tests a dynamic power supply adaptive shaping technique f or LTE signals. In comparison to conventional fixed supply RF PAs, Envelope Tracking PA has resulted in improved linearity at the output as well as reduced unwanted power leakage into adjacent frequency channels. By imposing an isogain trajectory trough th e shaping function, we can optimize the available power for high data rate communications while keeping the intermodulation distortion at acceptable levels by considering a tradeoff between efficiency and computational loa