Linear and Efficient Power Amplifier Design Based on a New Optimisation Method

Abstract

Power Amplifiers (PAs) are an integral part of any communication system. Power Amplifiers dominate the overall power consumption of the transmitter. In order to simplify the design procedure, simulations and measurements of PAs are usually done with simple signals such as continuous wave (CW). However, in reality the signals are modulated and this calls for a design requirement using complex modulated signals in order to achieve the optimal design. A Doherty Power Amplifier, operating at a frequency of 2.14 GHz, is designed and simulated using two-tone signals. A detailed study on linearity and efficiency constraints in the design of a DPA was carried out by simulating different combinations of efficiency vs linearity trade-offs. A study on the possibility of predicting the IMD components from the DPA was also done using a novel concept of IMD3 load-pull simulations. Finally, an emulation measurement study of a classical DPA using Chalmers Weblab setup for one-tone and two-tone has been done, where the time-varying load modulation is recreated in a measurement setup.