The presented article outlines the changes that have occurred over the past quarter-century in the design and performance of micro class gas turbine engines. The primary goal is to determine the current stage of development in engine construction. To achieve this, a representative group of 83 micro-class engines was selected and categorized based on the date they were introduced into operation. The main performance criterion was the engine's thrust, as these types of engines are primarily used in short-lifespan unmanned aerial vehicles (UAVs). A rotational performance characteristic was identified for a family of engines grouped into three geometric series. These characteristics are presented in relative parameters, facilitating convenient implementation in UAV design. A new trend in fanjet engine construction was identified, where thrust generation is primarily driven by the mass flow of the working medium passing through the engine duct. This is observed in modern engines with thrust exceeding 20 daN. It was demonstrated that, while maintaining the same external dimensions, a contemporary engine can deliver three times the thrust of a similar engine designed at the beginning of the 21st century.