High Efficiency Power Amplifier for IoT Applications: RF Path

IoT devices must remain operational for 10 years with one set of batteries. Most power is typically consumed by an RF power amplifier, which is necessary for transmitting data over a wireless radio channel in 5G networks. For this reason, the task of increasing the efficiency of an RF power amplifier is relevant. High efficiency can be achieved by using active element switching modes in combination with “synthetic” amplification methods. This article analyzes the energy characteristics of a Class D switching power amplifier with a filter for two configurations: voltage mode and current mode for various transistor saturation times (Duty Ratio). Based on the analysis of time diagrams, integral equations are written, the solution of which allows us to derive calculation formulas. The results of calculations are presented. It is shown that the mode of working with meanders is most advantageous, while the VMCD circuit should work at τsat≤π, and in the CMCD circuit should work at τsat≥π.